Double Star Measurements performed with a Meade 12mm Astrometric Eyepiece during 2019

[et_pb_section fb_built="1" _builder_version="4.4.7"][et_pb_row _builder_version="4.4.7"][et_pb_column _builder_version="4.4.7" type="4_4"][et_pb_text _builder_version="4.4.7" hover_enabled="0"]

Neil Webster, St Marys Platt, Kent TN15 8NF

 

Introduction

The following measurements (Table 1) were made throughout 2019 using a Meade 12mm astrometric illuminated reticle eyepiece plus 2.5x powermate attached to an Altair Astro 115mm triplet refractor (focal length 805mm, f7). The total magnification was 167.5x with a field of view of 0.3 degrees.

All final separation values were calculated from a calibration determined by the timing/transit method (Simple Techniques of Measurement: E.T.H. Teague, Chapter 12 in Observing and Measuring Visual Double Stars ed. Argyle, pub. Springer). This was performed at the start of the year and gave a final value of 12.53 +/- 0.01 arc-seconds per division on the reticle measurement scale.

Position Angle measurements were made using the now tried and tested method previously outlined in DSSC 25 which involves using the directional west arrow on the synscan handset to electronically steer the primary to the outer edge of the protractor scale. This enables repeated measurements to be made with ease without having to disable the tracking of the mount.

As before, 10 separation and 10 position angle measurements (N = 20) were performed on the same evening for each pair and the final results and associated uncertainties later calculated.

Extensive use was again made of the Astroplanner software. Separations throughout this year were all limited to a range from 15 to 70 arc-seconds. As in previous years magnitudes ranged from 0.5 to 8.5.

As most of these systems are comparatively wide the orbits are generally very long (1,000 years+) and, as a result, very few have attempted orbit calculations. Residuals (from the online version of 6th USNO Catalogue of Orbits of Visual Binary Stars) have, however, been given for the few systems calculated but none have a better than grade 4 certainty (Table 2).

Values from the Fourth Catalogue of Interferometric Measurements have provided a more extensive set of residuals but most of these are from 1991 which is 28 years before the author’s measurements. Although many of the systems have not changed in this time-interval some have and, in certain cases, this may possibly explain the larger residuals calculated (Table 3).

For the systems with larger residuals, alternative values have been calculated using the latest WDS measurements (mostly 2018) for comparison. As can be seen many of the residuals calculated from the more recent WDS figures are smaller. This would seem to imply measurable PA and separation changes to these systems over relatively short timescales (27 years maximum) which is surprising when the possible orbital periods are potentially in orders of thousands of years (Table 4).

 

References:

The Cambridge Double Star Atlas, (Mullany J. Tirion W. pub. Cambridge)

Observing and Measuring Visual Double Stars (ed. Argyle R.W. pub. Springer)

Washington Double Star Catalogue (Mason, B.D., Wycoff, G.L. & Hartkopf, W.I.):

http://ad.usno.navy.mil/proj/WDS

Sixth Catalogue of Orbits of Visual Binary Stars (Hartkopf, W.I., Mason, B.D. & Worley, C.E.):

http://www.usno.navy.mil/USNO/astrometry/optical-IR-prod/wds/orb6/sixth-catalog-of-orbits-of-visual-binary-stars

Fourth Catalogue of Interferometric Measurements of Binary Stars:

 http://www.usno.navy.mil/USNO/astrometry/optical-IR-prod/wds/int4

Astroplanner:

 http://www.astroplanner.net/

 

Table 1: Measurements

 

Pair

Comp

RA

Dec

Va

Vb

PA (o)

+/-

Sep (‘’)

+/-

Epoch

2019 +

N

Obs

 

 

 

 

 

 

 

 

 

 

 

 

 

S 457

AB

04531

-0117

7.93

8.07

354.0

0.1

40.8

0.2

.112

20

WST

STF 612

AB

04543

+0722

8.33

8.41

199.4

0.1

15.3

0.2

.112

20

WST

SHJ 49

AB

04590

+1433

6.06

7.43

306.0

0.1

39.0

0.1

.112

20

WST

STF 627

AB

05006

+0337

6.59

6.95

260.0

0.1

21.9

0.2

.112

20

WST

BVD 50

AB

05092

+1130

8.35

8.49

104.0

0.1

31.1

0.3

.112

20

WST

 

 

 

 

 

 

 

 

 

 

 

 

 

STF 696

AB

05228

+0333

4.95

6.76

28.5

0.1

32.0

0.2

.112

20

WST

STF 697

AB

05235

+1602

7.27

8.10

287.0

0.1

25.4

0.2

.123

20

WST

STF 734

AC

05331

-0143

6.67

8.35

243.0

0.1

29.2

0.2

.123

20

WST

STF 747

AB

05350

-0600

4.70

5.51

224.3

0.1

36.3

0.1

.123

20

WST

STF 855

AB

06090

+0230

5.68

6.68

114.6

0.1

29.1

0.2

.295

20

WST

 

 

 

 

 

 

 

 

 

 

 

 

 

STF 1062

AB

07229

+5517

5.76

6.71

316.9

0.1

13.8

0.1

.295

20

WST

STF 1315

AB

09128

+6141

7.33

7.65

27.8

0.1

25.1

0.1

.295

20

WST

STF 1321

AB

09144

+5241

7.79

7.88

98.2

0.1

16.7

0.2

.295

20

WST

STF 1369

AB

09354

+3958

6.98

7.98

149.8

0.1

25.1

0.1

.295

20

WST

STF 1415

AB

10178

+7104

6.65

7.27

168.0

0.1

16.5

0.2

.295

20

WST

 

 

 

 

 

 

 

 

 

 

 

 

 

STF 1603

AB

12081

+5528

7.82

8.26

84.0

0.1

22.6

0.1

.295

20

WST

STF 2241

AB

17419

+7209

4.60

5.59

14.0

0.1

29.6

0.2

.295

20

WST

STTA 163

AB

17563

+6237

7.77

7.59

52.6

0.1

54.1

0.2

.298

20

WST

STF 2273

AB

17592

+6409

7.31

7.63

282.3

0.1

22.6

0.1

.298

20

WST

STF 2308

AB

18002

+8000

5.70

6.00

232.0

0.1

18.7

0.1

.358

20

WST

 

 

 

 

 

 

 

 

 

 

 

 

 

STF 2278

AB

18029

+5626

7.78

8.14

28.9

0.2

36.3

0.1

.358

20

WST

STF 2420

AB

18512

+5923

4.77

8.26

316.0

0.2

37.6

0.1

.358

20

WST

SHJ 286

AB

19050

-0402

5.52

6.98

211.3

0.1

39.6

0.2

.701

20

WST

STF 2497

AB

19200

+0535

7.73

8.49

356.0

0.1

29.3

0.2

.701

20

WST

STFA 43

AB

19307

+2758

3.19

4.68

54.3

0.1

35.2

0.3

.703

20

WST

 

 

 

 

 

 

 

 

 

 

 

 

 

STF 2549

AD

19312

+6319

8.34

8.03

268.5

0.1

55.8

0.2

.358

20

WST

ARN 82

AB

19364

+3541

8.10

8.43

33.0

0.1

43.9

0.1

.717

20

WST

STFA 46

AB

19418

+5032

6.00

6.23

131.7

0.2

39.5

0.2

.717

20

WST

H 5 137

AB

19459

+3501

6.22

8.18

25.0

0.1

38.8

0.1

.717

20

WST

STFA 48

AB

19534

+2020

7.14

7.34

147.0

0.1

41.7

0.2

.703

20

WST

 

 

 

 

 

 

 

 

 

 

 

 

 

STF 2594

AB

19546

-0814

5.65

6.35

171.0

0.1

36.3

0.1

.701

20

WST

SHJ 314

AF

20060

+3547

6.78

7.30

28.0

0.1

36.3

0.1

.717

20

WST

WEB 12

AB

20078

+1950

8.36

8.37

77.0

0.1

40.1

0.1

.703

20

WST

S 738

AB

20106

+3338

7.76

8.43

106.0

0.1

42.6

0.1

.717

20

WST

S 735

AB

20113

-0008

7.16

7.98

211.0

0.1

56.4

0.1

.701

20

WST

 

 

 

 

 

 

 

 

 

 

 

 

 

S 740

AB

20142

+0635

7.77

8.06

192.2

0.1

43.9

0.1

.701

20

WST

STF 2664

AB

20196

+1300

8.07

8.34

321.0

0.1

27.1

0.2

.703

20

WST

STF 2687

AB

20264

+5638

6.37

8.31

117.5

0.1

25.1

0.1

.722

20

WST

S 749

AB

20275

-0206

6.76

7.51

188.9

0.1

60.1

0.3

.703

20

WST

STF 2691

AB

20297

+3808

8.14

8.45

32.0

0.1

16.3

0.1

.722

20

WST

 

 

 

 

 

 

 

 

 

 

 

 

 

STF 2690

A BC

20312

+1116

7.12

7.39

256.0

0.1

18.5

0.1

.703

20

WST

STF 2703

AB

20368

+1444

8.35

8.42

290.0

0.1

25.1

0.1

.703

20

WST

STF 2758

AB

21069

+3845

5.20

6.05

153.8

0.1

31.7

0.2

.722

20

WST

STF 2769

AB

21105

+2227

6.65

7.42

299.0

0.1

18.8

0.1

.703

20

WST

STT 447

AE

21395

+4144

7.67

8.48

42.8

0.2

29.1

0.2

.722

20

WST

 

 

 

 

 

 

 

 

 

 

 

 

 

S 800

AB

21538

+6237

7.07

7.91

145.0

0.1

62.7

0.1

.358

20

WST

ARY 45

AB

22083

+6959

7.86

8.11

206.7

0.1

66.7

0.2

.358

20

WST

STF 2872

A BC

22086

+5917

7.14

7.98

315.0

0.1

22.8

0.2

.358

20

WST

 

 

 

 

 

 

Table 2: Residuals from Known Orbits (6th Catalogue)

 

Pair

ADS (HIP)

Residual (O-C) PA (0)

Residual

 (O-C) Sep (‘’)

Orbit

Period (yrs)

 

Date

Grade

STF 1321 AB

7251

-1.0

-0.1

Chang

975

1972

4

STF 2241 AB

10759

-2.8

0.0

Kiselev

10 000

2009

5

STF 2308 AB

11061

+0.8

-0.1

Kiselev

18 000

1996

5

STFA 46 AB

12815

-1.3

-0.3

Marcy

135127

1999

4

STF 2758

14638

+1.3

-0.1

Pk

678

2006

4

 

(All Residuals: Observed – latest Catalogue measurement)

 

 

Table 3: Residuals from Fourth Catalogue of Interferometric Measurements

 

Pair

ADS (BDS)

HIP (TYC)

Epoch (catalogue)

Residual

 PA (0)

Residual

 Sep (‘’)

 

 

 

 

 

 

S 457 AB

(2400)

22716

1991.57

-0.7

-0.2

STF 612 AB

3514

(9165 00808)

1991.43

-0.4

-0.9

SHJ 49 AB

3579

23161

1991.46

+0.6

-0.3

STF 627 AB

3597

23287

2004.116

-0.1

+0.9

BVD 50 AB

 

23977

1991.665

+0.2

0.0

 

 

 

 

 

 

STF 696 AB

3962

25142

2002.901

-0.4

+0.4

STF 697 AB

3969

25207

1991.54

+1.3

-0.6

STF 734 AC

4150

26020

2002.901

-0.3

-0.1

STF 747 AB

4182

26199

1991.64

+0.6

+0.1

STF 855 AB

4749

29151

2002.977

+0.9

+0.4

 

 

 

 

 

 

STF 1062 AB

6012

35785

2002.996

+1.2

-0.9

STF 1315 AB

7226

45206

1991.59

+0.9

+0.3

STF 1321 AB

7251

45343

1991.81

+7.7

-0.8

Pair

ADS (BDS)

HIP (TYC)

Epoch (catalogue)

Residual

 PA (0)

Residual

 Sep (‘’)

 

 

 

 

 

 

STF 1369 AB

7438

47053

2003.311

-0.1

+0.2

STF 1415 AB

7705

50433

2003.251

+0.7

0.0

 

 

 

 

 

 

STF 1603 AB

8434

59176

1991.63

+1.6

+0.3

STF 2241 AB

10759

86614

1991.70

-1.5

-0.6

STTA 163 AB

(8295)

87815

1991.64

+2.6

-0.6

STF 2273 AB

10985

88071

1991.77

-0.9

+1.3

STF 2308 AB

11061

88136

2012.7725

+2.0

-0.8

 

 

 

 

 

 

STF 2278 AB

11035

88381

1991.60

+0.9

+0.1

STF 2420 AB

11779

92512

2003.628

-3.4

+1.1

SHJ 286 AB

12007

93717

2003.418

+1.7

+0.4

STF 2497 AB

(9208)

95017

1991.79

-0.6

-0.7

STFA 43 AB

12540

95947

2003.418

+0.8

+0.8

 

 

 

 

 

 

STF 2549 AD

12586

96002

1991.76

-2.4

+1.2

ARN 82 AB

(BD+35 3705)

(2667 00321)

1991.61

-1.4

+0.6

STFA 46 AB

12815

96895

2003.628

-2.0

+0.4

H 5 137 AB

12900

97442

2003.628

0.0

+0.6

STFA 48 AB

(9705)

97876

1991.69

+0.2

-0.4

 

 

 

 

 

 

STF 2594 AB

13087

97966

2003.418

+0.4

+0.6

SHJ 314 AF

13374

99002

2003.695

+0.3

+1.6

WEB 12 AB

 

(1625 00995)

1991.703

+0.2

-0.9

S 738 AB

13463

99409

1991.61

-0.6

+0.7

S 735 AB

(9961)

