I have data that contains galactic latitude and longitude of stars. I have to determine all the stars that are within our milky way. How do I find it?
Stars beyond our own galaxy and its immediate neighbors are indistinct without a large telescope, so I assume the question is about the band across the sky, rich with faint stars.
The Milky Way's boundary is fuzzy, so its extent is expressed in terms of isophotes: lines of constant brightness per unit solid angle (e.g. square degree). It is wider near the central bulge (galactic longitudes around 0° or 360°) than away from it (around 180°). Most stars within galactic latitudes ±10° are in the Milky Way; most outside ±15° are not. At galactic latitudes in between, galactic longitude and the choice of isophote determine whether a star is in or out.