3 April 2019 at 7:00 pm #574302
I am vice-chair of the North Wales Astronomy society and I am considering ways to get the society involved in different observation programs. I am really trying to find something where we as a society can contribute and/ or collect our own data. The projects need to be relatively easy in order to suit a variety of different abilities. For those who are involved in societies do you or have you taken part in such projects and if so can you share those ideas? Any help will be appreciated.
Tracey6 April 2019 at 6:31 pm #580937
Naked eye observations of delta Cephei introduces people to variable star observing. This particular star has the benefit of being bright (visible in light polluted areas), good comparison stars nearby, circumpolar (it doesn’t matter what time of year it is and so suitable for long-term observation) and varies markedly over a short time scale (conducive to making it interesting to beginners).
Pooling the results of several of your members will help bring out the variations more clearly and phase-folding observations made over a period of weeks or months should show the nice sawtooth light curve of a classical Cepheid.
Somewhere I still have the observations I made as a young teenager. It’s how I became interested in observing variables.7 April 2019 at 7:26 am #580943Nick JamesParticipant7 April 2019 at 10:47 am #580944Tracie HeywoodParticipant
I’m always wary of the idea that making naked eye observations of variable stars is *still* a good way of introducing beginners.
Although several, such as delta Cephei, are visible with the naked eye from many locations in the UK, to make an accurate observation requires both the variable and comparison to be *easily* visible. Given that delta Cephei goes down to about mag 4.3 means that you need a limiting magnitude approaching 5.5. Personally, despite my observing site more or less achieving this in moonless skies, I find it easier to observe delta Cep using smaller binocular sizes nowadays.
Given that visual observations inevitably “jump around” a bit, especially for inexperienced observers, one thing that is needed is persistence – as it can take many observations before the saw-tooth pattern emerges from the “scatter”. The accompanying light curve shows SPA VSS observations of delta Cephei from 2017.
Fortunately nowadays, PC software makes the plotting of light curves a lot easier – no “folding” of light curves is required. The SPA VSS has a spreadsheet that can be downloaded: http://www.popastro.com/documents/DeltaCephei_phase_calc_blank.xlsx
You enter the dates, times and magnitudes. It then does the conversions and plots the phase-based light curve for you.7 April 2019 at 11:18 am #580945Nick WhiteParticipant
At Uni I was given the hi-tech task of using a straight stick with a tiny disc stuck to it at right angles to measure the ellipticity of the Moon’s orbit. Observations involved pointing the stick at the moon and adjusting the position of the disc so as to cover the Moon precisely. From week to week the disc had to be moved up and down the stick to account for the change in apparent diameter of the Moon as a result of its elliptical orbit…. The same kind of measurement could be performed using a basic digital camera on max zoom. I think we also had a stick with an arc on the end so that we could measure the angular separation between the Moon and bright stars, presumably with the aim of working out other parameters of its orbit (memory is a bit hazy).8 April 2019 at 11:08 am #580954Peta BosleyParticipant
I agree with Nick James comment. I belong to Hampshire Astronomical Group and we have 3 meteor cams at our Clanfield Observatory site (https://hantsastro.org.uk/). The Crayford team gave a great talk at BAA Winchester yesterday all about how they set up a camera and involved a lot of their members.10 April 2019 at 9:37 am #580964Andrew ThomasParticipant
Radio observing would make an interesting group activity and it’s especially suitable for our climate an it can continue in all weathers. There are a range of projects which can be carried out with varying expertise and on a limited budget. Observing the effect of solar flares is straight forward and John Cook (the BAA Radio Astronomy section co-ordinator) collates observations and writes them up in the BAA Journal.
If this sounds interesting please feel free to contact me directly firstname.lastname@example.org or John Cook via the RA section.10 April 2019 at 11:28 am #580965Jeremy ShearsParticipant
Lunar occultations could be an interesting project, especially to observe grazing occultations where several members of the AS could be spaced across/along the graze track. Could even be extended to asteroidal occultations.11 April 2019 at 7:30 am #580966
Tracie, I understand your concerns but my teenage observations were made from light-polluted suburban Derbyshire, not a dark site. Today, despite my aging eyes, I still have no difficulty at all observing it from home 10km due south of brilliantly lit Cambridge (the VS is circumpolar …) and in a garden lit by neighbours.
I do not know where Tracey’s members live in North Wales but I remember the skies being markedly darker (and cloudier) there than they were in Derbyshire and my guess is that they are likely darker than where I now live.15 April 2019 at 4:02 pm #580977Tracie HeywoodParticipant
Hi Paul, I have no doubt that beginners will “see” delta Cephei change in brightness. The question is whether these changes match the brightness variations of delta Cephei or whether they primarily reflect the largish scatter that is common in newcomers to visual observing. The UK weather is such that it is unusual for there to be 5 or more clear nights in a row. Hence observers are unlikely to follow delta Cephei through a single cycle of variation and instead will have a collection of adhoc observations spread over a period of time. I know from my early experience that converting such sets of observations into a single light curve can produce somewhat disappointing results, with many observations straying a long way from the (hoped for) neat light curve. The 2017 light curve that I included in my previous reply was, in contrast, primarily based on observations by SPA VSS members with many years experience.
Tracie (based in Leek, Staffs, not north Wales!)16 April 2019 at 7:33 am #580978
I really must dig up the observations I made …3 May 2019 at 3:57 pm #581026
Dear Paul and Tracie.
I do like the idea of variable star observations, especially naked eye as it is so simple to do. I think this is certainly one that I could present to the society especially as it has been relative to some of the lectures that we have had over the last 12 months.
Thank you3 May 2019 at 3:58 pm #581027
Radio astronomy is something that I am interested in. I have a couple of meteor and SID detectors set up. I have given talks in the past to the society and maybe we could have a build your own workshop.
Thank you3 May 2019 at 3:59 pm #581028
Thank you all for your suggestions. There are certainly some that I can use for future club projects. I just hope that it will spark interest from the group and that we can get involved in a project together.
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