Astronomy Every Thursday…



Face-to-Face Meetings Every Thursday

Face to face meetings every Thursday plus we are live on Zoom*

As a courtesy to others please stay at home  and attend via the zoom if  you are feeling unwell – coughs, sniffs and sneezes etc.

* zoom will only be available with the lecturer’s consent.


A selection of images, photos and observations taken by CMHASD members


Society News

AstroFest 2024

Many members have been at AstroFest this weekend, but it looks like the cost of living crisis and high prices seem to be having an impact, with many retailers and manufacturers not exhibiting at AstroFest this year. At least there isn’t the crush of people from past years and a bit more space to have a coffee and cake or get get some practice in docking to the ISS.

Occultation of Asteroid 2000 SZ278

Observation of an occultation by Asteroid 2000 SZ278 using an eVscope by Mike Rushton.
Mike has just started analysing these himself rather than sending them off to California for a bot to do the work.
Asteroid 2000 SZ278 which is a Main Belt member and only 1.2km in diameter passed in front of a 13th Mag star. The shadow crossed Kent and blocked the stars light for 2.2 secs.
You can clearly see this in the light curve (The time series data are 0.3 secs apart.)

Occultation by Asteroid 2000 SZ278 on 2024-01-26

The Moon – 17th Dec 2023

A lovely image of a Waxing Crescent Moon taken on the 17th Dec 2023 by member Honor Wheeler. On this day the Moon was 4.72 days old, 27.01% illuminated and in the constellation Aquarius.

The image was taken using a Skywatcher ED80 Refractor, Skywatcher EQ3 Synscan mount, x2 Barlow, Canon M6 MRKII Camera set at ISO100 and exp. 1/20s.

CMHASD Christmas Quiz – 2023

Congratulations to team Dalek for winning this years CMHASD Christmas Quiz.   

Team Dalek

Member’s Rita Whiting and Debra Holton pulled out all the stops to provide a night of head scratching, puzzlement and fun.  Thank you Rita & Debra for all your hard work & effort creating the quiz.  It was a great night and we are all looking forward to the next one!

The Moon – 19th Dec 2023

A stunning 10 frame image of the Moon taken by member Neil Webster on the 19th Dec 2023.  The Moon was in the First Quarter phase, 47% illuminated, 7.07 days old and in the constellation Pisces.

The First Quarter phase comes roughly 7 days after the New Moon and is when the moon has completed one quarter of its orbit around the Earth hence the name First Quarter.  The Moon in this phase is also referred to as a Half Moon too.

Neil acquired is image using a R/IR filter, ZWO ASI 290MM, EQ6 R, AA 115 triplet APO, and Firecapture. 10 frames stitched in Microsoft ICE. Each 90s x 33fps. 20% stacked in AutoStakkert. Post processed in Photoshop.

MOON Dec 19th 2023 7.07D 47% First Quarter

Below are a couple of individual frames from the above image.

To see more of Neil’s brilliant images check out his flickr page at https://www.flickr.com/photos/137388222@N05/with/53409456667/

Venus, Spica & Moon – 8th Dec 2023

Two super images by member Jim Burchell taken on the 8th Dec 2023. The 1st image shows Venus, the star Spica and the Moon going lower left to top right.  Spica is the brightest star in the constellation of Virgo and one of the 20 brightest stars in the night sky. The 2nd image is of the Moon with Earthshine.

The Moon on the 8th December 2023 was 24.88 days old, 22.05% illuminated and in the Waning Crescent phase. This is the phase where the moon is less than 50% illuminated but has not yet reached 0% illumination which would be a New Moon.

Jupiter using a red filter – 5th Dec 2023

A great image of Jupiter taken by member and trustee Simon Dawes.

The image was taken on the 5th Dec 2023 using a Celestron EDGE11HD, with a red filter, f2800mm (f10), Rising Cam CMOS sensor and Mesu e200 mount. Sharpcap Pro, 2 min of video, stacked in AutoStakkert, processed in Registax 6 and Photoshop.

