Wed, 04/24/2013 - 06:36
In the latest Newsletter, a lot of bright stars are included in the list of best-covered stars in de LPV program: alf Ori, eta Gem, rho Cas. When I try to make charts for these stars in VSP, I don't get it right. Is there a way to make charts for naked eye variables with VSP or should I use the older (but very practical) charts? Or is there somewhere a repository for handy charts that I am missing?
All the stars (and several more) that you mention have charts available in the ten star tutorial.
We have discussed creating a set of charts for the most observed naked eye variables, perhaps making them available as a pdf document you could download and print, but our current priority project is to create the sequences for the stars we are recommending in the upcoming DSLR manual. Many of those are also naked eye stars, suitable for visual observers, so we can kill two birds with one stone.
Then I think we will discuss making these nakes eye charts, or adding additional functionality to VSP to plot these wider field charts, much like the Binocular Charts are done now.
Thanks for the link! I'll start with these charts.
Are there any naked eye charts available besides the 10 star tutorial? The DSLR manual (mentioned above) doesn't seem to have any.
Specifically wondering about α Herculis and κ Ophiuchi, maybe others too. There are no comp stars above 32 in the Hercules chart.
VSP is certainly not designed to make charts for naked eye variables.
The best approach for stars not in any of the 10 star tutorials is to prepare a chart with any planetarium software and then select bright constant stars with magnitudes preferrable in VSP.
Some things about the stars you mentioned:
alpha Herculis is a small amplitude variable and it has a companion. This means that naked eye observations will be for the blended magnitude of the two.
The variable varies between V= 2.73 and 3.60 but the combined total range is V= 2.64 - 3.36.
But it usually varies much less than that. Difficult target.
The two main comparison stars are beta Her (V= 2.78) and kap Oph (V= 3.20). When it gets fainter, nu Oph (V= 3.33) and xi Ser (V= 3.54).
In extreme cases you can add zet Oph (V= 2.56).
And about kap Oph, as you have just noticed, this is not a variable star, it is a perfect comparison star for alf Her. So please do not observe it. Noone should observe it anymore. I have updated the VSX entry to reflect that.
Perfect, thank you Sebastian for the quick and detailed reply!