Page last updated Dec 24, 2015|
A magnitude 17(?) galaxy (type S0/a?) in Horologium (RA 04 19 57.1, Dec -41 13 25)
Physical Information: Based on a recessional velocity of 42285 km/sec, a straightforward calculation indicates that PGC 112500 is about 1970 million light years away. However, for objects at such distances we should take into account the expansion of the Universe during the time it took their light to reach us. Doing that shows that the galaxy was about 1675 million light years away at the time the light by which we see it was emitted, about 1790 million years ago (the difference between the two numbers being due to the expansion of the intervening space during the light-travel time). Given that and its apparent size of about 0.25 by 0.2 arcmin, the galaxy is about 120 to 125 thousand light years across.
Above, a 12 arcmin wide DSS image centered on PGC 112500
Below, a 0.6 arcmin wide DSS image of the galaxy