Affiliation
American Association of Variable Star Observers (AAVSO)
Fri, 08/11/2017 - 02:11
Hi Guys,
Am I missing something? Whatever I try, I can not get the Variable Star Plotter to produce a useful chart for observing Algol. Everything I try just produces the error "No comparison stars were found in this field.". I'm trying to produce a chart which matches my scope's field-of-view with a decent number of calibrated comparison stars and their magnitudes.I've tried setting the field of view to the maximum 1200' etc., just can't produce anything. Always get ""No comparison stars were found in this field."".
To clarify, just trying to produce a chart for Algol which has labelled comparison stars and also their magnitudes.
Surely a chart of Algol is possible, what am I missing?
Many thanks, Phil.
1. It is quite easy (see the screenshots).
2. To get the list of comparioson star just push Photometry Table for This Chart
Velimir
Phil,
it all depends on what you want to do.
If you are talking about visual observations, VSP is not suitable to draw charts for such bright naked eye variables.
The field of view is limited. We even had trouble creating charts for the brightest stars in the Binocular program, so the situation gets worse for naked eye variables.
But for visual observations of some naked eye variables, we can use the charts we made for the Citizen Sky project back then and that we are still available through the 10 Star Tutorials.
On page 12 of the Northern Hemisphere 10 Star Tutorial you have a chart to observe Algol with bright comparison stars.
That's the best option you have if you are a visual observer. If not, VSP should be used as Velimir explained.
Cheers,
Sebastian
Thanks Guys,
OK I managed to produce a chart! But all the comparison stars in the photometry table are listed only be their AUID. How can I search some and convert the AUID to more common star designations eg. HD etc.?
Thanks, Phil.
Hi Phil,
You can use VSX to find names for the AUIDs. Go to VSX (https://www.aavso.org/vsx) and choose Search. Enter an AUID into the object field, and click the Search button at the bottom.
Good observing,
Elizabeth
Hi, I tried this. AUID 000-BBF-752 (which I think is ome Per based on the RA and Dec) doesn't find any star on VSX. What am I doing wrong?
Hi Phil,
VSX is database for variable stars. Normaly the comparison stars are constant, so they will not appear in VSX.
You can use the coordinates of the stars and search for catalogues in VisieR database. As you know the stars usualy have more than one designation so you can choose among the catalogues in VisieR to get the apropriate data.
For example your star 000-BBF-752 is equal to SAO 56224, magnitude 4.8 in V band (see the screenshot)
Velimir
Hi Phil,
Don't include 'AUID' - just put the number 000-BBF-752
best,
Elizabeth
Hi Elizabeth and all,
Even when VSX allows AUID searches, you won't find any results searching for comparison stars AUIDs because they are not variable stars and thus they are not in VSX.
The question here is: Phil, why do you need the HD numbers? Giving the magnitude label in the chart is enough to identify the comparison stars.
Cheers,
Sebastian
Uh crumbs, how? Algol is magnitude ~2. The comp stars on the chart I produced on AAVSO are magnitudes ~4, 8, 9 and 10. Not much use really for getting the chart aligned etc.!
Phil,
I already replied about visual charts for Algol.
You can't use VSP for such a purpose.
Cheers,
Sebastian
So what IS it designed for. I'm doing DSLR photometry. So AAVSO can't plot a chart with comparison stars for Algol? Is there a minimum magnitude at which the chart facilty becomes useful e.g. mag 6, 7 , 8 , 9 , 10? It seems ridiculous to me that you can't plot a simple chart for Algol on the world's biggest variable star observer's website, AAVSO. What am I missing? Am I only supposed to be interested in variables that are mag 7 or greater?
It is the first time that you mention that you're doing DSLR photometry.
Then the chart you can get with VSP is appropriate because you don't necessarily need stars of the same magnitude of the variable as in the case of visual observations.
So you'll get photometry for stars in the surroundings using VSP.
If you still need a wide field chart to identify the field, you can use the chart from the 10 Star Tutorial or make your own chart with your planetarium software. VSP is not meant to be a planetarium software but works very well for its purpose, it is useful for nearly all variables fainter than mag. 4 or so and gives you the photometric information for any comparison star in those fields.
Cheers,
Sebastian
Thanks for that Sebastian, useful comments! :-)
Hi Guys, thanks for that, it explains why I can't find the comp stars in VSX. I was trying to avoid searching by RA and DEC in Vizier/Sinbad. Is there a database anywhere that maps AUIDs to their other identifiers? If not, there should be!
I want the other identifiers e.g. HD, SAO so that I can find them in planetarium software e.g. Stellarium and help me to align my charts so I know what I'm looking at?
Hi guys, I'm new to aavso and would like to know when If I'll be able to watch Algol eclipse in September or October (I live in Los Angeles), and how I'll be able to watch a cy aqr type or any other short period variable (what equipment to use and when).
thanks.