99476

1991.49

+1.7

+1.0

S 740 AB

(10012)

99729

1991.54

+0.4

+0.6

 

 

 

 

 

 

STF 2664 AB

(BD+12 4291)

100226

1991.49

-0.5

-0.5

STF 2687 AB

13870

100868

2003.629

+0.2

-0.7

S 749 AB

13868

100896

1991.46

+0.4

+0.2

Pair

ADS (BDS)

HIP (TYC)

Epoch (catalogue)

Residual

 PA (0)

Residual

 Sep (‘’)

STF 2691 AB

13919

101109

1991.68

+0.6

-0.9

STF 2690 A BC

13946

101233

1991.52

+1.2

+1.3

 

 

 

 

 

 

STF 2703 AB

(10161)

101700

1991.64

-0.1

-0.2

STF 2758 AB

14636

104214

1991.69

+5.8

+1.6

STF 2769 AB

14710

104539

2003.784

-0.2

+0.9

STT 447 AE

15186

(3191 00346)

1991.67

-1.8

+0.2

S 800 AB

15434

108073

1991.61

-0.1

+0.2

 

 

 

 

 

 

ARY 45 AB

(1225)

109275

1991.67

+0.1

+0.1

STF 2872 A BC

15670

(3981 01587)

1991.68

-0.9

+1.6

 

 

 

Table 4: Alternative Residuals: WDS

 

Pair

Epoch: WDS

(Fourth Catalogue)

Residual PA (0): WDS (Fourth Catalogue)

Residual Sep (): WDS (Fourth Catalogue)

STF 1321 AB

2018    (1991.81)

 0.0    (-0.8)

-0.3    (+7.7)

STF 1603 AB

2018    (1991.63)

-0.5    (+0.3)

+0.1   (+1.6)

STTA 163 AB

2017    (1991.64)

-0.4    (-0.6)

-0.2    (+2.6)

STF 2308 AB

2018    (2012.7725)

-0.2    (-0.8)

 0.0     (+2.0)

STF 2420 AB

2017    (2003.628)

-1.0    (+1.1)

+0.1   (-3.4)

 

 

 

 

STF 2549 AD

2018    (1991.76)

-2.0    (+1.2)

 0.0    (-2.4)

STFA 46 AB

2018    (2003.628)

-1.9    (+0.4)

-0.4    (-2.0)

S 735 AB

2018    (1991.61)

 0.0    (+1.0)

+0.4   (+1.7)

STF 2690 A BC

2018    (1991.52)

+0.4   (+1.3)

+0.8   (+1.2)

STF 2758 AB

2018    (1991.69)

+0.7   (+1.6)

-0.3    (+5.8)

 

 

 

 

STT 447 AE

2017    (1991.67)

-1.5    (+0.2)

+0.2    (-1.8)

STF 2872 A BC

2018    (1991.68)

-1.1    (+1.6)

+1.1    (-0.9)

 

[/et_pb_text][/et_pb_column][/et_pb_row][/et_pb_section]

Double Star Measurements with a Meade 12mm Astrometric Eyepiece in 2018

[et_pb_section bb_built="1"][et_pb_row][et_pb_column type="4_4"][et_pb_text _builder_version="3.22.1" text_text_shadow_horizontal_length="text_text_shadow_style,%91object Object%93" text_text_shadow_vertical_length="text_text_shadow_style,%91object Object%93" text_text_shadow_blur_strength="text_text_shadow_style,%91object Object%93" link_text_shadow_horizontal_length="link_text_shadow_style,%91object Object%93" link_text_shadow_vertical_length="link_text_shadow_style,%91object Object%93" link_text_shadow_blur_strength="link_text_shadow_style,%91object Object%93" ul_text_shadow_horizontal_length="ul_text_shadow_style,%91object Object%93" ul_text_shadow_vertical_length="ul_text_shadow_style,%91object Object%93" ul_text_shadow_blur_strength="ul_text_shadow_style,%91object Object%93" ol_text_shadow_horizontal_length="ol_text_shadow_style,%91object Object%93" ol_text_shadow_vertical_length="ol_text_shadow_style,%91object Object%93" ol_text_shadow_blur_strength="ol_text_shadow_style,%91object Object%93" quote_text_shadow_horizontal_length="quote_text_shadow_style,%91object Object%93" quote_text_shadow_vertical_length="quote_text_shadow_style,%91object Object%93" quote_text_shadow_blur_strength="quote_text_shadow_style,%91object Object%93" header_text_shadow_horizontal_length="header_text_shadow_style,%91object Object%93" header_text_shadow_vertical_length="header_text_shadow_style,%91object Object%93" header_text_shadow_blur_strength="header_text_shadow_style,%91object Object%93" header_2_text_shadow_horizontal_length="header_2_text_shadow_style,%91object Object%93" header_2_text_shadow_vertical_length="header_2_text_shadow_style,%91object Object%93" header_2_text_shadow_blur_strength="header_2_text_shadow_style,%91object Object%93" header_3_text_shadow_horizontal_length="header_3_text_shadow_style,%91object Object%93" header_3_text_shadow_vertical_length="header_3_text_shadow_style,%91object Object%93" header_3_text_shadow_blur_strength="header_3_text_shadow_style,%91object Object%93" header_4_text_shadow_horizontal_length="header_4_text_shadow_style,%91object Object%93" header_4_text_shadow_vertical_length="header_4_text_shadow_style,%91object Object%93" header_4_text_shadow_blur_strength="header_4_text_shadow_style,%91object Object%93" header_5_text_shadow_horizontal_length="header_5_text_shadow_style,%91object Object%93" header_5_text_shadow_vertical_length="header_5_text_shadow_style,%91object Object%93" header_5_text_shadow_blur_strength="header_5_text_shadow_style,%91object Object%93" header_6_text_shadow_horizontal_length="header_6_text_shadow_style,%91object Object%93" header_6_text_shadow_vertical_length="header_6_text_shadow_style,%91object Object%93" header_6_text_shadow_blur_strength="header_6_text_shadow_style,%91object Object%93" z_index_tablet="500"]

Neil Webster, St Marys Platt, Kent 

e-mail:             ******@gmail.com

 

Introduction

The following measurements were made throughout 2018 using a Meade 12mm astrometric illuminated reticle eyepiece plus 2.5x powermate attached to an Altair Astro 115mm refractor (focal length 805mm, f7). The total magnification was 167.5x with a field of view of 0.3 degrees.

Fewer measurements were made this year due to relocation which finally happened at the end of February. Serious observing, measuring and imaging did not begin until the middle of April. Although St Marys Platt is a much darker site than Bromley measurements are still limited to 8.5 magnitude due to the red light in the eyepiece. However, a Southerly aspect is now available so many of the measurements are of systems previously unavailable.

All final separation values were calculated from a calibration determined by the timing/transit method (Simple Techniques of Measurement: E.T.H. Teague, Chapter 12 in Observing and Measuring Visual Double Stars ed. Argyle, pub. Springer).

Position Angle measurements were made using the now tried and tested method previously outlined in DSSC 25 which involves using the directional west arrow on the synscan handset to electronically steer the primary to the outer edge of the protractor scale rather than turning off the mount motor for an unaided drift.

As before, 10 separation and 10 position angle measurements (N = 20) were performed on the same evening for each pair and the final results and associated uncertainties calculated.

Extensive use was again made of the Astroplanner software. Separations throughout the year were all limited to a range from 15 to 100 arc-seconds. Magnitudes ranged from 0.5 to 8.5.

As most of these systems are comparatively wide the orbits are generally very long (2,000 years+) and very few have accurate orbital calculations. Residuals (from the online version of 6th USNO Catalogue of Orbits of Visual Binary Stars) have been given for the few systems calculated but none have a better than grade 5 certainty (Table 2).

Values from the Fourth Catalogue of Interferometric Measurements have provided a more extensive set of residuals but most of these are from 1991 which is 26 years before the author’s measurements. Although many of the systems have not changed in this time some have and, in certain cases, this shows in the larger residuals calculated (Table 3).

For residuals greater than 1o in PA or 1” in separation relative proper motions have been analysed (Table 4). In certain cases differences between the components’ proper motions may provide a tentative explanation for the larger than average residuals obtained (Table 4).

Some systems have larger than anticipated residuals and alternative residuals have been calculated using the latest WDS measurements for comparison (Table 5).

References:

The Cambridge Double Star Atlas, (Mullany J. Tirion W. pub. Cambridge)

Observing and Measuring Visual Double Stars (ed. Argyle R.W. pub. Springer)

Washington Double Star Catalogue (Mason, B.D., Wycoff, G.L. & Hartkopf, W.I.):

http://ad.usno.navy.mil/proj/WDS

Sixth Catalogue of Orbits of Visual Binary Stars (Hartkopf, W.I., Mason, B.D. & Worley, C.E.):

http://www.usno.navy.mil/USNO/astrometry/optical-IR-prod/wds/orb6/sixth-catalog-of-orbits-of-visual-binary-stars

Fourth Catalogue of Interferometric Measurements of Binary Stars:

 http://www.usno.navy.mil/USNO/astrometry/optical-IR-prod/wds/int4

Astroplanner:

 http://www.astroplanner.net/

 

Table 1: Measurements

 

Pair

Comp

RA

Dec

Va

Vb

PA (o)

+/-

Sep (‘’)

+/-

Epoch

2018 +

N

Obs

                         

STTA 254

AB

00013

+6021

7.40

8.33

89.0

0.1

57.8

0.3

.742

20

WST

STF 3053

AB

00026

+6606

5.96

7.17

69.5

0.1

15.0

0.1

.742

20

WST

STTA 1

AB

00141

+7601

7.39

7.81

103.2

0.1

73.2

0.3

.742

20

WST

H 5 17

AB

00369

+3343

4.36

7.08

173.0

0.1

36.0

0.2

.809

20

WST

HJ 1986

AB

00396

+8445

7.96

8.50

67.0

0.1

40.3

0.2

.742

20

WST

                         

STFA 1

AB

00464

+3057

7.25

7.43

46.8

0.1

47.8

0.2

.809

20

WST

H 5 82

AB

00474

+5106

7.97

8.35

75.0

0.1

56.8

0.3

.742

20

WST

STF 88

AB

01057

+2128

5.27

5.45

159.5

0.1

29.2

0.2

.802

20

WST

STF 90

AB

01058

+0455

6.39

7.26

83.5

0.2

32.7

0.2

.802

20

WST

STF 98

AB

01129

+3205

7.02

8.14

250.0

0.1

20.0

0.1

.802

20

WST

 

 

 

 

 

 

 

 

 

 

 

 

 

STF 100

AB

01137

+0735

5.22

6.27

63.2

0.1

23.2

0.2

.802

20

WST

HJ 2028

AB

01166

+7402

7.06

7.88

203.5

0.1

62.6

0.3

.772

20

WST

STT 30

AC

01256

+3133

8.09

8.06

105.7

0.1

56.7

0.3

.802

20

WST

S 398

AB

01284

+0758

6.34

8.02

100.4

0.1

68.9

0.3

.802

20

WST

STF 222

AB

02109

+3902

6.05

6.71

36.0

0.1

16.5

0.2

.809

20

WST

 

 

 

 

 

 

 

 

 

 

 

 

 

S 405

AB

02128

+7941

6.47

7.15

276.7

0.1

55.5

0.3

.772

20

WST

STTA 26

AB

02197

+6002

6.95

7.30

200.5

0.1

62.9

0.3

.772

20

WST

CTT3

AB

02359

+6338

7.78

8.30

87.5

0.1

88.1

0.4

.802

20

WST

STTA 28

AB

02390

+6235

6.65

7.56

147.9

0.1

67.9

0.3

.802

20

WST

STTA 31

AB

03009

+5940

7.33

8.03

230.6

0.1

73.7

0.1

.802

20

WST

 

 

 

 

 

 

 

 

 

 

 

 

 

STTA 94

AB

08362

+1347

7.39

8.11

132.7

0.1

43.2

0.2

.298

20

WST

S571

AD

08399

+1933

7.31

6.67

241.9

0.1

92.1

0.4

.342

20

WST

S571

AC

08399

+1933

7.31

7.47

157.5

0.1

45.7

0.3

.342

20

WST

STF 1254

AC

08404

+1040

6.52

7.61

342.6

0.2

62.5

0.1

.298

20

WST

STF 1268

AB

08467

+2846

4.13

5.99

307.9

0.2

30.7

0.1

.298

20

WST

 

 

 

 

 

 

 

 

 

 

 

 

 

STF 1283

AB

08499

+1450

7.66

8.45

123.0

0.1

16.4

0.3

.298

20

WST

STTA 96

AB

08520

+2543

7.65

8.45

312.0

0.1

50.0

0.1

.298

20

WST

STTA 97

AB

09084

+2732

8.30

8.31

273.6

0.1

51.5

0.2

.298

20

WST

STF 1575

AB

11520

+0850

7.43

7.89

211.0

0.1

30.5

0.2

.342

20

WST

STF 1579

AB D

11551

+4629

6.68

6.97

113.5

0.1

62.5

0.1

.523

20

WST

STF 1579

CD

11551

+4629

8.32

6.97

117.0

0.1

61.9

0.2

.523

20

WST

STTA 114

AB

12002

+3644

7.48

8.39

83.1

0.1

86.3

0.3

.523

20

WST

STTA 116

AB

12019

+0006

7.81

8.49

177.4

0.1

73.2

0.3

.324

20

WST

STF 1603

AB

12081

+5528

7.82

8.26

84.5

0.2

22.5

0.1

.523

20

WST

STF 1627

AB

12182

-0357

6.55

6.90

196.1

0.1

20.9

0.2

.342

20

WST

 

 

 

 

 

 

 

