Light from the star betelgeuse takes 640 years to reach earth. how far away is betelgeuse in units of light-years? name any historical event that was occurring on earth at about the time the light left betelgeuse. is the distance to betelgeuse unusual compared with other stars?

Betelgeuse is 640 light years away from earth.

Explanation:

A light-year is an astronomical unit to measure the distance the light travels in a calendar year.

If the light from a star takes 640 years to reach us, then that star its 640ly away from us.

Betelgeuse has been labeled as a Variant Star, which means that its brightness can fluctuate over the course of years, this has made difficult for astronomers to measure the exact distance of the star. Right now the star is estimated to be around 613 and 881ly away from earth, although, for the sake of your second question, we will take 640 years as our estimated value.

In 1380 (640 years ago) the Battle of Kulikovo took place. A battle of remarkable importance to Russian history, in which the Russian army, led by Prince Dmitry of Moscow, defeated the Mongol army, defining a turning point in the Mongol dominance, and setting the bases for what Russia is today.

The distance is 641.8207 light years, and the star Betelgeuse is further away when compared to other stars

Historical event: Benedict XI succeeds Boniface VIII as pope (1302)

Explanation:

the solution is in the attached Word file

unable to answer the rest since your question is incomplete