Teams / Southern Gems / We need to select the main star for the tutorial
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Hello, teammates, I think that the star that we're going to use as an example on how to make a brightness estimate, needs to be very easy to find and thus, very bright. It will be the beginning of the story. I don't think it matters if it's easy or difficult regarding the data quality that we will get. If you take a look at the Northern tutorial, you will find that in the example, Betelgeuse is compared with Rigel (0.1 mag.) and Saiph (2.1 mag.). These are not the comparison stars we are going to use to make the brightness estimate because we have comp stars 04, 09, 12, 17 and 19 between Rigel and Saiph (and we have to use two consecutive comparison stars). Comparing the variable star with two very different and nearby stars will make it easier for people to see how the method works. The results obtined this way will not be useful but that's not the point if you follow... The thing is that newcomers learn how to make a brightness estimate. Once they get used to the method, they will take the official chart and use the proper comparison stars to do the job. That's why I support Betelgeuse to be that star (it's not only because we can borrow the example for the Northern tutorial!!)
However, Betelgeuse is a seasonal star. If we wanted people to get started right now, they couldn't do it... But no star sill be visible all year at a suitable altitude. lCarinae is visible most of the year but it is not as bright and easy to find for someone who's not familiar with the sky. Eta Aquilae is as seasonal as Betelgeuse and much dimmer. It is the easiest to observe but I don't think that we're talking about that here. So my votes go for alpha Ori in the first place or l Carinae as an alternative. But I am completely willing to choose the star all the team members think it's best.
Cheers,
Sebastian.
Dear Gem Teammates, After reading the explanation by Sebastian, I am changing my vote to Alpha Orionis. I am wondering if we should put somewhere on the page a warning not to use that page as the one for making the actual estimates to put in the data base. I am thinking that some people may think that the result they get doing the example might be fine for the datat base. Should we mention this on the page where they are learning to estimate? Thank you, Sebastian, for your explanation. I would like to see many more of you Gem teammates putting your opinions here too. Please respond! Thanks. Cheers, Joan
Hi Joan, Julio, all I think it's worth going back and re-reading this post from Sebastian and follow-up comments (e.g. from Mike): http://www.citizensky.org/teams/southern-gems/easy-or-difficult-stars From the viewpoint of the time of year visible (right now), magnitude range, and comparison stars, how about Eta Aquilae? It's a cepheid rather than an eclipsing system, but does that matter for the purpose we're talking about? Alan Plummer helps people get started with visual variable star observing. What do you think Alan? Donna? I've observed Eta Aquilae and Alpha Orionis(for my own training)a number of times.As a fairly inexperienced variable star observer myself,I'd favour Eta Aquilae. Just my $0.02 worth. Regards, David
Hi David, Are you referring to eta Aquila being easier to observe than alpha Orionis as the reason for choosing it over alpha Orionis? That is a good point, I think. Let's consider that star. What do you others think? Cheers, Joan
Hi Joan That's what I was thinking yes. I know Alpha Orionis is bright, but that doesn't necessarily mean it's easier. I'm also looking at this from my own (relatively limited) experience.As I've said though, I'm happy to defer to more experienced variable star observers and was pointing to Sebastian's post re: this. Regards, David