 

 

 

 

 

 

STF 1649

AB

12316

-1104

7.97

8.43

194.0

0.1

15.7

0.2

.342

20

WST

STF 1657

AB

12351

+1823

5.11

6.33

271.8

0.2

20.2

0.2

.496

20

WST

STF 1677

AB

12453

-0353

7.30

8.12

348.4

0.2

15.6

0.2

.342

20

WST

STF 1678

AB

12454

+1422

7.16

7.68

170.0

0.1

37.5

0.1

.517

20

WST

STF 1685

AB

12519

+1910

7.31

7.78

202.1

0.1

16.0

0.1

.517

20

WST

 

 

 

 

 

 

 

 

 

 

 

 

 

STF 1692

AB

12560

+3819

2.85

5.52

229.8

0.1

19.5

0.3

.517

20

WST

STF 1740

AB

13237

+0243

7.13

7.39

74.7

0.2

25.6

0.2

.342

20

WST

H 570

AC

13309

+2414

7.67

8.28

256.0

0.1

76.8

0.3

.517

20

WST

S 656

AB

13504

+2117

6.93

7.37

208.5

0.1

86.2

0.1

.534

20

WST

SHJ 179

AB

14255

-1958

6.61

7.16

295.8

0.1

35.0

0.3

.496

20

WST

 

 

 

 

 

 

 

 

 

 

 

 

 

STTA 131

AB

14538

-0024

7.47

8.14

215.8

0.1

83.0

0.3

.342

20

WST

HN 28

AB

14575

-2125

5.88

8.18

306.0

0.1

25.0

0.1

.496

20

WST

STF 1919

AB

15127

+1917

6.71

7.38

10.9

0.2

23.6

0.1

.501

20

WST

SHJ 195

AB

15145

-1826

6.79

8.32

140.7

0.2

47.5

0.3

.496

20

WST

SHJ 202

AB

15282

-0921

6.95

7.61

132.3

0.1

52.0

0.3

.496

20

WST

 

 

 

 

 

 

 

 

 

 

 

 

 

H 3 7 AC

AC

16054

-1948

2.59

4.52

20.0

0.1

13.0

0.2

.545

20

WST

STF 2007

AB

16060

+1319

6.89

7.98

322.1

0.1

37.5

0.1

.501

20

WST

H 5 6 AC

 

16120

-1928

4.35

6.60

336.5

0.1

41.3

0.2

.545

20

WST

SHJ 225

AB

16201

-2003

7.39

8.08

332.8

0.2

47.1

0.2

.638

20

WST

STFA 34

AB

17346

+0935

5.80

7.50

191.0

0.1

41.6

0.3

.501

20

WST

 

 

 

 

 

 

 

 

 

 

 

 

 

STF 2185

AC

17348

+0601

7.46

8.43

253.0

0.1

93.2

0.4

.501

20

WST

STF 2202

AB

17446

+0235

6.13

6.47

93.6

0.1

20.7

0.2

.501

20

WST

S 694

AB

17521

+0107

6.67

7.26

237.7

0.1

79.3

0.3

.501

20

WST

SHJ 264

AB C

18187

-1837

6.86

7.63

51.1

0.1

18.1

0.2

.545

20

WST

PLT 3

AB

18510

-2018

7.04

7.55

101.0

0.1

93.6

0.1

.545

20

WST

 

 

 

 

 

 

 

 

 

 

 

 

 

STTA 176

AB

18545

+0154

7.45

7.51

111.6

0.1

94.3

0.4

.509

20

WST

STF 2417

AB

18562

+0412

4.59

4.93

103.1

0.1

22.7

0.2

.509

20

WST

SHJ 286

AB

19050

-0404

5.52

6.98

211.0

0.1

39.3

0.2

.509

20

WST

STTA 178

AB

19153

+1505

5.69

7.64

266.7

0.2

89.6

0.3

.509

20

WST

STF 2497

AB

19200

+0535

7.73

8.49

356.0

0.1

30.6

0.2

.511

20

WST

 

 

 

 

 

 

 

 

 

 

 

 

 

HJ 599

AC

19407

-1618

5.42

7.65

40.8

0.2

45.3

0.2

.545

20

WST

STFA 45

AB

19431

-0818

7.11

7.56

146.1

0.1

97.0

0.4

.511

20

WST

STF 2594

AB

19546

-0814

5.65

6.35

169.9

0.1

36.0

0.2

.511

20

WST

STTA 198

AB

20066

+0735

7.12

7.55

185.0

0.1

64.6

0.3

.511

20

WST

S 735

AB

20113

-0008

7.16

7.98

211.0

0.1

56.0

0.2

.511

20

WST

 

 

 

 

 

 

 

 

 

 

 

 

 

S 740

AB

 

20142

+0635

7.77

8.06

191.6

0.1

43.6

0.2

.511

20

WST

S 749

AB

20275

-0206

6.76

7.51

189.0

0.1

60.6

0.3

.511

20

WST

STTA 211

AB

20493

+5845

6.85

7.88

268.2

0.1

94.9

0.4

.807

20

WST

S 788

AB

21238

-0635

7.65

8.27

93.2

0.1

58.1

0.3

.638

20

WST

STFA 56

AB

21377

+0637

6.18

7.50

348.3

0.1

38.8

0.2

.826

20

WST

STF 2816

AD

21390

+5729

5.73

7.53

338.7

0.2

20.6

0.2

.807

20

WST

STTA 222

AB

21441

+0709

7.49

8.47

257.5

0.1

87.4

0.1

.826

20

WST

ES 382

AC

21509

+3240

8.28

8.42

322.0

0.1

58.1

0.3

.826

20

WST

STF 2840

AB

21520

+5548

5.64

6.42

196.8

0.2

18.1

0.2

.807

20

WST

S 825

AB

23100

+3651

7.78

8.26

318.0

0.1

67.3

0.2

.809

20

WST

 

 

 

 

 

 

 

 

 

 

 

 

 

STF 2985

AB

23100

+4758

7.21

8.02

256.2

0.1

15.2

0.1

.809

20

WST

SHJ 355

AC

23300

+5833

4.87

7.23

268.5

0.1

75.0

0.1

.809

20

WST

 

 

Table 2: Residuals from Known Orbits

 

Pair

ADS (HIP)

Residual (O-C) PA (0)

Residual

 (O-C) Sep (‘’)

Orbit

Period (yrs)

 

Date

Grade

 

 

 

 

 

 

 

 

H N 28 AB

9446

-1.1

-0.9

Hale

2130

1994

5

S 825 AB

16558

-0.7

+0.4

Kiselev

110 000

2009

5

S 825 AB

16558

-1.8

+0.5

Kiselev

110 000

2009

5

S 825 AB

16558

-0.8

+0.1

Kiselev

110 000

2009

5

 

 

(All Residuals: Observed – latest Catalogue measurement)

 

Table 3: Residuals from Fourth Catalogue of Interferometric Measurements

 

Pair

ADS (BDS)

HIP (TYC)

Epoch (catalogue)

Residual

 PA (0)

Residual

 Sep (‘’)

STTA 254 AB

(12693)

99

1991.61

-0.4

0.0

STF 3053 AB

1

207

2003.770

-0.7

0.0

STTA 1 AB

(71)

1124

1991.67

-0.3

-0.7

H 5 17 AB

 

 

 

 

 

HJ 1986 AB

(+83)

(4619 00293)

1991.69

+0.1

-0.1

 

 

 

 

 

 

STFA 1 AB

639

3617

2003.804

+0.5

+0.7

H 5 82 AB

(417)

3698

1991.76

-0.1

+1.4

STF 88 AB

899

5131

2003.845

-0.2

-0.8

STF 90 AB

903

5141

2003.845

+0.5

-0.1

STF 98 AB

988

5671

1991.45

+1.3

+0.4

 

 

 

 

 

 

STF 100 AB

996

5737

2003.866

+0.1

+0.6

HJ 2028 AB

(BD+73)

5950

1991.67

-0.2

+0.8

STT 30 AC

1134

6668

1991.54

+0.1

0.0

S 398 AB

(770)

6868

1991.54

+0.9

-0.1

STF 222 AB

1683

10176

2003.875

+0.1

0.0

 

 

 

 

 

 

S 405 AB

(1094)

10309

1991.73

+0.2

-0.2

STTA 26 AB

(1193)

10856

1991.56

+0.2

-0.5

CTT3 AB

(BD+62 423)

12081

1991.66

-0.4

+0.6

STTA 28 AB

(1329)

12346

1991.56

+0.1

+0.1

STTA 31 AB

(BD+59 582)

14049

1991.71

+0.4

+0.1

 

 

 

 

 

 

STTA 94 AB

 

42193

1991.72

-0.3

-0.2

S 571 AD

6915

(1395 02711)

1991.63

+0.1

-0.7

S 571 AC

6915

(1395 02711)

1991.61

+1.0

+0.5

STF 1254 AC

6921

42549

1991.59

0.0

-0.8

STF 1268 AB

6988

43100

2003.283

+0.2

+0.5

 

 

 

 

 

 

STF 1283 AB

7031

43359

1991.56

+0.1

0.0

STTA 96 AB

 

43535

1991.57

-1.2

+1.5

STTA 97 AB

 

44858

1991.72

-0.1

-0.2

STF 1575 AB

8327

57858

1991.70

+1.0

0.0

STF 1579   AB D

8347

58112

1991.73

-0.3

-0.5

 

 

 

 

 

 

STTA 114 AB

(5993)

58530

1991.80

+0.7

-0.5

STTA 116 AB

 

58678

1991.66

0.0

+0.4

STF 1603 AB

8434

59176

1991.63

+2.1

+0.2

STF 1627 AB

8505

59984

2003.284

+0.4

+1.1

STF 1649 AB

8585

61127

1991.67

+0.1

+0.2

 

 

 

 

 

 

STF 1657 AB

8600

61418

2003.284

+1.7

+0.3

STF 1677 AB

8657

62234

1991.51

+0.5

-0.5

STF 1678 AB

8659

62248

2003.251

-2.1

+0.8

STF 1685 AB

8690

62783

1991.63

-0.6

0.0

STF 1692 AB

8706

63125

2003.284

+1.2

+0.4

 

 

 

 

 

 

STF 1740 AB

8883

65352

1991.31

0.0

-0.7

H 570 AC

8929

65921

1991.66

-0.7

+1.3

S 656 AB

(6647)

67543

1991.75

+0.3

+0.4

SHJ 179 AB

9258

70518

2003.481

+0.4

+0.8

STTA 131 AB

 

72888

1991.52

+1.3

-1.1

 

 

 

 

 

 

HN 28 AB

9446

73184

1991.48

+1.4

+0.8

STF 1919 AB

9535

74432

2003.284

+0.7

+0.5

SHJ 195 AB

(17 4283)

(6174 00156)

1991.58

+0.8

+0.4

SHJ 202 AB

(7268)

75718

1991.52

-0.3

-0.1

H 3 7 AC

9913

78820

2005.498

+0.2

-0.6

 

 

 

 

 

 

STF 2007 AB

9922

78875

2003.418

-0.3

-0.3

H 5 6 AC

9951

79374

2003.418

-0.4

+0.5

SHJ 225 AB

(7575)

80024

1991.53

0.0

+0.4

STFA 34 AB

10635

85998

2003.418

+0.8

+0.2

STF 2185 AC

10638

86024

1991.52

+9.2

+6.9

 

 

 

 

 

 

STF 2202 AB

10750

86831

2003.290

+0.5

+0.3

S 694 AB

(8198)

87448

1991.67

+0.4

-0.6

SHJ 264    AB C

11240

(6269 04010)

2009.668

-0.4

+1.2

PLT 3 AB

 

92491

1991.72

+0.1

+0.4

STTA 176 AB

(8894)

92794

1991.81

-1.0

-0.4

 

 

 

 

 

 

STF 2417 AB

11853

92946

2003.580

-0.5

+0.6

SHJ 286 AB

12007

93717

2003.418

+1.4

+0.1

STTA 178 AB

(9149)

94624

1991.57

-0.3

-0.2

STF 2497 AB

(9208)

95017

1991.79

-0.6

+0.6

HJ 599 AC

12767

96808

2003.628

-0.7

+0.6

 

 

 

 

 

 

STFA 45 AB

(9525)

97016

1991.82

+0.3

+0.3

STF 2594 AB

13087

97966

2003.418

-0.7

+0.3

STTA 198 AB

13379

99055

1991.49

-0.6

-0.4

S 735 AB

(9961)

99476

1991.49

+1.7

+0.6

S 740 AB

(10012)

99729

1991.59

-0.2

+0.3

 

 

 

 

 

 

S 749 AB

13868

100896

1991.46

+0.5

+0.7

STTA 211 AB

(10577)

102775

1991.72

+1.9

-3.0

S 788 AB

(10943)

105641

1991.66

+1.3

+3.2

STF 2816 AD

15184

106886

2003.620

0.0

+0.9

STF 2840 AB

15405

107930

2003.621

+1.1

+0.4

 

 

 

 

 

 

S 825 AB

16558

114390

1991.76

-0.5

+0.1

STF 2985 AB

16557

114385

2012.6746

+0.5

-0.6

SHJ 355 AC

16795

115990

1991.59

-0.3

-0.6

 

 

 

 

 

 

 

 

Table 4: Doubles with significant proper motion differences

 

(All Proper Motions: WDS 2018)

Pair

Comp

Epoch

μα

μδ

μα

μδ

Δθ

(o)

Δρ  

(‘’)

H 5 82

AB

1991

-026

-024

+017

+004

-0.1

+1.4

STF 98

AB

1991

+013

-009

+013

-009

+1.3

+0.4

S 571

AC

1991

-036

-012

-035

-014

+1.0

+0.5

STTA 96

AB

1991

-004

-038

-047

-001

-1.2

+1.5

STF 1575

AB

1991

-010

-050

+008

-051

+1.0

0.0

 