For more member images of Jupiter check out the Jupiter section on our website.

For more information about using filters for visual observing of the Moon and planets https://britastro.org/2018/filters-for-visual-observing-of-the-moon-and-planets

Moon – 28th Nov 2023

Two lovely images of the Moon taken by members Jim Burchell & Kevin Langford on the 28th Nov 2023.  The Moon was in it’s Waning Gibbous phase.

On this day, the moon was 14.57 days old, 99.58% illuminated and so in the Waning Gibbous phase and found in the constellation Gemini. The Waning Gibbous phase is the first phase after the Full Moon.  It lasts roughly 7 days with the Moon’s illumination growing smaller each day until the Moon becomes a Last Quarter Moon with an illumination of 50%, sometimes referred to has a half moon.

Gibbous has its origins in the Late Latin word gibbosus, meaning ‘humpbacked’ and the Latin word gibbus, meaning “hump.” It was adopted into Middle English to describe rounded, convex things.

Kevin Langford’s image taken using a Cannon 750D and a 150 to 600 mm Sigma lens.

Jim Burchell’s image taken using a Pentax KP,  F8.0, 1/400 sec, 300mm, iso 800 and cropped in Snapseed.

Lunar Halo – 25th Nov 2023

A stunning example of a Lunar Halo captured by 3 members of the society – Leigh Slomer, Honor Wheeler and Simon Dawes on the evening of the 25th Nov 2023.  The white dot at the 4 o’clock position from the Moon is the planet Jupiter.

The ring around the Moon – or ‘lunar halo’ is caused by the refraction of moonlight from ice crystals in the upper atmosphere. For more information check out https://atoptics.co.uk/blog/moon-halo/

Leigh Slomer


Honor Wheeler


Simon Dawes


The Sun by Jim Burchell – 23rd Nov 2023

NEVER LOOK AT THE SUN DIRECTLY. Please click here for solar observing safely.
A superb single image of the Sun in white light showing sunspot groups 3489-3498 taken on the  23/11/2023 by member Jim Burchell.
The image was taken with a Pentax KP body attached to 102mm Altair Astro refractor fitted with a solar filter (baader solar film) then processed in Snapseed.  Jim said that seeing wasn’t particularly good and it was also quite windy.

Shears Green Junior School – Cosmic Camp 2023

Several society members attended Shears Green Junior School on Friday 15th September 2023 with their own or a society telescope to take part in the school’s ‘Cosmic Camp’.  The Society would like to say a big thank you to all the members who helped make this event a success.

Member Diane Clarke who attended the event wrote ”Earlier in the year the CMHASD was again invited to the Shears Green Junior School Cosmic Camp.  So we took our telescopes along to offer views of various stella sights.

In the evening Jupiter & 3 of its Galilean moons appeared above the horizon and was again greeted with awe & wonder by all who viewed them. There was also views of Cygnus & the planet Saturn with its largest moon Triton.

The double star Mizar (Alcor) in Ursa Major also proved a great hit when the children discovered that 1 star was actually 2 stars.

As well as showing the children the night sky we also had some classroom presentations and a display of members images along with an image from the JWST on show.    

The members who went along had an extremely enjoyable and rewarding time due to the enthusiasm of all the children & teachers at the camp.  Lots of questions were asked by a very inquisitive & enthusiastic young audience and as they looked through the telescopes we heard were phrases such as “wow”, “is that real?” & “is it a hologram?”

One of the teachers from the school wrote in a thank you email to us “We all had such a fantastic time last Friday and the children didn’t stop talking about it for days.”

We look forward to next year 🙂”

The Society did not take any photos of the event as there were too many safeguarding issues.

Comet Lemmon C/2023 H2 – Nov 2023

Superb image of Comet Lemmon C/2023 H2 taken by member Richard Bohner on the 11th Nov 2023 from Arizona, USA. Richard used the following to acquire his image – Canon 5D Mk IV on a Celestron 8” SCT. Magnification about 100X. 60 seconds exp. At ISO 10K.

