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 13th May 2021 at 7.30 p.m. "Observing with Binoculars" presented by Mark Radice, Salisbury

This talk endeavours to encourage binocular observations - either in their own right or to supplement telescopic and imaging projects. It will explain why we should all have a pair of binoculars in our observing kit and will describe what can be seen with a simple pair of binoculars, techniques to use them to best effect and some of the more interesting objects made under the night sky.

Our speaker:

Mark Radice is an amateur astronomer and photographer based near Salisbury, Wiltshire with a passion for observing the night sky.

He started actively observing using a borrowed pair of binoculars when comet Hyakutake crossed the sky in 1996 and now enjoys using his own equipment from a garden observatory.

Astronomical interests include high resolution lunar and planetary imaging, deep sky sketching and binocular observing - all with a cup of tea.

He writes occasionally for Astronomy Now, enjoys visiting dark skies and star parties in the UK and overseas and writes too infrequently on his own blog.


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

Brecon Dark Skies Status

The Brecon Beacons National Park is the closest International Dark Sky Reserve to us here in south Wales. To maintain the status of the park they need your help. There is a consultation process for the new management plan in which your voices will be considered as important in maintaining the dark sky status. Please write in using the following email address:
You can mention how you enjoy the national park, why dark skies are important for conservation, environment protection, mental health, conservation of wildlife and the historical heritage of the night sky. Just make it personal. Your voice makes a huge difference. Thank you everyone!

FAS Dark Skies Position Statement

Please click on the button to the right to download the recently issued statement from the Federation of Astronomical Societies regarding their views on dark skies and light pollution.

The statement mentions two other sources of information

  • Information on the All-Party Parliamentary Group for Dark Skies 2020 policy paper on Ten Dark Sky policies for the government can be found here
  • Information on the model followed by the UK Dark Skies Matter initiative can be found here

CAS Social on Tuesday Evenings via Zoom (Members Only)

Every Tuesday evening from 7pm to around 8:30 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

  • NEW:Register for a free, online talk "William Herschel - Discoverer of the Deep Sky - The epochal work of the greatest visual observer and his talented sister Caroline" on Jun 19 2021 19:30 - 21:30 which has been organised by Wells and Mendip Astronomers supported by Bath Astronomers. Further details and tickets available here
  • NEW: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
  • 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
  • Book tickets for free, online Astronomy talks being run by Royal Observatory Edinburgh. See here
  • Catch the very latest astronomy news from See here
  • Buy the recently published book The Search for Life on Mars: The Greatest Scientific Detective Story of All Time by Elizabeth Howell and Nicholas Booth - see here
  • Watch video: 10 Unsettling Astronomical Incidents and Phenomena - see here
  • Watch the eighth series of How the Universe Works on the Discovery Channel - now being rebroadcast. Series 1 to 7 also available
  • Watch a video of a talk given to the Society for Popular Astronomy - this 77 minutes talk, being shown with the kind permission of the SPA, is by Dr Rene Breton and is entitled Einstein's Relativity: Tested to the Limit with Pulsars
  • Join the Virtual Astronomy Club
  • NASA At Home provide a range of activities - details here. Or watch NASA TV
  • Astronomy Citizen Science Projects - see here
  • The Sky at Night - and watch old and not-so-old episodes on the BBC iPlayer including the 800th episode shown on BBC4 on 10th May 2020!
  • Astrophotography with only a DSLR camera or a smartphone - see here and also here
  • Podcasts - for instance, the BBC Sounds podcast includes The Life Scientific series which features a number of astronomy-related sessions including an interesting interview with Dame Jocelyn Bell Burnell who, scandalously, was not awarded a Nobel Prize after her discovery of radio pulsars
  • 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