Absolute color - magnitude diagram

AI Thread Summary
A user is seeking a source for absolute color-magnitude diagrams (B-V and V) to determine distances to star clusters through Main Sequence fitting, specifically requesting data tables for over 100 stars. They mention that while Simbad provides apparent magnitudes and distances, they prefer not to manually calculate absolute magnitudes. A response clarifies that capital letters in filters do not necessarily indicate absolute magnitudes and that apparent magnitudes are commonly used. The user reiterates their desire for ready-made data tables for nearby stars. The discussion highlights the challenge of sourcing comprehensive data for astronomical analysis.
captain.joco
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Hello all,

I am finding a distance to a cluster via Main Sequence fitting, and I don't know where to find an absolute color - magnitude diagram ( B-V, and V ). I can be from any star cluster, or sky region, as long as the magnitudes are absolute. I need the data tables, not just a pretty picture ( that Google with easily show ). If you have idea where to find some data, please do tell me ( I ideally, I would like to plot more then 100 stars on my color magnitude diagram ).

Thank You all!
J.
 
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simbad has apparent magnitudes for a lot of stars in both the B and V bands. It also has the distances to many of these stars so you can find their absolute magnitudes.

From my experience, when dealing with filters capital letters need not mean absolute magnitude. Usually B-V is done in apparent magnitude. It shouldn't matter except for preferential extinction which will be negligible for closer stars.
 
Hey thanks for your answer. I have thought of that, but I wouldn't like to do that manually for ~100 stars.. Isnt any ready data table of absolute magnitudes and colors out there ( at least for near by stars? ) Thanks
 
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