The comet was discovered on April 23, 2023 with a robotic 1.5m reflector telescope of the Mount Lemmon Survey, hence the name Comet Lemmon (C/2023 H2). That program is part of the Catalina Sky Survey based at Stewart Observatory’s Catalina Station near Tucson, Arizona, which combs the sky each night in search of new comets and asteroids. The comet is just one of an incredible 50,000 asteroids and comets discovered by the Mount Lemmon Survey, making it one of the most prolific minor planet-discovering surveys currently operating.

During mid-November the comet was moving across the western sky from the constellation Hercules through Aquila just below the Summer Triangle asterism.

More ExoPlanet transits for the ExoClock Project – Nov 2023

Five more transits done!

TOI-3688 A b is a gas giant exoplanet that orbits a G-type star. Its mass is 0.98 Jupiters, it takes 3.2 days to complete one orbit of its star and is 0.0456 AU from its star. Its discovery was announced in 2023.


Exoplanet GPX-1 b is in the constellation of Perseus. GPX-1 b is a gas giant exoplanet that orbits an F-type star. Its mass is 19.7 Jupiters, it takes 1.7 days to complete one orbit of its star and is 0.0338 AU from its star. Its discovery was announced in 2021.

Exoplanet Qatar-5b is located in the Andromeda constellation.  Qatar-5 b is a gas giant exoplanet that orbits a G-type star. Its mass is 4.32 Jupiters, it takes 2.9 days to complete one orbit of its star and is 0.04127 AU from its star. Its discovery was announced in 2017.


Congratulations to Dave Grist & Steve Floodgate

A huge congratulations to CMHASD members Dave Grist and Steve Floodgate for receiving the BAA Horace Dall medal & gift this year.  Chairman John Archer wrote ”For anyone who travelled up to the Institute of Physics last Saturday or tuned in via Zoom for...

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Sundogs & 22-degree Halo by Jim Burchell

Fine examples of sundogs and part of a 22-degree halo captured by member Jim Buchell on the 25th September 2023 from Dartford. ”A sundog, also known as sun dog, mock sun or parhelion, consists of glowing spots around the sun. They are created by sunlight...

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ExoClock Conference, Thessaloniki, Greece 2023

2023 October 21/22 Aristotle University of Thessaloniki, Greece  3rd ExoClock Annual Meeting  CMHASD trustees Martin Crow, Simon Dawes and Dr Mike Rushton attended the 3rd Annual Conference of ExoClock in Greece, a project to improve the ephemeris of...

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ExoPlanet transit of HAT-P-23b by Keith Rickard

One more for the ExoClock project – this one being the first for CMHASD trustee and treasurer Keith Rickard.  It is of Exoplanet HAT-P-23b in the constellation Delphinus. ”HAT-P-23 b is a gas giant exoplanet that orbits a G-type star. Its mass is 2.09...

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Superb Sun Pillar imaged by John Archer

Whilst travelling early morning on a train to London, CMHASD Chairman John Archer saw this fine example of a sun pillar on the 23rd October 2023.  ”Sun pillars and light pillars are beams of light that extend vertically upward (or downward) from a bright...

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Comet C/2023 P1 (Nishimura) imaged by Martin Crow

C/2023 P1 (Nishimura) is a long-period comet discovered by Hideo Nishimura on 12 August 2023 and member Martin Crow imaged it on the 20th August 2023.  At the time of its discovery, the comet was in the constellation of Gemini and shining at magnitude +10.4....

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ExoPlanet TrES-3b transit – observed by Simon Dawes

Another for the ExoClock project by Simon Dawes of the transit of exoplanet TrES-3b. TrES-3b is in a very tight orbit around its host star, TrES-3, transiting the stellar disk once per 31 hours. For comparison, Mercury orbits the sun once every 88 days. TrES-3b is...

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