Celestial Atlas
PGC 44000 - 44499 ←PGC Objects: PGC 44500 - 44999 Link for sharing this page on Facebook→ PGC 45000 - 45499
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Page last updated Feb 2, 2019

PGC 44709
A magnitude 15.8 lenticular galaxy (type S(rs)0/a?) in
Coma Berenices (RA 13 00 10.2, Dec +27 51 50)
Physical Information: Based on a recessional velocity of 9900 km/sec (and H0 = 70 km/sec/Mpc), a straightforward calculation indicates that PGC 44709 is about 460 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 445 million light years away at the time the light by which we see it was emitted, about 450 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 0.35 by 0.35 arcmin (from the images below), the galaxy is about 45 thousand light years across. Note: Although generally listed as a member of the Coma Cluster, its large recessional velocity probably means that PGC 44709 is actually a background galaxy; and although it appears to be a companion of PGC 44716, it is at least 150 million light years further away from us.
SDSS image centered on PGC 44709, also showing NGC 4876 and NGC 4898
Above, a 12 arcmin wide SDSS image centered on PGC 44709, also showing NGC 4876 and 4898
Below, a 1.8 arcmin wide SDSS image of the galaxy and three of its nearest neighbors
(PGC 44716, PGC 126762 and "PGC 4628454")
SDSS image showing spiral galaxy PGC 44709, also showing PGC 44716, PGC 126762 and 'PGC 4628454'
Below, a 1.75 by 1.25 arcmin wide HST image of the region (Image Credit ESA/Hubble & NASA, Cramer et al.)
Also shown, in false-color, is the gas torn from PGC 44716 by ram-pressure stripping
(Note: The HST press release understates the apparent size of the region)
HST image showing lenticular galaxy PGC 44709, also showing PGC 44716, PGC 126762 and 'PGC 4628454'
Below, a 0.7 by 0.75 arcmin wide HST image of the region near PGC 44709 (Image Credit as above)
HST image showing lenticular galaxy PGC 44709; also shown are PGC 44716 and 'PGC 4628454'

PGC 44716
A magnitude 15.6 spiral galaxy (type SABa?) in
Coma Berenices (RA 13 00 09.2, Dec +27 51 59)
Designation Note: NED incorrectly lists PGC 44716 as the apparent pair of galaxies, PGC 44716 and PGC 44709 (apparent, because they are actually at very different distances). As a result, a search of NED for PGC 44716 should use MRK 0060 NED01 or SDSS J130009.14+275159.3.
Physical Information: Based on a recessional velocity of 5135 km/sec (and H0 = 70 km/sec/Mpc), PGC 44716 is about 240 million light years away, but it is thought to be a member of the Coma Cluster of galaxies, which is about 320 million light years away, and the ram-pressure stripping of gas in its core by its motion through the intergalactic medium which fills that cluster (and may have even more mass than the galaxies in the cluster) pretty much confirms that it is a member of the Cluster (although probably in the part of the cluster closer to us), and merely has a peculiar (non-Hubble expansion) velocity well in excess of 1000 km/sec (which would help explain the spectacular effect of its motion through the intergalactic medium). Such large 'peculiar' motions are not unusual in very rich clusters of galaxies, because the large mass of the cluster can allow it to hold onto galaxies with large peculiar motions, and in fact is usually the cause of those motions. Assuming that it is on the 'near' side of the Coma Cluster and using an estimated distance of about 300 million light years and its apparent size of about 0.4 by 0.25 arcmin (from the images below), PGC 44716 is about 35 thousand light years across.
SDSS image centered on PGC 44716, also showing NGC 4876 and NGC 4898
Above, a 12 arcmin wide SDSS image centered on PGC 44716, also showing NGC 4876 and 4898
Below, a 1.8 arcmin wide SDSS image of the galaxy and three of its nearest neighbors
(PGC 44709, PGC 126762 and "PGC 4628454"
SDSS image showing spiral galaxy PGC 44716, also showing PGC 44709, PGC 126762 and 'PGC 4628454'
Below, a 1.75 by 1.25 arcmin wide HST image of the region (Image Credit ESA/Hubble & NASA, Cramer et al.)
Also shown, in false-color, is the gas torn from PGC 44716 by ram-pressure stripping
(Note: The HST press release understates the apparent size of the region)
HST image showing spiral galaxy PGC 44716 and the gas torn from it by ramjet-pressure stripping, also showing PGC 44709, PGC 126762 and 'PGC 4628454'
Below, a 0.7 by 0.75 arcmin wide HST image of the region near PGC 44716 (Image Credit as above)
HST image showing spiral galaxy PGC 44716; also shown are PGC 44709 and 'PGC 4628454'
Celestial Atlas
PGC 44000 - 44499 ←PGC Objects: PGC 44500 - 44999→ PGC 45000 - 45499