 

 

 

 

 

 

 

 

STF 1603

AB

1991

-178

-017

-180

-033

+2.1

+0.2

STF 1627

AB

2002

-014

+022

-012

+031

+0.4

+1.1

STF 1657

AB

2003

-004

+023

-001

+025

+1.7

+0.3

STF 1678

AB

2003

-050

+004

+081

-044

-2.1

+0.8

STF 1692

AB

2003

-233

+055

-204

+088

+1.2

+0.4

 

 

 

 

 

 

 

 

 

H 570

AC

1991

+006

+019

-055

-019

-0.7

+1.3

STTA 131

AB

1991

+021

-058

+001

+010

+1.3

-1.1

H N 28

AB

1991

+103

-173

+010

-017

+1.4

+0.8

STF 2185

AC

1991

+012

-069

-459

+377

+9.2

+6.9

SHJ 264

AB C

2009

+001

-004

+000

-001

-0.4

+1.2

 

 

 

 

 

 

 

 

 

STTA 176

AB

1991

+006

-062

+000

-014

-1.0

-0.4

SHJ 286

AB

2003

+022

-026

+000

-039

+1.4

+0.1

S 735

AB

1991

+025

-028

-014

-010

+1.7

+0.6

STTA 211

AB

1991

-004

-002

+131

+100

+1.9

-3.0

S 788

AB

1991

-129

-004

-015

-044

+1.3

+3.2

 

 

 

 

 

 

 

 

 

STF 2840

AB

2003

+019

-001

+013

+013

+1.1

+0.4

 

Table 5: Alternative Residuals: WDS

 

Pair

Epoch (WDS)

Residual PA (0) (Fourth Catalogue)

Residual Sep () (Fourth Catalogue)

 

 

 

 

STF 1603 AB

2015

+2.1     (+2.1)

+0.4  (+0.2)

STF 1678 AB

2017

0.0       (-2.1)

-0.2   (+0.8)

STTA 131 AB

2017

-0.2      (+1.3)

+0.2  (-1.1)

STF 2185 AC

2015

-0.6      (+9.2)

+0.4  (+6.9

SHJ 286 AB

2017

+0.5     (+1.4)

-0.3   (+0.1)

 

 

 

 

S 735 AB

2015

0.0       (+1.7)

+0.4  (+0.6)

S 788 AB

2017

+0.1     (+1.3)

+0.6  (+3.2)

 

[/et_pb_text][/et_pb_column][/et_pb_row][/et_pb_section]

Classic Doubles

[et_pb_section bb_built="1"][et_pb_row][et_pb_column type="4_4"][et_pb_text _builder_version="3.12"]

By Neil Webster

CASTOR: a six-star system

αGEM Σ 1110

RA 07 35
Dec 31 53

Castor was discovered in 1678 by G.D. Cassini and formally classified as a true “binary” in 1803 by William Herschel. The system lies at a distance of about 52 light years and is a six star system.

The AB components comprise two blue-white stars separated by 5 arc seconds with magnitudes 1.9, 3.0 and spectral types A1V and A2V and an orbital period of 467 years. These are, in turn, spectroscopic binaries giving a four-star configuration.
In addition, a faint orange companion C star (magnitude 8.9 – 9.60) at a separation of 70.5” can be seen. This is, in fact, two orange dwarf stars (Spectral types M0V) that orbit one another in less than a day and is an eclipsing binary to our line of sight known as YY Gem.

The orbital period of the AB to C system is unknown but is thought to be of the order of 10,000 years.
An amazing sextuple system!!

REGULUS

αLEO Σ II 6

RA 10 08
Dec 11 58

Regulus is a four star system comprising two stellar pairs. The blue-white primary (B7V, 3.8 solar masses) pairs with a yet to be visually observed hypothesised White Dwarf star of 0.3 solar masses (detected via spectroscopy). These orbit over a short 40 day period. Regulus is observed to be spinning rapidly with a distorted shape (possible due to gravitational interaction with the white dwarf?).

At a separation of 177 arc seconds lies the secondary which is also a contained binary common proper motion pair with an orbital period of 2000 years. The two components have spectral types K2V and M4V with magnitudes 8.14 and 13.5.

Mizar and Alcor

RA 13 23 55.5
Dec 54 55 31

Mizar (magnitude 2.23, spectral class A1V) was first seen visually by Castelli in 1617 and through a telescope in 1650. It was one of the first double stars to be photographed by Bond in 1857. Its companion can be seen clearly at a separation 0f 14 arc seconds. Mizar A was also the first star found to be a double via spectroscopy (1889) and later its companion B (also A class) was also shown to be a spectroscopic binary making Mizar a quadruple system.

At a larger separation of 707 arc seconds lies Alcor (3.99, A5V) which is also a spectroscopic binary with a red dwarf companion.

Mizar and Alcor’s proper motions have long been observed to be similar but as they are part of the Ursa Major moving group a true gravitational connection between the two was in doubt. However, it has recently been proven (2009) by two separate teams that Mizar and Alcor represent a true binary system at a distance of about 83 light years.

Algieba

Gamma LEO
RA 10 19 58
Dec 19 50 29

Algieba is a true double star comprising two giants with yellow-white colourations at an angular separation of 4 arc seconds. It was first observed by William Herschel in 1782.

The primary star (K0III, 2.28) has a surface temperature of 4, 470 K, a luminosity 180 x that of the Sun and a diameter 23 x the Sun.

The companion star (G5111, 3.64) has a temperature of 4, 980 K a luminosity of 50 Suns and a diameter 10 times the Sun.
The orbital period is 500 years.

Iota Cancri

RA 08 46 42
Dec 28 45 36

The A component lies at a distance of 298 light years and is a G8II spectral type with apparent magnitude 4.02. This yellow/orange star has evolved off the Main Sequence and has a high Fe abundance.

Its companion is a blue-white Main Sequence star (A3V) with magnitude 6.57 and lies at a distance of 2800 A.U.
The angular separation is 30.6 arc seconds and the orbital period is a staggering 65, 000 years!

The pair are often referred to as the “Spring Albireo”.

Cor Caroli

RA 12 56 02
Dec 38 19 06

Cor Caroli (Charles’ Heart) was first observed by William Herschel and named in honour of Charles I (or II?) in 1660. It is a binary system at a distance of 110 light years with an angular separation of 19.6 arc seconds.

The primary is an A0 “chemically peculiar” star whose magnitude varies between 2.84 and 2.98 over a period of 5.47 days. This variability is thought to be due to a powerful magnetic field (5000x that of the Earth) giving rise to starspots that vary in intensity during the star’s rotation period.

The secondary is an F-type Main Sequence star of magnitude 5.60.

It is suspected that each component may also be a spectroscopic binary.

Virtually no change has been observed in the system’s configuration since 1830 leading to a calculated large orbital period of 7, 900 years.

Iota Bootis

RA 14 16
DEC 51 22

Iota Bootis (Asellus Secundus: Second Donkey Colt??) lies at an approximate distance of 97 light years and is a true double with a third very faint unrelated member,
The primary is an A-type Main Sequence dwarf that is a Delta Scuti variable star. Precise measurements are needed but the magnitude varies between 4.73 and 4.78 over separate pulsation periods of 38.22 and 30.55 minutes.
B is a A2 type star of apparent magnitude 8.27 (7.5).

Kappa Bootis

RA 14 13
DEC 51 47

Kappa Bootis (Asellus Tertius: third donkey colt) lies at a distance of 155 light years and is a triple star system.

The primary is an A7 subgiant (magnitude 4.54) with a surface temperature of 7830K. It is about to end its H-core burning phase and swell to a Red Giant. It is classified as a Delta Scuti variable with a period of 1.56 hours and has a faint binary companion (combined orbital period of 4.9 years).

The secondary (magnitude 6.6) is an F1V dwarf star with an estimated surface temperature of 6835K.

The primary and secondary orbit over at least 6,000 (from observed partial orbit) to 8,700 (theoretical) years.

Mu Bootis

RA 15 24
DEC 37 23

Mu Bootis/Alkalurops (“club”, “shepherd’s Staff”) is a triple system at a distance of 121 light years.

The primary is a yellow-white magnitude 4.31, F-type subgiant that is suspected to be variable and to have an orbiting companion.

At a separation of 109.4 arc-seconds lies the main binary secondary system of two G1 Dwarf stars (magnitudes 7.2, 7.8) orbiting over a 260 year period at an average separation of 2.2 arc-seconds.

Delta Cyg

RA 19 45
DEC 45 08

The dominant primary is a late Main Sequence B class supergiant star of magnitude 2.9, with a luminosity 180 x the Sun, a radius of 4.7 solar radii and a mass of 3.5 solar masses. It is known to be spinning rapidly (135 km/s at the stellar equator) producing an ellipsoidal shape.

The secondary is a yellow-white F-class star with a luminosity 6x the Sun and a mass of 1.5 solar masses. Its magnitude is 6.3 and as it is only 2.5 arc seconds from the primary it can be a challenge requiring steady, clear seeing! The position angle is 217 degrees.

A further two companion stars have been reported consisting of two pairing each 3 arc-seconds apart lying at distances of 42 and 148 arc seconds from the primary. Other sources report a single orange companion however??

AB has an orbital period of 918 years and lies at a distance of 170 light-years.

Albireo (Beta Cyg)

RA 19 30
DEC 27 57

A classic “showcase double” Albireo is actually a triple (or maybe quintuple) system and was first observed by Flamsteed in 1691.

The primary is an orange class K helium fusing star with a temperature of 4400 K, a luminosity 950 x the Sun, a radius of 50 solar radii and a mass 5x that of the Sun. Spectral analysis revealed it to have a varying radial velocity and a companion was clarified by speckle interferometry. It is a late class B9 dwarf star with a temperature of 11,000 K, a luminosity 0f 100 Suns and a mass 3.2 x that of the Sun. Partial orbit measurements have led to period estimates ranging from 100 – 213 years. The two stars are separated by 0.4 arc-seconds.

The secondary blue star is a B8 dwarf with a temperature of 12,100 K, a luminosity of 190 Suns and a mass of 3.3 Suns. It is a rapid rotator (250 km/s at the equator) completing an orbit in 0.6 Earth days. This gives rise to a surrounding disc of gas.

It is not certain that Albireo is a true “binary system” but, if it is, it has an orbital period of around 100,000 years.

Epsilon Lyra: “Double-Double”

RA 18 44
DEC 39 40

This system consists of four A-class white stars organised into two pairs of binaries.

Epsilon 1 has two stars of magnitudes 4.7 and 6.2 separated by 2.6 arc-seconds orbiting one another in around 1200 years.
Epsilon 2 has stars of magnitudes 5.1 and 5.3 orbiting in a period of 600 years (less precise).

The two systems are thought to orbit one another in about 1000 years and are currently separated by 208 arc seconds.
Precise measurements only began in the 1980s but in 1986 a further companion star was revealed by interferometry giving a five-star system.

However, it is thought that other surrounding faint stars could be part of the system and that the total count could be ten revealing a complex, fascinating gravitational world.

Rasalgethi (α Her)

A 17 14
DEC 14 23

Rasalgethi (Emperor’s Seat) is a triple (quintuple?) system lying 380 light years away.

The primary (magnitude 3.5) is a M5IIvar red bright giant that varies by a magnitude over a 14 year period. It is near the end of its life and undergoing mass-loss giving it an extended gaseous envelope. Speckle interferometry has further hinted at a very close companion star.

The secondary is a double star consisting of a primary yellow giant (G5III) and a secondary yellow-white dwarf (F2V) with a combined magnitude of 5.4).

The overall orbit is around 3600 years.

Nu Draco

RA 17 32
DEC 55 11

Nu Draco consists of two white dwarf stars (A6V, A4m both magnitude 4.9) at a distance of 99 light years and separated by 63.4 arc seconds.

The secondary is also a spectroscopic binary with a low mass companion completing an orbit every 38.6 days.
The overall system has an orbital period of 44,000 years.

61 Cyg

RA 21 07
DEC 38 45

61 Cyg was the first system apart from the Sun to have its stellar parallax and distance measured. The distance measurement of 10.3 light years made by Friedrich Wilhelm Bessel is remarkably close to the current accepted value of 11.4 light years. As the stars are separated by 31 arc-seconds the true binary nature was open to question until 1934 when the orbital parameters were accurately measured confirming the true binary status.

The two stars are orange dwarf main sequence stars (K5V, K7V) with magnitudes 5.2 and 6.05 and a combined orbit of 659 years.

Star A is a BY Draconis variable star and B is a flare type variable star with a measured 11.7 year cycle. Both exhibit notable flare activity with B being 25% more active.

Almaach (γ And)

RA 02 04
DEC 42 20

This double star is actually a quadruple system lying at a distance of 355 light years.

Component A is a bright golden yellow giant star (K3IIb) of magnitude 2.2 separated from an indigo-blue companion (magnitude 4.84) by 9.6 arc seconds and position angle 63 degrees.

However, Wilhelm Struve observed B to be a double in 1842 with the components separated by less than an arc-second. Further spectroscopic analysis between 1957 and 1959 revealed a third star.

B is now known to consist of two B9.5V stars (magnitude 5.5) that orbit in 2.67 days and an A0V star (magnitude 6.3). The two B9.5V stars and the A0V orbit in 64 years.

It is possible that fainter surrounding stars also belong to the system.

95 Her

RA 18 02
DEC 21 36

This is a true binary system with an orbit of about 11,000 years lying at a distance of 470 light years and separated by 6.3 arc-seconds.

