 T l Guitar ♥ l l Bed Police l S
4 points to francis!
Then Sun is located in the outer part of the galaxy, at a distance of 2.7 × 1017 km (1.7 × 1017 mi) from the center. The Sun, which is moving around the center at a velocity of 220 km/s (140 mi/s), takes 250 million years to complete one trip around the center of the galaxy. The Sun has circled the galaxy more than 18 times during its 4.6-billion-year lifetime.
How is the brightness of a star measured? |