understanding the hertzsprung-russell diagram and its significance in stellar classification

abstract background wallpaper stellar classification luminosity temperature stars astrophysics astronomy spectral types main sequence giants dwarfs supergiants hertzsprung russell star formation evolution celestial objects visual representation data visualization astrophysical research chart cosmic phenomena observational light years galaxy universe lifecycle processes scientific diagram analysis properties scale brightness color index astronomical studies scheme galactic trends nebulae interstellar medium mass density energy output metrics