Component A is a white A5 giant star (magnitude 4.96) with a temperature 0f 8000K a luminosity of 67 Suns, a diameter of 6.8 Suns and a mass of 2.8 solar masses.

B is a yellow-white giant star (G8) with a temperature of 4900K, a diameter of 19.4 Suns and a mass o £.2 solar masses.
A, due to its smaller size, is the more rapid rotator and is in the transition stage between H and He core burning whereas B has already reached the He burning phase.

Delta Cephei

RA 22 29
DEC 58 25

Delta Cephei lies at a distance of 887 light years and is a triple system (possibly quadruple).

It was discovered by John Goodricke in 1784 and its pale orange primary is the prototype for the Cepheid Variables: vital for distance measurements. It is the second closest Cepheid to the Sun (Polaris being the closest) and varies from magnitude 3.5 – 4.4 over a 5.3 day period. Recent radial velocity measurements revealed a spectroscopic companion B with a tenth of the mass of A. This AB system orbits over a 6 year period.

The visual blue companion C is separated from A by an easy 41 arc-seconds and is strongly suspected to also be a spectroscopic binary. Confirmation is needed but would give Delta Cephei the status of a quadruple system.

56 And

RA 01 56
DEC 37 15

56 And lies at a distance of 360 Light Years and can be found on the SW border of the Open Cluster NGC 752 (distance 1,200 Light Years and unrelated to 56 And).

The primary A is a K0 giant star separated from the M0 giant secondary B by 207 arc seconds (PA 298 degrees). Burnham noticed the large proper motion of A and observed a further C star (magnitude 11.9 at 18 arc seconds, PA 77 degrees). In addition, there is a further star D of magnitude 9.77 lying at 204 arc seconds from A (PA 258 degrees).

The present magnitudes of A and B are 5.7 and 5.9 but there has been dispute in the past as to which is the primary in this system implying some magnitude variations and possibly variable-like activity?

However, A and B are not physically connected and are an Optical Double star system.

ɳ Persei

RA 02 51
DEC 55 54

The primary of this multiple star system is a K3 (originally reported as M3?) orange-yellow supergiant (magnitude 3.8) with a luminosity of 13, 000 Suns and an estimated radius of 210 solar radii. Also known as “Miram” it lies at 1, 300 Light years and its light will have undergone significant dust absorption due to its location deep in the Milky Way. It has at least five companions although all are probably line of sight coincidences.

The secondary is a B9 dwarf star of magnitude 8.5 and its blue hue together with the yellow tints of the primary make this a “mini-Albireo”. If this is a true binary system then the orbital period would be a staggering 350,000 years which makes a true binary connection unlikely.

Ʃ 2816

RA 21 39
DEC 57 29

This, at first sight, appears to be a neat triple system found in the heart of the nebulous H11 Open Cluster (IC 1396).
However, things are far more complex and the following systems are now verified:

A (a magnitude 5.73 06F star) and C (magnitude 7.48) are separated by 11.8 arc-seconds (PA 120 degrees)
A and D (magnitude 7.53) are separated by 19.8 arc seconds (POA 338 degrees).
D and E (magnitude 13.19) are separated by 55.2 degrees (PA 351 degrees).
Another B star of magnitude 13.3 was identified by Burnham in 1889 and is separated from A by 1.7 arc-seconds (PA 320 degrees).

Very high resolution observations revealed a further companion to A at a distance 0f 0.1 arc seconds…………..and this is further shown to be a spectroscopic binary making A on its own a very close triple system.

I think that makes Ʃ 2816 a seven-star system……..at least!!

And, close by is the double Ʃ 2819 system consisting of magnitude 7.4, 8.6 stars separated by 13 arc seconds.

A multiple star feast!!!

Beta Cepheus

RA 21 29
DEC 70 34

Beta Cepheus was first observed by William Herschel and Piazzi and is also known by the Arabic name of “Alfirk” meaning Flock of Sheep.

The primary (A: magnitude 3.2) is the prototype of the Beta Cepheid Variable Stars that are similar to the Cepheids but with lower amplitudes and magnitude variations. In this case the magnitude varies from 3.15 to 3.21 over a 4 – 4.567 hour period. It was also itself found to be a binary (a: companion magnitude 8) by speckle interferometry techniques in the 1970s. The Aa system displays an inclined orbit and separations ranging from 0.33 to 0.01 arc seconds. A is a young (50 million years) B3 white/blue giant.

The secondary B is an 8th magnitude A2V star with colours recorded as blue/green. It is separated from A by 14 arc seconds and a position angle between 249 and 251 degrees.

The whole system lies at a distance between 595 and 700 light years according to recent Hipparcos measurements.

λ Ari

RA 01 58
DEC 23 36

First discovered by Christian Mayer and certainly observed by William Herschel Lambda Ari lies at a distance of 129 light years. The angular separation of 37.4 arc seconds has barely changed since Herschel first measured it given an estimated orbital period of 33, 000 years.

The primary is a yellow-white F0 V Main Sequence star with an estimated mass of 1.8 solar masses, a surface temperature of 7200 K, and an apparent magnitude of 4.95.

The secondary is a green-blue G1 V main sequence star with a smaller estimated mass of 1.25 solar masses, a temperature of 5930 K and a magnitude of 7.75.

Also in the field of view are λ Ari C (magnitude 9.7 at a separation of 189 arc seconds from the primary) and λ Ari D (magnitude 9.9 at a separation of 271 arc seconds). These are purely “optical” and are in no way physically related to the main double.

Xi CEP

RA 22 04
DEC 64 38

This is a relatively close double (80 Lyr, 30 pc???) with an orbital period of 3800 years. The spectral designations are A3 and F7/8 with contrasting magnitudes of 4.4 and 6.4. The colours seem to have divided opinion.

Webb found them White and Tawny, Smyth thought them both to be bluish whereas Haas states them to be Lemon-White and Royal-Blue.

17/16 Draconis

RA 16 36
DEC 52 55

17 Dra is a 5.38 B9 dwarf star and a 6.42 A1 dwarf star separated by 3.3 arc-seconds. The combined magnitude is 5.03 with as calculated distance of 412 light years.

16 Dra is a B9.5 Hydrogen-fusing dwarf with a magnitude 5.53 lying at a distance of 423 light years. The motions of the two systems (separated by 90 seconds of arc) are similar so this is a true binary/triple system.

However, 16 Dra is also suspected to be a double with a White Dwarf companion: never seen but revealed by the healthy UV/X-ray radiation measured around the system.

65 UMa

RA 11 55.1
DEC 46 29

Visually this appears to be a neat triple system consisting of a primary star (A) with a close companion (C) 3.7 arc seconds (PA 42 degrees) and a further companion (D) 63.2 arc seconds (PA 114 degrees).

However, this is a seven-star system.

Robert Aitken in 1908 found a star (B) orbiting A at a very close 0.2 arc seconds (PA 329 degrees) over a period of 118 years.
A itself is triple consisting off an eclipsing binary system 0.3 milli arc-seconds apart with a period of 1.7 days. This pair (Aa1 and Aa2) orbits with a third star (Ab) at a separation of 11 miili arc-seconds over a 640 day period. This system is known as DN Uma.

Furthermore, interferometry has revealed D to itself be a double system with a separation of 0.1 arc-seconds.
A fascinating, rare septuple system!!

[/et_pb_text][/et_pb_column][/et_pb_row][/et_pb_section]

Double Star Measurements with a Meade 12mm Astrometric Eyepiece in 2017

Neil Webster, REDACTED

e-mail:     REDACTED

 

Introduction

The following measurements were made throughout 2017 using a Meade 12mm astrometric illuminated reticle eyepiece plus 2.5x powermate attached to a Altair Astro 115mm refractor (focal length 805mm, f7). The total magnification was 167.5x with a field of view of 0.3 degrees.

All final separation values were calculated from a calibration determined by the timing/transit method (Simple Techniques of Measurement: E.T.H. Teague, Chapter 12 in Observing and Measuring Visual Double Stars ed. Argyle, pub. Springer). The final calculated value used was:

12’’.49 +/- 0’’.04 per division on the reticle measuring scale.

Position Angle measurements were made using the method previously outlined in DSSC 25 which involves using the directional west arrow on the handset to electronically steer the primary to the outer edge of the protractor scale rather than turning off the mount motor for an unaided drift. This has proven to be very reliable and greatly increases the number of measures that can be performed during an evening. As previously stated it relies on as precise polar alignment as possible.

10 separation and 10 position angle measurements (N = 20) were performed on the same evening for each pair and the final results and associated uncertainties calculated.

Extensive use was made of the Astroplanner software. Separations throughout the year were limited to a range from 15 arc-seconds to 100 arc-seconds. The faintest magnitude measured was 8.5. These values were out of necessity given the limiting magnification, the high calibration value and the considerable local light pollution. The red light in the eyepiece, even when used at its minimum intensity, also limits the faintest magnitude that can be reasonably measured.

These parameters were set up in the software for whatever constellation was convenient at the date of measurement. All measurements made on any evening were for doubles in close proximity (usually in order of increasing RA) so time was not wasted slewing between distant pairs. This allowed far more measurements to be made than for previous years.

As most of these systems are comparatively wide the orbits are generally very long (1,000 years+) and very few have accurate orbital calculations. Residuals (from the online version of 6th USNO Catalogue of Orbits of Visual Binary Stars) have been given for the few systems calculated but none have a better than grade 4 certainty.

Values from the Fourth Catalogue of Interferometric Measurements have provided a more extensive set of residuals but most of these are from 1991 which is 26 years before the author’s measurements. Although many of the systems have not changed in this time some have and, in certain cases, this shows in the larger residuals calculated.

Where residuals are large (greater than 1o in PA or 1” in separation) relative proper motions have been analysed. Any notable differences between the components’ proper motions that may explain the larger than average residuals are presented in table 4.

Table 5 presents three alternative, more favourable residuals for three systems that have larger than expected residuals.

It should be stressed that these final two tables represent very basic analysis and further professional data and work would be needed to clarify the exact natures and evolving properties of these systems.    

 

References:

The Cambridge Double Star Atlas, (Mullany J. Tirion W. pub. Cambridge)

Observing and Measuring Visual Double Stars (ed. Argyle R.W. pub. Springer)

Washington Double Star Catalogue (Mason, B.D., Wycoff, G.L. & Hartkopf, W.I.):

http://ad.usno.navy.mil/proj/WDS

Sixth Catalogue of Orbits of Visual Binary Stars (Hartkopf, W.I., Mason, B.D. & Worley, C.E.):

http://www.usno.navy.mil/USNO/astrometry/optical-IR-prod/wds/orb6/sixth-catalog-of-orbits-of-visual-binary-stars

Fourth Catalogue of Interferometric Measurements of Binary Stars:

 http://www.usno.navy.mil/USNO/astrometry/optical-IR-prod/wds/int4

Astroplanner:

 http://www.astroplanner.net/

 

Table 1: Measurements

 

Pair Comp RA Dec Va Vb PA (o) +/- Sep (‘’) +/- Epoch

2017 +

N Obs
STTA 254 AB 00013 +6021 7.40 8.33 89.2 0.1 58.0 0.2 0.038 20 WST
STF 3053 AB 00026 +6606 5.96 7.17 69.6 0.1 15.2 0.1 0.665 20 WST
STTA 1 AB 00141 +7601 7.39 7.81 103.3 0.1 73.4 0.3 0.835 20 WST
H 5 17 AB 00369 +3343 4.36 7.08 172.5 0.1 35.7 0.2 0.717 20 WST
HJ 1986 AB 00396 +8445 7.96 8.50 68.7 0.1 40.5 0.2 0.835 20 WST
                         
STTA 5   00400 +7652 6.86 8.78 141.9 0.1 118.3 0.4 0.038 20 WST
H 5 18 AD 00405 +5632 2.35 8.98 282.4 0.1 70.6 0.3 0.038 20 WST
STFA 1 AB

 

00464 +3057 7.25 7.43 46.0 0.1 48.0 0.3 0.717 20 WST
H 582 AB 00474 +5106 7.97 8.35 75.0 0.1 57.2 0.2 0.665 20 WST
HJ 2028 AB 01166 +7402 7.06 7.88 204.1 0.3 61.5 0.1 0.665 20 WST
                         
H 5 12 AB 01579 +2336 4.80 6.65 47.9 0.1 37.2 0.2 0.859 20 WST
STF 222 AB 02109 +3902 6.05 6.71 36.0 0.1 16.6 0.2 0.717 20 WST
S 405 AB 02128 +7941 6.47 7.15 277.3 0.1 55.6 0.3 0.835 20 WST
STF 239 AB 02174 +2845 7.09 7.83 211.6 0.1 13.6 0.1 0.878 20 WST
STTA 26 AB 02197 +6002 6.95 7.30 201.0 0.1 62.7 0.3 0.717 20 WST
                         
STTA 27 AB 02268 +1034 6.72 8.31 31.2 0.1 73.8 0.3 0.900 20 WST
CTT3 AB 02359 +6338 7.78 8.30 88.0 0.1 88.1 0.4 0.717 20 WST
STFA 5 AB 02370 +2439 6.50 7.02 275.1 0.1 37.7 0.2 0.900 20 WST
STTA 28 AB 02390 +6235 6.65 7.56 147.0 0.1 67.8 0.3 0.717 20 WST
HJ 1123 AB 02420 +4248 8.39 8.46 249.7 0.1 20.4 0.2 0.808 20 WST
                         
STT 44 AC 02422 +4242 8.47 8.32 289.9 0.1 87.2 0.3 0.808 20 WST
STF 292 AB 02425 +4016 7.56 8.23 212.3 0.1 23.5 0.2 0.786 20 WST
STF 307 AB 02507 +5554 3.76 8.50 300.5 0.2 30.4 0.3 0.808 20 WST
STTA 31 AB 03009 +5940 7.33 8.03 230.8 0.1 74.2 0.3 0.717 20 WST
STTA 33 AC 03221 +6244 7.73 7.80 111.9 0.1 114.8 0.4 0.134 20 WST
                         
