From the President: A penumbral lunar eclipse, and BAA ‘Observer’s Challenges’

2017 March 20

Jeremy Shears

The recent evening elongation of Venus has attracted much public attention. I lost count of the number of times that people asked me about the bright object in the sky at sunset. Most were amazed to learn that it was Venus – even more so when I was able to show them the Moon-like phase through the telescope. Many observations of Venus have been sent in by observers and Richard McKim has written a summary of some of these in this edition of the Journal.
Another observing opportunity was February’s penumbral lunar eclipse. Often overlooked in favour of ‘proper’ eclipses, this one also received public attention and was mentioned on the BBC TV and radio. We decided to issue an ‘Observer’s Challenge’ via the BAA website to encourage people to go outside to observe it. What made this penumbral eclipse special was that virtually the whole of the Moon’s face passed within the Earth’s penumbra, so the reduction of the Moon’s brightness was more perceptible than usual for a penumbral eclipse. Although much of the country was cloudy, many people did spot the eclipse, with several commenting on their surprise at how obvious the dimming was. Alan Tough and Denis Buczynski were able to obtain some images from Scotland, shown here.
There have recently been some fine conjunctions involving the Moon, Venus, Mars and Uranus in the western sky. Responding to another Observer’s Challenge, Richard J. Coles recorded the conjunction of the Moon, Venus and Mars in a beautiful evening scene in early March from Perthshire. Several other members submitted images of the conjunction to their Members Page – and some of these included Uranus too. Do look for them on the BAA website at https://www.britastro.org/node/9275.
Look out for more Observer’s Challenges in the months to come – I do hope you will take up some of them. The ideal place to post your results is on your own BAA Member’s Page, but don’t forget to send them to the appropriate Section Director too. We also aim to publish a selection of results from future Observer’s Challenges in the Journal from time to time.

Our Spring meeting in Eastbourne
I hope to see many of you at the Spring Meeting at Eastbourne on Saturday April 29. Hosted by Eastbourne AS, the theme is planets in our solar system and beyond. Talks will cover current and future planetary missions and how amateurs can contribute, either by making observations from the ground or by analysing and processing data released into the public domain. Speakers include BAA Section Directors Dr John Rogers and Mike Foulkes, as well as Prof David Rothery, from the Open University and a very good friend of the BAA, who will talk on ‘Mercury: new insights into the Sun’s closest planet’. A booking form was included with your February Journal, and you can also book online on the BAA website.
Looking slightly further ahead, the Ordinary Meeting on May 31 will feature the George Alcock Memorial Lecture, this year presented by Dr Richard Miles on ‘Comet IRAS-Araki-Alcock and other comet discoveries from the UK’.

LED street lights and the amateur astronomer
Unfortunately light pollution is something that many of us struggle with, be it a street light next to our observing site or skyglow from major conurbations. We all owe a debt of gratitude to Bob Mizon and his team at the BAA’s Commission for Dark Skies (CfDS) for the important work they do on our behalf in fighting this scourge.
But there is much more work to do. As many will be aware, a revolution in street lighting is already well advanced with the introduction of LED street lights across many parts of the UK. The result for astronomers has been a mixed bag. Some have reported a reduction in local light pollution and skyglow, but for others it is very much a retrograde step. The effect depends on many factors, such as how bright the LED units are, the design of the luminaires (light fittings) and where they are located relative to the observer.
However, one thing is becoming clear and that is that many local authorities are opting to install the cheaper white LEDs, which have a strong blue spectrum. The CfDS is gathering data on the effects of these LEDs, not just on the night sky, but also their worrying effects on human health and wildlife.
I therefore experienced some trepidation recently when workmen and a cherry picker arrived unannounced in my road to replace the existing street lights with LEDs. I had specifically chosen to move to my village as it enjoys relatively dark skies, with the Milky Way visible on moonless nights – in fact I brought light pollution maps of the area to the estate agents when embarking on my home search! My neighbour who has lived in the village since WW2 informs me that the current street lights were installed in the 1970s, when opinion in the village was divided between continuing to have no street lights and the rather modest offering, at least by many standards, that was eventually selected. It’s actually the recent housing developments that have introduced more disturbing lighting schemes.
Anyway, within a day of the council crew arriving, all the lights in the area had been swapped for LEDs. So what is the result? Overall the situation has improved a little, mainly because they have employed full cut-off luminaires which means the light goes down onto the road rather than spreading out to the side – previously I could see the bulbs in the lights from a distance, but no longer.
Unfortunately the LEDs are the harsh white variety, but I notice that the general background illumination in the neighbourhood has decreased, making it noticeably darker in my back garden. I have still to determine whether general skyglow has changed as I haven’t had many really clear nights when the Moon is out of the way. I’ll definitely keep the situation under review!
Whatever my local result, it’s essential that we all continue to support the CfDS in its mission to protect the night. For more information about the CfDS and how you can help in the battle against light pollution visit https://www.britastro.org/dark-skies/. You can also subscribe to the CfDS newsletter via the BAA website, to keep abreast of the latest developments.

Your Association needs you!
The continued success of your Association depends on the hard work of many volunteers. At its centre, Council regulates and organises the scientific and public activities of the Association, and the Board of Trustees deals with day-to-day management, including financial matters.
If you are interested in helping to run the Association, why not consider standing for election to Council or the Board? We are always keen to welcome enthusiastic people with energy and ideas who want to serve the BAA and see it thrive. The nomination procedure is simple: all you need is for two other members to sign your nomination. Further details of the process are given on page 117 of this  Journal,  but don’t forget that nominations must be returned to the Office by May 12.
If you have any questions about what being on Council or the Board entails, please feel free to contact me – or any other member of either body. I for one find it hugely rewarding to serve our members and help to shape the BAA of the future and I know my fellow Councillors and Trustees share my experience. Maybe now is the time for you to step forward – you’ll be guaranteed a warm welcome!

Jeremy Shears, President