I'm trying to retrieve b and v magnitudes for a specific star from the Sloan Digital Sky Survey (SDSS) database, but I'm facing some challenges with my code.
Here are my requirements:
I need to input the name of the star. Using the star's name, I want to query the SDSS database to get the b and v magnitudes.Ill use this in the Ballesteros formula to find the temperature of a star. The code should handle cases where the star name might not be in the SDSS database. I've tried using the astroquery package and the SDSS.query_region method, but I'm encountering issues, and the magnitudes are not being retrieved as expected.
Could you please help me with the correct code or suggest an alternative approach to obtain the required magnitudes from the SDSS database?
Im able to get the ra,dec magnitudes like this : object_coord = SkyCoord.from_name(self.object_name) is there a same way for obtaining b and v?
You won't find B and V magnitudes in the SDSS database for the simple reason that the SDSS imaging surveys only ever observed in the SDSS ugriz filter set. The SDSS imaging camera was a drift scan camera that passed the sky through the SDSS r, i, u, z, and g filters in the respective rows of the CCDs in the array, in that order. The other issues are that the SDSS pipeline and database reports fluxes and magnitudes in "nanomaggies" and asinh magnitudes respectively, whereas the B and V magnitudes are in the Vega magnitude system.
There have been various reported transformations between the SDSS ugriz and the Bessell UBVRI systems. The correct one to use will depend on the type of science that you are wanting to do, but based on your question, it seems like you want to use the transformations that are intended for stars and take care to apply it to objects within the valid color range that is is stated for the transformation.