Astronomy 1020 Study guides, Class notes & Summaries

What is the difference between brightness and luminosity? - Brightness is how it appears to us, distance is a factor. Luminosity is how much total light a star gives off. What is parallax? - Over the course of a year, the star's position in the sky appears to shift back and forth, returning to its original position 1 year later. The amount of this shift— the angle between one extreme in the star's apparent motion and the other— is equal to twice the parallax. You can use parallax to fin...

How did Hubble classify galaxies? - -shape and structural properties -stellar content -gas and dust -star formation -stellar motion What are the different categories Hubble used to classified galaxies ? - Spirals, barred spirals, ellipticals, irregulars What are the characteristics of spiral galaxies? - -flattened galactic disk with spiral arms -central galactic bulge -extended halo of faint old stars -spirals are classified according to the size of the central bulge and tightness of...