STFA 7 AB 03311 +2744 7.41 7.81 233.9 0.1 44.1 0.2 0.900 20 WST
STT 57 AC 03334 +2322 7.17 7.67 33.1 0.1 68.7 0.1 0.900 20 WST
STF 396 AB 03335 +5846 6.43 7.68 246.0 0.1 20.7 0.2 0.134 20 WST
S 430 AB 03383 +4448 7.21 7.53 96.0 0.1 41.0 0.2 0.808 20 WST
STTA 36 A BC 03400 +6352 6.92 8.27 71.2 0.2 45.8 0.2 0.134 20 WST
                         
STF 434 AB 03440 +3822 7.80 8.28 83.0 0.1 34.0 0.2 0.808 20 WST
S 437 AB C 03463 +2411 8.13 7.70 308.2 0.2 38.8 0.2 0.900 20 WST
STFA 8 BC 03475 +2406 6.27 8.22 345.0 0.1 86.2 0.1 0.900 20 WST
S 436   03493 +5707 6.46 7.17 76.0 0.1 58.3 0.3 0.227 20 WST
STTA 40 AB 03494 +2423 6.58 7.53 309.0 0.1 87.4 0.1 0.900 20 WST
                         
STF 485 AE 04078 +6220 6.91 6.94 305.2 0.1 17.9 0.2 0.227 20 WST
STTA 45 AB 04155 +0611 6.38 7.01 316.0 0.1 63.7 0.1 0.900 20 WST
STTA 44 AB 04173 +4613 7.12 7.99 321.3 0.1 58.6 0.2 0.808 20 WST
SHJ 40 AB 04204 +2721 5.08 7.51 258.8 0.1 48.7 0.1 0.900 20 WST
S 445 AB 04210 +5015 7.31 8.19 328.0 0.1 71.0 0.3 0.808 20 WST
                         
STTA 46 AB 04211 +5532 7.68 7.95 159.8 0.1 99.9 0.1 0.227 20 WST
STF 534 AB 04240 +2418 6.36 7.94 291.0 0.1 29.4 0.2 0.900 20 WST
STF 533 AB 04244 +3419 7.30 8.49 61.2 0.1 20.2 0.2 0.835 20 WST
STF 548   04289 +3022 6.44 8.03 35.0 0.1 14.2 0.2 0.900 20 WST
WEB 2 AD 04327 +5958 5.72 8.45 36.0 0.1 54.6 0.3 0.134 20 WST
                         
S 451   04363 +4722 7.59 7.91 202.0 0.1 55.7 0.3 0.835 20 WST
STTA 53 AB 04374 +0034 7.55 7.57 352.0 0.1 78.8 0.3 0.900 20 WST
OPI 5 AC 04382 +7128 7.67 8.50 279.3 0.1 111.9 0.4 0.227 20 WST
S 455 AB 04422 +2257 4.24 7.02 213.8 0.1 62.5 0.1 0.900 20 WST
S 459 AB 05034 +6027 4.12 7.44 209.1 0.1 84.2 0.3 0.227 20 WST
                         
STF 618 AB 05036 +6305 7.68 7.98 211.0 0.1 33.3 0.3 0.230 20 WST
STFA 13 AB 05061 +5858 5.20 6.21 9.5 0.2 177.7 0.6 0.230 20 WST
STTA 61 AB 05096 +2947 6.72 8.49 245.0 0.1 68.4 0.3 0.347 20 WST
STF 698 AB 05252 +3451 6.65 8.33 347.01 0.1 31.2 0.1 0.367 20 WST
STFA 63   05308 +3950 6.49 7.69 277.0 0.1 75.2 0.3 0.367 20 WST
                         
STTA 72 AC 06247 +5940 7.58 7.58 322.6 0.1 134.5 0.5 0.120 20 WST
S 514 AC 06268 +5825 5.38 7.92 272.0 0.1 94.9 0.4 0.120 20 WST
SHJ 70 AB 06278 +2047 6.65 8.18 201.9 0.1 25.0 0.1 0.271 20 WST
STF 924 AB 06323 +1747 6.31 6.88 211.5 0.2 20.7 0.3 0.271 20 WST
S 524 AB 06341 +2207 7.17 7.41 244.3 0.2 53.0 0.2 0.295 20 WST
                         
STF 994 AB 06595 +3706 7.88 8.14 54.8 0.1 26.4 0.2 0.367 20 WST
HJL 1046 AB 07097 +6045 6.76 7.95 164.0 0.1 184.0 0.6 0.120 20 WST
ES 2624   07219 +4614 8.12 8.25 87.8 0.1 80.9 0.4 0.120 20 WST
STF 1065   07223 +5009 7.51 7.67 254.6 0.2 14.1 0.2 0.120 20 WST
STF 1062 AB 07229 +5517 5.76 6.71 315.2 0.3 15.0 0.2 0.131 20 WST
                         
STTA 84 AB 07254 +5633 7.72 7.75 322.2 0.1 112.8 0.4 0.131 20 WST
STF 1090 AB 07265 +1831 7.27 8.17 98.0 0.1 60.8 0.3 0.295 20 WST
STF 1051 AC 07266 +7305 7.60 7.79 84.0 0.1 31.7 0.2 0.230 20 WST
STTA 87   07389 +4229 7.59 7.78 357.0 0.1 61.4 0.2 0.131 20 WST
STF 1122   07459 +6509 7.78 7.80 184.9 0.1 14.4 0.2 0.230 20 WST
                         
SHJ 86 AB 08025 +6305 6.15 7.53 80.0 0.1 50.7 0.2 0.230 20 WST
STTA 91 AB 08195 +3503 7.26 8.36 209.5 0.1 94.7 0.3 0.131 20 WST
ES 2631   09056 +5018 7.84 8.47 259.0 0.1 78.9 0.4 0.268 20 WST
STF 1315   09128 +6141 7.33 7.65 26.9 0.2 24.9 0.1 0.268 20 WST
STF 1321 AB 09144 +5241 7.79 7.88 97.1 0.1 17.1 0.3 0.268 20 WST
                         
S 598 AB 09287 +4536 5.50 7.80 159.7 0.2 69.7 0.3 0.268 20 WST
STF 1369 AB 09354 +3958 6.98 7.98 149.0 0.1 25.0 0.1 0.134 20 WST
STF 1369 AC 09354 +3958 6.98 8.42 322.9 0.1 116.3 0.4 0.134 20 WST
STF 1369 AC 09354 +3958 6.98 8.42 322.9 0.1 116.3 0.4 0.134 20 WST
STF 1369 BC 09354 +3958 7.98 8.42 324.0 0.1 141.6 0.5 0.134 20 WST
                         
STF 1399   09570 +1946 7.65 8.36 175.9 0.1 30.2 0.2 0.246 20 WST
STF 1415 AB 10178 +7104 6.65 7.27 168.0 0.1 16.6 0.2 0.268 20 WST
HZG8 AC 11045 +3814 6.04 7.56 83.1 0.2 150.1 0.5 0.309 20 WST
S 621 AB 11113 +6601 8.31 8.34 53.4 0.1 102.4 0.5 0.309 20 WST
S 621 AC 11113 +6601 8.31 8.49 314.0 0.1 166.7 0.6 0.309 20 WST
                         
STF 1516 AB 11152 +7329 7.77 8.23 102.9 0.1 67.6 0.3 0.364 20 WST
STF 1540 AB 11268 +0301 6.55 7.50 149.1 0.1 28.1 0.2 0.246 20 WST
STFA 19 AB 11279 +0251 5.05 7.47 182.0 0.1 88.1 0.3 0.246 20 WST
STF 1565   11396 +1900 7.26 8.41 303.9 0.1 22.2 0.1 0.246 20 WST
STTA 112 AB 11545 +1925 8.28 8.49 35.1 0.1 73.9 0.3 0.246 20 WST
                         
SHJ 136   12110 +8143 6.15 8.25 73.7 0.1 71.9 0.3 0.235 20 WST
STF 1625 AB 12162 +8008 7.24 7.78 217.0 0.1 14.2 0.2 0.235 20 WST
STF 1694 AB 12492 +8325 5.29 5.74 324.1 0.1 21.8 0.2 0.235 20 WST
STTA 123 AB 13271 +6444 6.65 7.03 145.1 0.1 69.2 0.3 0.402 20 WST
STTA 127 AB 13510 +6819 6.53 8.32 61.8 0.1 87.4 0.1 0.402 20 WST
                         
STF 1821 AB 14135 +5147 4.53 6.62 235.8 0.1 13.1 0.2 0.298 20 WST
STFA 26 AB 14162 +5122 4.76 7.39 32.0 0.1 329.0 0.2 0.298 20 WST
STF 1850   14286 +2817 7.11 7.56 261.5 0.1 25.1 0.1 0.298 20 WST
SHJ 191   14596 +5352 6.86 7.57 341.0 0.1 40.0 0.1 0.298 20 WST
STF 1972 AB 15292 +8027 6.64 7.30 80.0 0.1 31.8 0.2 0.835 20 WST
                         
STF 1964 AC 15382 +3615 8.07 8.06 86.0 0.1 15.0 0.1 0.298 20 WST
STF 2010 AB 16081 +1703 5.10 6.21 12.0 0.1 27.1 0.2 0.386 20 WST
SHJ 233   16315 +0818 7.07 8.28 70.8 0.1 59.2 0.3 0.402 20 WST
STFA 30 AC 16362 +5255 5.38 5.50 193.3 0.1 90.0 0.3 0.402 20 WST
STFA 30 BC 16362 +5255 6.42 5.50 194.0 0.1 90.1 0.4 0.402 20 WST
                         
STF 2079   16396 +2300 7.56 8.13 90.6 0.1 16.7 0.2 0.386 20 WST
STFA 31 AB 16406 +0413 5.76 6.92 229.0 0.1 69.3 0.4 0.400 20 WST
STTA 149   16435 +2043 7.24 8.38 134.7 0.1 97.4 0.3 0.386 20 WST
S 689 AB 17246 +3913 7.48 8.44 197.0 0.1 89.2 0.4 0.400 20 WST
STFA 35   17322 +5511 4.87 4.90 311.2 0.2 62.1 0.2 0.402 20 WST
                         
STF 2241 AB 17419 +7209 4.60 5.59 15.5 0.1 30.5 0.2 0.402 20 WST
STTA 163 AB 17562 +6237 7.77 7.59 53.0 0.1 54.3 0.3 0.416 20 WST
STF 2259   17590 +3003 7.27 8.44 277.0 0.1 19.5 0.2 0.400 20 WST
STF 2273 AB 17592 +6409 7.31 7.63 283.3 0.2 22.0 0.2 0.416 20 WST
STF 2308 AB 18002 +8000 5.70 6.00 230.2 0.1 18.7 0.3 0.416 20 WST
STF 2278 AB 18029 +5626 7.78 8.14 29.0 0.1 36.3 0.1 0.441 20 WST
STF 2278 AC 18029 +5626 7.78 8.53 38.0 0.1 34.3 0.2 0.441 20 WST
H 5 93   18130 +2815 8.16 8.28 136.0 0.1 54.7 0.2 0.400 20 WST
STF 2323 AC 18239 +5848 5.06 7.95 19.0 0.1 89.1 0.3 0.441 20 WST
STF 2323 BC 18239 +5848 8.07 7.95 19.5 0.1 86.5 0.3 0.441 20 WST
                         
STF 2372 AB 18421 +3445 6.45 7.73 82.0 0.1 25.0 0.1 0.517 20 WST
STFA 38 AD 18448 +3736 4.34 5.62 150.0 0.1 43.7 0.1 0.517 20 WST
STFA 39 AB 18501 +3322 3.63 6.69 148.8 0.1 45.7 0.3 0.517 20 WST
STTA 176 AB 18545 +0154 7.45 7.51 111.7 0.1 94.0 0.4 0.649 20 WST
SHJ 282 AC 18549 +3358 6.14 7.60 349.0 0.1 45.6 0.3 0.517 20 WST
                         
STF 2420 AB 18512 +5923 4.77 8.26 317.0 0.1 37.5 0.1 0.441 20 WST
STF 2474 AB 19091 +3436 6.78 7.88 263.7 0.1 15.5 0.2 0.517 20 WST
STTA 177 AC 19126 +1651 7.11 8.02 276.0 0.1 98.4 0.4 0.654 20 WST
STTA 178   19153 +1505 5.69 7.64 267.9 0.1 89.6 0.3 0.649 20 WST
STTA 181 AB 19201 +2639 7.39 7.50 359.0 0.1 62.8 0.3 0.517 20 WST
                         
STFA 43 AB 19307 +2758 3.19 4.68 54.0 0.1 35.0 0.2 0.550 20 WST
STF 2549 AD 19312 +6319 8.34 8.03 269.7 0.3 55.6 0.3 0.441 20 WST
STFA 44   19332 +6010 6.47 8.19 287.0 0.1 74.9 0.1 0.441 20 WST
ARN 82 AB 19364 +3541 8.10 8.43 34.1 0.1 43.5 0.2 0.564 20 WST
H 626 AB 19373 +1628 5.77 8.35 82.2 0.1 87.4 0.1 0.654 20 WST
                         
STFA 46 AB 19418 +5032 6.00 6.23 132.5 0.1 39.9 0.2 0.564 20 WST
STTA 188 AB 19428 +3741 7.71 7.98 121.0 0.1 61.1 0.2 0.564 20 WST
H 5 137 AB 19459 +3501 6.22 8.18 24.0 0.1 37.7 0.2 0.564 20 WST
STFA 48 AB 19534 +2020 7.14 7.34 147.0 0.1 41.8 0.2 0.649 20 WST
AC 16 AC 19579 +2715 7.81 7.97 136.0 0.1 92.3 0.1 0.649 20 WST
                         
