HCG 87: A Small Group of Galaxies
From NASA’s Astronomy
Picture of the Day
Sometimes galaxies form
groups. For example, our own Milky
Way Galaxy is part of the Local
Group of Galaxies.
Small, compact groups,
like Hickson Compact Group 87 (HCG 87) shown
below, are interesting partly because they slowly self-destruct.
Indeed, the galaxies of HCG 87 are gravitationally stretching each
other during their 100-million year orbits around a common center.
The pulling
creates colliding gas that causes bright bursts of star
formation and feeds matter into their active galaxy centers.
HCG
87 is composed of a large edge-on spiral
galaxy visible near the image center, an elliptical
galaxy visible to its right, and a spiral galaxy visible near the top.
The small spiral near
the center might be far in the distance. Several stars from our Galaxy are also visible in the
foreground. Studying groups like HCG 87 allows insight into how all galaxies
form and evolve.
