Next Talk

Please note that all talks until at least July 2021 will be held on the Zoom video conferencing platform. Invitations to Zoom talks are sent to CAS members shortly in advance. Members planning to watch a talk should try to enter the Society's Zoom "Waiting Room" before 7.30 p.m., as late entry may be distracting for everyone.
The resumption of talks within a lecture theatre environment will be clearly announced.

Thursday 2nd September 2021 at 7.30 p.m. "Exploring Astronomy through Philately" presented by Katrin Raynor-Evans, FRAS, FRGS

The first astronomy themed stamp dates to 1887 when Brazil issued a perforated stamp, buff and blue in colour, depicting the Southern Cross, an asterism seen in the southern hemisphere. Even throughout the 1800's, stamps were being printed with astronomical watermarks, such as suns and stars and early stamps issued in Egypt were designed with a pyramid and star. Over the decades, we have celebrated astronomy and space on stamps including comets, man on the moon and events in the astronomical calendar such as solar eclipses. Exploring Astronomy and Space Through Philately will take you on an out of this world journey looking at and discussing a selection of astronomy and space themed stamps that have been issued all over the world, proving that we can enjoy the wonders of the universe even on a cloudy night.

Our speaker:

Katrin Raynor-Evans is a Fellow of the Royal Astronomical Society and Royal Geographical Society. She is a member of the European Astronomical Society and Astro Space Stamp Society. She writes articles and interviews for popular astronomy magazines including the BBC Sky at Night, Astronomy, Stanley Gibbons and has a regular weekly column 'Thematic Thursday' for All About Stamps. She is co-authoring her first book and volunteers as a Program Producer for Astro Radio. Recently asteroid 446500 Katrinraynor was named after her.


The Society's activities during the coronavirus (COVID-19) pandemic


During the coronavirus crisis the Society wishes to ensure that the risks to CAS members and the wider public are minimised. Accordingly, please note that:

  • we currently expect that all the fortnightly talks in the 2020/21 season will need to be held using the Zoom video conferencing platform (see the guidance below); and
  • no CAS Star Parties at our Observatory at Dyffryn Gardens are currently planned, and the Observatory is closed until further notice.

We will keep members updated on future developments via this website and other suitable means. We hope everyone stays well during the crisis.

GUIDANCE ON ZOOM: See this short video on how to join a Zoom meeting and this specific CAS guidance

2021/2022 Talks

The speaker programme is now confirmed from September 2021 up to March 2022. The remainder of the programme is ready in draft form and we will update the programme as talks are confirmed. We are awaiting further clarification from the University about the availability of the lecture theatre and we will keep you informed as soon as we hear anything.

Please click on the button to the right to access the 2021/22 Talks.

New for Junior members

One of our junior members has started writing a blog about a variety of astronomical topics. Why not have a read? Note: You don't have to be a junior to read it!

Find the link on our Junior Page which you can access here

GoSpaceWatch is Hosting a series of talks throughout August

The Universe: Half an Hour at a Time. Have you ever wondered how the universe began, how it will end, and everything in between? Maybe you do not have the time to read the many fantastic astronomy books on the subject, or you think that they might be too technical for you to understand.

This summer, GoSpaceWatch, with Dr Steve Barrett from the University of Liverpool, presents a series of online talks designed to encompass some of the popular questions about the universe. Four talks, each taking just half an hour, over four weeks, and aimed to give the enquiring mind a better understanding of our current knowledge of our universe.

This special Zoom series is free to attend after registration. Open to all, from beginners to those who already know a little astronomy. Register once to attend all four talks.

Free Registration via Eventbrite here


Mike Disney blog

Professor Mike Disney (CAS Vice-President), who many of you will know from previous talks he has given us, has started a blog called "Thinking For Ourselves". Topics include Astronomy (of course!) and also his thoughts on the Scientific Method and Thinking for Ourselves, which is the title of his latest book. If you want to find out more about his book then see here.

The link to his blog can be found by clicking on the button to the right.