STTA 200 AB 20023 +6438 6.36 8.06 332.3 0.2 99.3 0.4 0.441 20 WST
ES 25 AF 20060 +3546 7.89 6.78 329.0 0.1 95.7 0.4 0.578 20 WST
SHJ 314 AF 20060 +3547 6.78 7.30 28.0 0.1 36.2 0.1 0.578 20 WST
WEB 12 AB 20078 +1950 8.36 8.37 77.0 0.1 40.4 0.2 0.654 20 WST
HJ 606 AB 20084 +3808 7.98 8.12 228.5 0.1 44.0 0.2 0.578 20 WST
                         
STF 2637 AC 20099 +2055 6.56 7.52 221.5 0.1 91.8 0.4 0.654 20 WST
S 738 AB 20106 +3338 7.76 8.43 105.5 0.1 41.3 0.3 0.578 20 WST
STF 2664 AB 20196 +1300 8.07 8.34 321.2 0.1 27.1 0.2 0.654 20 WST
STTA 207 AC 20229 +4259 6.41 8.01 64.6 0.1 85.8 0.3 0.578 20 WST
STF 2687 AB 20264 +5638 6.37 8.31 117.5 0.1 25.5 0.2 0.578 20 WST
                         
STF 2691 AB 20297 +3808 8.14 8.45 31.0 0.1 17.0 0.2 0.578 20 WST
STF 2690 A BC 20312 +1116 7.12 7.39 255.8 0.1 17.7 0.2 0.654 20 WST
STF 2703 AB 20368 +1444 8.35 8.42 289.0 0.1 25.0 0.1 0.654 20 WST
STTA 211 AB 20493 +5845 6.85 7.88 268.0 0.1 95.0 0.3 0.835 20 WST
STF 2758 AB 21069 +3845 5.20 6.05 152.4 0.2 31.8 0.2 0.578 20 WST
                         
BU 69 AC 21026 +2141 8.35 8.02 241.0 0.1 74.6 0.3 0.649 20 WST
STF 2769 AB 21105 +2227 6.65 7.42 299.0 0.1 18.7 0.1 0.649 20WST WST
STFA 56 AB 21377 +0637 6.18 7.50 348.0 0.1 39.0 0.2 0.788 20 WST
GUI 36 CD 21390 +5729 7.48 7.53 324.3 0.1 30.7 0.2 0.835 20 WST
STF 2816 AD 21390 +5729 5.73 7.53 338.9 0.1 20.4 0.2 0.848 20 WST
                         
STT 447 AE 21395 +4144 7.67 8.48 44.3 0.1 28.9 0.2 0.578 20 WST
STTA 222 AB 21441 +0709 7.49 8.47 257.4 0.1 87.4 0.1 0.788 20 WST
ES 382 AC 21509 +3240 8.28 8.42 322.0 0.1 58.3 0.4 0.788 20 WST
STF 2840 AB 21520 +5548 5.64 6.42 196.3 0.1 18.0 0.2 0.846 20 WST
S 800 AB 21538 +6237 7.07 7.91 145.0 0.1 62.5 0.1 0.846 20 WST
                         
STF 2841 A BC 21543 +1943 6.45 7.99 108.0 0.1 22.2 0.2 0.786 20 WST
ARY 45 AB 22083 +6959 7.86 8.11 206.9 0.1 66.6 0.2 0.846 20 WST
STF 2872 A BC 22086 +5917 7.14 7.98 315.0 0.1 22.4 0.1 0.846 20 WST
STF 2893 AB 22129 +7318 6.19 7.91 347.2 0.1 29.2 0.2 0.846 20 WST
STTA 234 AC 22269 +4943 8.15 8.49 133.7 0.1 36.3 0.1 0.657 20 WST
                         
STFA 58 AC 22292 +5825 4.21 6.11 190.8 0.1 40.6 0.2 0.846 20 WST
STF 2922 AB 22359 +3938 5.66 6.29 185.0 0.1 22.4 0.1 0.657 20 WST
STTA 236 AB D 22361 +7253 7.56 8.42 136.0 0.1 42.7 0.2 0.848 20 WST
BU 277 AB D 22395 +4123 8.26 8.50 47.0 0.1 78.1 0.3 0.657 20 WST
HJ 1823 AC 22518 +4119 7.06 8.11 337.5 0.1 81.6 0.3 0.657 20 WST
                         
STTA 238 AB 22527 +6759 7.02 7.58 280.0 0.1 69.2 0.3 0.848 20 WST
STTA 241 AB 22586 +1203 8.28 8.37 160.3 0.1 84.9 0.4 0.788 20 WST
S 825 AB 23100 +3651 7.78 8.26 318.0 0.1 67.1 0.3 0.717 20 WST
STF 2985 AB 23100 +4758 7.21 8.02 256.2 0.1 15.4 0.2 0.717 20 WST
STTA 245 AB C 23260 +2742 7.92 8.50 194.8 0.1 62.5 0.1 0.788 20 WST
                         
SHJ 355 AC 23300 +5833 4.87 7.23 268.6 0.2 74.9 0.1 0.717 20 WST
STF 3041 A BC 23479 +1703 8.35 8.36 358.0 0.1 60.5 0.3 0.786 20 WST
STT 507 AC 23487 +6453 6.76 8.44 349.2 0.1 50.0 0.1 0.717 20 WST
STF 3044 AB 23530 +1155 7.27 7.91 282.5 0.1 18.7 0.1 0.788 20 WST

 

 

Table 2: Residuals from Known Orbits

 

Pair ADS (HIP) Residual (O-C) PA (0) Residual

 (O-C) Sep (‘’)

Orbit Period (yrs)

 

Date Grade
               
STF 1321 AB 7251 -1.4 +0.3 Chang 975 1972 4
STF 1540 AB (55846) +2.3 -0.5 Hopmann 32, 000 1960 5
STF 1821 AB 7173 +0.5 -0.7 Kiyaeva 6, 101 2006 5
STF 1821 AB 7173 +1.0 -1.1 Kiyaeva 6, 675 2006 5
STF 2241 AB 10759 -1.3 +0.9 Kiselev 10, 000 2009 5
               
STF 2308 AB 11061 -1.1 -0.1 Kiselev 18, 000 1996 5
STFA 46 AB 12815 -0.6 +0.1 Marcy 13, 513 1999 4
STF 2758 AB 14636 +0.3 +0.1 PKO 678 2006 4
S 825 AB 16558 -0.7 +0.3 Kiselev 110, 000 2009 5
S 825 AB 16558 -1.8 +0.3 Kiselev 98,000 2009 5
               
S 825 AB 16558 -0.8 -0.1 Kiselev 98,000 2009 5

 

(All Residuals: Observed – latest Catalogue measurement)

 

Table 3: Residuals from Fourth Catalogue of Interferometric Measurements

 

Pair ADS HIP (TYC) Epoch (catalogue) Residual

 PA (0)

Residual

 Sep (‘’)

           
STTA 254 AB BDS 12693 99 1991.61 -0.2 +0.2
STTA 254 AB BDS 12693 99 1991.61 -0.2 +0.2
STF 3053 AB   207 2003.770 -0.6 +0.2
STTA 1 AB   1124 1991.67 -0.2 -0.5
H 5 17 AB 513 2912 2003.804 -0.9 -0.2
           
HJ 1986 AB   (4619 00293) 1991.69 +1.8 +0.1
STFA 1 AB 639 3617 2003.804 -0.3 +0.9
STF 3053 AB   207 2003.770 -0.6 +0.2
STTA 5 BD+76 3145 1991.73 -0.1 +0.6
H 5 18 AD 561 3179 1991.57 +0.5 +1.5
           
H 582 AB BDS 417 3698 1991.76 -0.1 +1.8
HJ 2028 AB   5950 1991.67 +0.4 +0.1
H 5 12 AB 1563 (1757 01964) 2993.918 +0.8 +0.5
STF 222 AB 1683 10176 2003.875 +0.1 +0.1
S 405   10309 1991.73 +0.5 -0.1
           
STF 239 AB 1752 10680 1991.85 +0.1 -0.2
STTA 26 AB   10856 1991.56 +0.7 -0.7
STTA 27 AB   11390 1991.78 -0.7 +0.2
CTT3 AB   12081 1991.66 +0.1 +0.6
STFA 5 AB 1982 12189 1991.70 +0.6 -0.5
           
STTA 28 AB   16218 1991.56 -0.4 +0.0
HJ 1123 AB 2048 (2853 00022) 1991.79 +1.1 +0.3
STT 44 AC 2052 12619 1991.73 -0.1 +0.9
STF 292 AB 2057 12648 1991.70 +0.8 +0.5
STF 307 AB          
           
STTA 31 AB   14049 1991.71 +0.6 +0.6
STTA 33 AC   15686 1991.63 +0.8 -1.4
STFA 7 AB   16386 2004.115 +0.3 +0.8
STT 57 AC 2605 (1798 00480) 1991.57 -0.7 -1.0
STF 396 AB 2592 16587 2004.115 +1.7 +0.6
           
S 430 AB   16972 1991.64 +0.1 -0.1
STTA 36 A BC 2650 17118 1991.66 +0.4 -0.1
STF 434 AB 2717 17424 1991.64 -0.2 +1.0
S 437 AB C 2755 (1800 01961) 1991.64 +0.5 -0.2
STFA 8 BC   (1800 02201) 1991.68 +0.7 +0.8
           
S 436   17858 1991.70 +0.1 -0.1
STTA 40 AB   17862 1991.57 +0.1 +0.5
STF 485 AE 2984 19272 2008.0479 +0.4 +0.1
STTA 45 AB 3085 19859 1991.63 +0.3 -0.7
STTA 44 AB   20000 1991.55 -1.3 +0.3
           
SHJ 40 AB 3137 20250 1991.60 +3.3 -0.4
S 445 AB   20296 1991.56 0.0 -0.8
STTA 46 AB   20306 1991.42 0.0 +0.3
STF 534 AB 3179 20533 2002.901 +0.7 +0.7
STF 533 AB 3185 20570 2002.977 -0.1 +0.6
           
STF 548 AB 3243 20904 2012.6779 -0.9 -0.3
S 451   21437 1991.60 +0.5 -0.4
STTA 53 AB   21534 1991.58 -1.0 +0.8
OPI 5 AC   21578 1991.7 +0.1 +0.1
S 455 AB   21881 1991.56 +0.4 -0.4
           
S 459 AB 3615 23527 1991.64 0.0 +1.1
STF 618 AB   23532 1991.57 -0.4 +0.5
STFA 13 AB   23734 1991.7 +0.5 -1.0
STTA 61 AB   24016 1991.65 +0.5 -0.5
STF 698 AB 4000 25343 2002.884 -0.2 0.0
           
STFA 63   25810 1991.66 +0.8 -0.7
STTA 72 AC   (3776 01181) 1991.63 -0.2 +0.3
S 514 5036 30679 1991.67 0.0 -0.6
SHJ 70 AB 5080 30757 2002.901 -0.5 +0.0
STF 924 AB 5166 31158 2002.91 +0.6 +1.0
           
S 524 AB   31323 1991.85 +0.2 -0.5
STF 994 AB 5642 33649 1991.72 -0.4 -0.4
HJL 1046 5810 34572 1991.68 -1.3 +1.8
ES 2624   35684 1991.85 +0.6 -0.1
STF 1065 6004 35731 1991.86 0.0 -0.8
           
STF 1062 AB 6012 35785 2002.996 -0.5 +0.3
STTA 84 AB   36026 1991.62 -0.7 -0.7
STF 1090 AB 6073 36122 1991.72 -0.1 +0.0
STF 1051 AC 6028 36132 1991.76 +0.4 +0.3
STTA 87   (2966 00032) 1991.76 -0.3 -0.9
           
STF 1122 6319 (4121 01516) 1991.82 -1.3 -0.5
SHJ 86 AB   39340 1991.79 -0.5 -0.2
STTA 91 AB   40791 1991.7 -2.9 +0.8
ES 2631   44628 1991.79 +0.3 -0.5
STF 1315 7226 45206 1991.59 0.0 +0.1
           
STF 1321 7251 45343 1991.81 +6.6 -0.4
S 598   46471 1991.75 -1.4 -2.8
STF 1369 AB 7438 47053 2003.311 -0.9 +0.1
STF 1369 AC 7438 47053 1991.85 0.0 -0.4
STF 1369 BC 7438 47054 1991.86 +0.1 -0.1
           
STF 1399 7589 48785 1991.50 +0.6 -0.3
STF 1415 7705 50433 2003.251 +0.7 +0.1
HZG 8 AC 8046 54136 1991.62 +0.4 -0.2
S 621 AB   54657 1991.72 +1.6 +6.9
S 621 AC   54657 1991.73 +2.1 -4.0
           
STF 1516 AB 8100 54952 1991.77 -0.3 +10.2     (1)
STF 1540 AB   55846 1991.68 -0.6 -0.3
STFA 19 AB   55945 1991.76 +1.9 -1.1
STF 1565   56875 1991.61 -0.5 +0.6
STTA 112 AB  

 

58067 1991.75 -0.4 +0.5
           
SHJ 136   59384 1991.69 -0.7 +1.6
STF 1625 AB 8494 59836 1991.64 -1.4 -0.2
STF 1694 AB 8682 62572 2003.284 -2.2 +0.5
STTA 123 AB   65603 1991.63 -1.5 +0.2
STTA 127 AB   67589 1991.69 -1.1 +2.3
           
