This observation is one of a series which
aims to get to know our galactic neighbors. Hubble has observed around three
quarters of known galaxies within about 10 megaparsecs of Earth in enough
detail to resolve their brightest stars and establish distances to these
galaxies. A team of astronomers proposed using small gaps in Hubble’s observing
schedule to acquaint ourselves with the remaining quarter of these nearby
galaxies.
The megaparsec – meaning one million
parsecs – is a unit used by astronomers to chart the mind-bogglingly large
distances involved in astronomy. The motion of Earth around the Sun means that
stars appear to slightly shift against very distant stars over the course of a
year. This small shift is referred to as parallax and is measured in angular
units: degrees, minutes, and seconds. One parsec is equivalent to the distance
creating a parallax of one-arcsecond and is equivalent to 3.26 light-years or
30.9 trillion kilometers (19.2 trillion miles). The closest star to the Sun is
Proxima Centauri, which lies 1.3 parsecs away.
Text credit: European Space Agency (ESA)
Image credit:
ESA/Hubble & NASA, R. Tully
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