CAS Previous speakers news

Two previous Cardiff Astronomical Society speakers have just been elected to prestigious roles in science here in the UK. Professor Mike Edmunds (CAS Vice-President) has been named president of the Royal Astronomical Society (see details here) and Professor Bernard Schutz has been made a fellow of the Royal Society (details here). You can listen to them both being interviewed by Chris North, who is also a previous speaker to CAS, on the latest Pythagorean Astronomy podcast, where they talk about the history of both societies and the future of astronomy. The podcast can be found on Spotify here

CAS Social on Tuesday Evenings via Zoom (Members Only): Restarting in September

Alternate Tuesday evenings (in the same week as a Society Talk) from 19:30 to around 21:00 we hold a social get together on zoom where we chat about both astronomical and non-astronomical subjects, have a quiz and have presentations by members. These presentations are usually on either member's hobbies or their travels but can be on anything they think others will find interesting.
Why not come along one week to see what you think. You do not need to stay for the whole session and people often arrive late or leave early because of other commitments. It is very informal!
To register your interest email please include your Membership Number and you will be sent a link to the next session.

Possible things to do during the lockdown or in self-isolation

  • Enrol on one of the free talks being run by The Geological Society of London about the Geology of Space. For more details see here
  • Browse or subscribe to a new blog the Hellas Daily Herald, a daily digest of news on Mars science and exploration. Details here
  • Listen to this Radio 4 programme on Gravity with Hannah Fry and Adam Rutherford See here. BBC Sounds podcast here. Also on Acast and probably iTunes.
  • Listen to the talks run by Palomar Observatory See here. The times given are Pacific Time but you can view the talks at any point afterwards on YouTube.
  • Listen to The Infinite Monkey Cage Podcast. A recent episode is on The Night Sky and Tim Peake is a guest. Listen here
  • NASA At Home provide a range of activities - details here. Or watch NASA TV
  • Astronomy Citizen Science Projects - see here
  • The Sky at Night - watch old and not-so-old episodes on the BBC iPlayer
  • Astrophotography with only a DSLR camera or a smartphone - see here and also here
  • Fine-tune and clean your astronomy equipment - guidance is available on the internet including in the BBC's online Sky at Night magazine

The night sky this month

(Courtesy of BBC Sky at Night Magazine)

Day-by-day guide to this month's night sky

- text and photos


Next Star Party



Next Observing Session




Introduction to CAS

The Cardiff Astronomical Society (CAS) is a thriving society located in South East Wales. It has been in existence for over 40 years and is one of the largest amateur astronomical societies in the UK. CAS provides a range of facilities for both Society members and the public at large including a varied programme of talks on Thursday evenings (except in August) at the Physics and Astronomy Department of Cardiff University. In addition, regular night sky (and occasional solar) Observing Sessions are held at the Society's own Observatory at Dyffryn Gardens.

Our members come from all walks of life and their knowledge of astronomy ranges from complete beginner to advanced. You don't need any specialist knowledge to join us and neither do you need to own a telescope or binoculars. It's also possible to try us out before joining!

More details about the Society and what it does are available here

We are keen to get more Society members on board to assist with the running of CAS events - please see here how you can Help Us


Come and join some of the Society's 275 members at one of our talks or observing events. We promise a warm and friendly welcome for all. Only £15.00 per annum also means you can make use of our Library

Gift Aid

CAS is registered for Gift Aid. This means that, if you are a UK taxpayer, we can claim back the standard rate tax on subscriptions (and on any donations) giving an effective 25% boost to the amount the Society has received. However, in order to reclaim these monies from HMRC, we need all members who pay tax to complete and return a Charity Gift Aid Declaration form. Please note that if you have paid your subscriptions by PayPal, you will have already been asked if you would consent to those subscriptions being Gift Aided - but we still need a completed Charity Gift Aid Declaration form in order for us to reclaim the tax paid as Gift Aid.

If you are eligible, please take a form (using the button opposite) and then complete it and pass it to us at one of the fortnightly talks or send it to CAS by post or email (see the bottom of the form). Thank you for your help!

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Society help for schools etc



As shown here, Cardiff Astronomical Society welcomes all invitations from organisations such as colleges, schools and guide/scout/brownie groups located in Cardiff and surrounding areas for an outreach stargazing/astronomical event for all ages and levels of knowledge. Society members very much enjoy bringing our passion for the subject to a wider audience and helping everyone to get started in this fascinating subject. We do not charge a fee for our expertise and participation; the enjoyment is enough reward and we will do our very best to ensure a worthwhile and enthralling evening. We would, however, be grateful for reimbursement of travelling expenses and petrol costs to venues outside of Cardiff and its environs. Otherwise the cost would fall on individuals and the non-profit-making Society. It should be noted that CAS has a formal Policy on Child Protection and the Protection of Vulnerable Adults


Black Lives Matter in Astronomy

See this update from the Royal Astronomical Society