STF 1821 AB 9173 69483 2008.278 +0.3 -0.5
STFA 26 AB 9198 69713 2003.251 -0.3 +0.3
STF 1850 9277 79786 1991.71 +0.2 -0.3
SHJ 191 9474 73366 1991.59 -0.8 -0.3
STF 1972 AB 9696 75809 1991.69 +0.8 +0.5
           
STF 1964 AC 9731 76563 2015.400 -0.1 +0.0
STF 2010 AB 9933 79043 2003.418 -1.0 -0.3
SHJ 233   80926 1991.55 +0.1 +0.1
STFA 30 AC 10129   1991.68 -0.1 -0.2
STFA 30 BC 10129   1991.25 Suspect Catalogue Figure?? 0.0         (2)
           
STF 2079 10146 81575 1991.82 +0.1 -0.1
STFA 31 AB 10149 81641 1991.47 -0.4 -0.4
STTA 149   81880 1991.64 +0.3 +0.4
S 689 AB   85201 1991.70 +0.4 -0.5
STFA 35 10628 85829 1999.4 0.0 -0.1
           
STF 2241 AB 10759 86614 1991.7 0.0 +0.3
STTA 163 AB   87815 1991.64 +3.0 -0.4
STF 2259 10955 88055 1991.61 -0.3 -0.2
STF 2273 AB 10985 88071 1991.77 +0.1 +0.7
STF2308 AB 11061 88136 2012.7725 +0.2 -0.8
           
STF 2278 AB 11035 165502 1991.60 +1.0 +0.1
STF 2278 AC 11035 165502 1991.62 +0.9 +0.5
H 5 93   89270 1991.65 +0.1 -0.4
STF 2323 AC 11336 90156 2000.29 -0.5 +0.4
STF 2323 BC 11336 (3916 01982) 1991.41 -1.5 +0.9
           
STF 2372 AB 11593 91707 2003.418 0.0 +0.2
STFA 38 AD 11639 91971 2003.418 -0.3 -0.1
STFA 39 AB 11745 92420 1991.49 -0.6 0.0
STTA 176 AB   92794 1991.81 -0.9 -0.7
SHJ 282 AC 11834 92833 2003.697 -0.4 +0.6
           
STF 2420 AB 1179 92512 2003.628 -2.4 +1.0
STF 2474 AB 12101 94076 2013.5533 +2.0 -0.6
STTA 177 AC 12160 94377 1991.50 -2.5 -3.1
STTA 178   94624 1991.57 +0.9 -0.2
STTA 181 AB   95028 1991.62 -1.3 +1.1
           
STFA 43 AB 12540 95947 2003.418 +0.5 +0.6
STF 2549 AD 12586 96002 1991.76 -1.2 +1.0
STFA 44   96164 1991.63 +0.6 -0.4
ARN 82 AB   (2667 00321) 1991.61 -0.3 +0.2
H 626 AB 12693 96516 1991.69 +0.5 -0.7
           
STFA 46 AB 12815 96895 2003.628 -1.2 +0.8
STTA 188 AB   96986 1991.64 -0.1 +0.8
H 5 137 AB 12900 97242 2003.628 -1.0 -0.5
STFA 48 AB   97876 1991.69 +0.2 -0.3
AC 16 AC 13176 98248 1991.67 +0.2 -1.0
           
STTA 200 AB   98658 1991.73 -0.9 +0.7
ES 25 AF 13376 (2683 03586) 1991.61 -0.2 -0.1
SHJ 314 AF 13374 99002 2003.695 +0.3 +1.5
WEB 12 AB   (1625 00995) 1991.703 +0.2 -0.6
HJ 606 AB   99196 1991.66 +0.3 -0.1
           
STF 2637 AC 13442 99352 1991.65 -0.5 +3.3
S 738 AB 13463 99409 1991.61 -1.6 -0.6
STF 2664 AB   100226 1991.49 -0.3 -0.5
STTA 207 AC 13786 100515 1991.70 +0.3 -1.7
STF 2687 AB 13870 100808 2003.629 +0.2 -0.3
           
STF 2691 AB 13919 101109 1991.68 -0.4 -0.2
STF 2690 A BC 13946 101233 1991.52 +1.0 +0.5
STF 2703 AB   101700 1991.64 -1.1 -0.3
STTA 211 AB   102775 1991.72 +1.7 -2.9
STF 2758 AB 14636 104214 1991.69 +4.4 +1.7     (3)
           
BU 69 AC 14570 103852 1991.44 +0.6 -0.5
STF 2769 AB 14710 104539 2003.784 -0.2 +0.8
STFA 56 AB 15147 106783 2003.629 -0.6 +0.4
GUI 36 CD 15184 106890 2003.620 -0.3 +0.9
STF 2816 AD 15184 106886 2003.620 +0.2 +0.7
           
STT 447 AE 15186 (3191 00346 1991.67 -0.3 0.0
STTA 222 AB   (0555 00887) 1991.88 0.0 -0.2
ES 382 AC 15377 107844 1991.82 -0.2 -0.3
STF 2840 AB 15405 107930 2003.621 +0.6 +0.3
S 800 AB 15434 108073 1991.61 -0.1 +0.0
           
STF 2841 A BC 15431 108119 2003.784 -1.7 +0.2
ARY 45 AB   109275 1991.67 +0.3 +0.0
STF 2872 A BC 15670 (3981 01587) 1991.68 -0.9 +1.2
STF 2893 AB 15764 109659 2003.629 +0.2 +0.4
STTA 234 AC 15951 (3615 00740) 1991.67 -0.2 +0.0
           
STFA 58 AC 15987 110991 2003.629 -0.2 +0.1
STF 2922 AB 16095 111546 2003.625 -0.2 +0.2
STTA 236 AB D 16111 111570 1991.74 -0.8 +0.5
BU 277 AB D 16153 (3209 00191) 1991.63 -0.3 +0.5
HJ 1823 AC 16321 112905 1991.68 +0.2 -0.4
           
STTA 238 AB   112970 1991.72 -0.3 -0.0
STTA 241 AB   11344 1991.66 -0.4 +0.3
S 825 AB 16558 218741 1991.76 -0.5 -0.1
STF 2985 AB 16557 114385 2012.6746 +0.5 -0.4
STTA 245 AB C 16748 115666 1991.64 +0.3 -0.6
           
SHJ 355 AC 16795 115990 1991.59 -0.2 -0.7
STF 3041 A BC 17009 117366 1991.52 +1.6 -1.0
STT 507 AC 17020 117430 2003.629 -1.1 0.0
STF 3044 AB 17079 117768 1991.62 +0.2 -0.5
           

 

 

 

 

 

Table 4: Doubles with significant proper motion differences

 

(All Proper Motions: WDS 2017)

 

Pair Year of C-measurement (O = 2017) RA (primary)             PM (arc-sec/1000yr) DEC (primary)            PM (arc-sec/1000yr)   RA (secondary)             PM (arc-sec/1000yr) DEC (secondary)            PM (arc-sec/1000yr) θ (O-C)

(o)

ρ   (O-C)

(‘’)

                 
HJ 1986 AB 1991 +050 +021   +079 -024 +1.8 +0.1
H 5 18 AD 1991 +051 -032   -002 -003 +0.5 +1.5
H 5 82 AB 1991 -026 -024   +017 +004 -0.1 +1.8
SHJ 40 AB 1991 -029 -078   -001 -001 +3.3 -0.4
S 459 AB 1991 -006 -015   -014 -035 0.0 +1.1
                 
STFA 13 AB 1991 -007 -008   -004 -027 +0.5 -1.0
HJL 1046 AB 1991 -009 -048   -013 -058 -1.3 +1.8
STTA 91 AB 1991 -055 -005   +088 -139 -2.9 +0.8
STF 1321 AB 1991 -153 -056   -155 -066 +6.6 -0.4
S 598 1991 -022 -012   -090 -016 -1.4 -2.8
                 
S 621 AB 1991 -334 -124   +007 -002 +1.6 +6.9
S 621 AC 1991 -334 -124   +000 -001 +2.1 -4.0
STF 1516 AB 1991 -402 +110   +001 -002 -0.3 +10.2
STFA 19 AB 1991 +016 -010   -090 +017 +1.9 -1.1
STTA 127 AB 1991 -176 -058   -104 +011 -1.1 +2.3
                 
STF 2010 AB 2003 -034 -006   -026 -032 -1.0 -0.3
STTA 163 AB 1991 -053 +099   +011 -014 +3.0 -0.4
STF 2278 AB 1991 -021 +039   +004 +013 +1.0 +0.1
                 
STF 2278 AC 1991 -021 +039   +001 +012 +0.9 +0.5
STF 2420 AB 2003 +078 +025   +000 +000 -2.4 +1.0
                 
STTA 177 AC 1991 +002 -012   +125 -196 -2.5 -3.1
STTA 181 AB 1991 +013 -053   -021 +010 -1.3 +1.1
STF 2549 AD 1991 +041 +020   -006 -009 -1.2 +0.2
STF 2637 AC 1991 +059 +098   +005 -056 -0.5 +3.3
STF 2637 AC 1991 +059 +098   +005 -056 -0.5 +3.3
                 
S 738 AB 1991 -011 -017   +001 +001 -1.6 -0.6
STTA 207 AC 1991 +056 +043   -003 -018 +0.3 -1.7
STTA 211 AB 1991 -004 -002   +131 +100 +1.7 -2.9
STF 3041 A BC 1991 +017 -010   +083 -078 +1.6 -1.0

 

Table 5: Alternative Residuals

 

 

  CATALOGUE (date) Residual (O-C)                  PA (o) Residual (O-C) SEPARATION (“)
       
STF 1516 AB (1) Fourth Interferometric (1991) -0.3 +10.2
STF 1516 AB (1) WDS (2015) -1.1 0.0

 

       
STFA 30 BC (2)

 

Fourth Interferometric (1991) * 0.0
STFA 30 BC (2) WDS (2015) -3.0 -1.4

 

       
STF 2758 AB (3) Fourth Interferometric (1991) +4.4 +1.7
STF 2758 AB (3) WDS (2016) +0.2 +0.4

 

 

*Fourth Interferometric Catalogue gives a PA of 15.5 degrees?? WDS (2015) gives 197 degrees and NW measured 194 degrees.

 

Double Star Measurements with an Astrometric Eyepiece in 2016

[et_pb_section bb_built="1"][et_pb_row][et_pb_column type="4_4"][et_pb_text _builder_version="3.12"]

Neil Webster, REDACTED
E-mail : REDACTED

Introduction

The following measurements were made with a Meade 12-mm astrometric illuminated reticule eyepiece attached to a recently purchased Altair Astro 115-mm refractor (focal length 805mm, f7). The optical train also employed a 2.5x Powermate to give a total magnification of 167.5x. Calibration was achieved over two evenings using the timing transit method as outlined in Teague1 Three separate stars were used and the results (reassuringly close) averaged to give a calibration of: 12".49 ± 0".4 per division on the measuring scale.

Method

Earlier attempts with a smaller scope (SIV 80-mm APO) had indicated the necessity of taking multiple readings to achieve a credible result. Unless stated, each system has 10 separation and 10 position angle measurements (N 20) from which a final result and associated uncertainty were calculated. As expected the later results were, overall, found to be closer to \VDS values especially in P.A. Early P.A. values were made by turning the motor off and allowing the primary to drift and cross the, outer protractor scale. The scope was moved manually in R.A. to allow further measurements to be made. However, even with a relatively small system this was not easy and the following method was adopted:

With the motor on, the two stars were positioned parallel to the measurement-axis with the primary positioned to pass through the centre-point. The system was then steered to the outer scale using the R.A. control on the handset. The value that the primary passed through was noted and the appropriate conversion to the correct P.A. value made afterwards.
This has the advantage that repeated measurements can be, easily made and the scope can be easily slewed to the next system afterwards. The PA results were seen to immediately improve using this method. It, of course, relics on precise polar alignment of the mount so movement in declination is at an absolute minimum.

Duc to the small magnification of the, system the limiting useful minimum separation measurement is about 14" . The accuracy of PA for small separations is also harder to achieve especially if the secondary is very faint. The faintest magnitude used for measurement was 10.3 due partly to local light pollution but also due to the obscuring rcd light used to illuminate the measuring eyepiece.

As most of these systems arc comparatively wide the orbits are, generally very long (30,000 years ) and very few have accurate orbital calculations. Residuals (from the online version of 6th USNO Catalogue of Orbits of Visual Binary Stars) have been given for the few systems calculated.

Residuals from the Fourth Catalogue of Interferometric Measurements have provided a more extensive set of residuals.

References

(1) Teague, E. T. H. (2012) in Argyle, R. W. (ed.), Observing and Measuring Visual Double Stars, Springer
(2) The Cambridge Double Star Atlas, (Mullany J. Tirion pub. Cambridge)
(3) Washington Double, Star Catalogue (Mason, B.D., Wy-coff, G.L. Hartkopf, w.l.):
51
(4) http : // ad. usno . navy .mi1/proj/WDS
(5) Sixth Catalogue of Orbits of Visual Binary Stars (Hartkopf, NV.I., Mason, B.D. & Worley,
http : / /www.usno . navy . mil/USNO/astrometry/optical- IR-prod/wds/orb6/sixth- catalog-of-orbits-o (6) Fourth Catalogue of Interferometric Measurements of Binary Stars:
http : //www.usno . navy. mil/USN0/ astrometry/ optical-IR-prod/wds/int4

[/et_pb_text][et_pb_text admin_label="Full Report" _builder_version="3.12"]

Full Report and tables of results

NW Webb 2016 Report

[/et_pb_text][/et_pb_column][/et_pb_row][/et_pb_section]

TOP
Protected by CleanTalk Anti-Spam