Solving Extinction and Reddening in Photometric Analysis of M5 Globular Cluster

[taylrl2]

I am currently writing up a photometric analysis of globular cluster M5 which I am doing from a set of images i have taken in the B,V and R bands. The CMD i have produced is obviously too red and faint due to the effects of extinction and reddening. As I am trying to calculate a distance using the luminosity of the tip of the RGB this effect is quite crucial. I know its E(B-V) that i need to calculate but i can't for the life of me think how to do it, any ideas? Thanks

 

[Chronos]

It sounds like an instrument problem to me. Have you taken another set of images?

 

[matt.o]

The NASA Extragalactic Database (NED) gives extinction values in the direction of objects. For M5, scroll down the page http://nedwww.ipac.caltech.edu/cgi-...v_breaker=30000.0&list_limit=5&img_stamp=YES" and you'll find the extinction values for a number of passbands. Please read the notes and accompanying papers to ensure the numbers are appropriate for what you're trying to do.

 

[taylrl2]

Thanks, the NED looks like its got just what I need. Brilliant now I can get this typed up. Thanks once again uve made my week!