Page last updated Dec 24, 2015|
A magnitude 17(?) spiral galaxy (type Sa? pec?) in Virgo (RA 13 58 36.4, Dec -11 59 38)
Physical Information: Based on a recessional velocity of 20740 km/sec, a straightforward calculation indicates that PGC 105500 is about 965 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 890 million light years away at the time the light by which we see it was emitted, about 920 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 0.3 by 0.15 arcmin, the galaxy is 75 to 80 thousand light years across.
Above, a 12 arcmin wide DSS image centered on PGC 105500
The "bright" star (HD121865) is 7th magnitude
Below, a 0.6 arcmin wide DSS image of the galaxy