Celestial Atlas
PGC 45500 - 45999 ←     PGC Objects: PGC 46000 - 46499 Link for sharing this page on Facebook     → PGC 46500 - 46999
Click here for Introductory Material
Page last updated Nov 1, 2012

PGC 46225 (with
PGC 1457659 = Arp 57)
A 15th-magnitude barred spiral galaxy (type SAbc) in Coma Berenices (RA 13 16 47.2, Dec +14 25 41)

Based on a recessional velocity of 18050 km/sec, a straightforward calculation indicates that PGC 46225 is about 840 million light years away. However, for objects as such distances we should take into account the Universal expansion during the time it took their light to reach us. Doing that shows that the galaxy was about 785 million light years away at the time the light by which we see it was emitted, about 805 million years ago (the difference between two numbers being due to the expansion of the intervening space during the light-travel time). Given that and its apparent size of 0.8 by 0.5 arcmin, PGC 46225 is about 180 thousand light years across. Aside from its apparent companion, PGC 46225 is in the same direction and at nearly the same distance as PGC 46234. The difference in their recessional velocities is small enough that it may be due to peculiar (non-Hubble expansion) velocities, so despite the odds that the two galaxies are unrelated, they may actually be more closely related to each other than it would otherwise appear.

SDSS image of spiral galaxy PGC 46225 and its apparent companion, PGC 1457659, which comprise Arp 57; also shown is spiral galaxy PGC 46234
Above, a 2.4 arcmin wide closeup of Arp 57; also shown is PGC 46234
Below, a 12 arcmin region centered on the pair
SDSS image of region near spiral galaxy PGC 46225 and its apparent companion, PGC 1457659, which comprise Arp 57; also labeled is spiral galaxy PGC 46234
Below, the same view with additional labels for PGC objects 1455622, 1458619, and 1459772
SDSS image of spiral galaxy PGC 46225 and its apparent companion, PGC 1457659, which comprise Arp 57; also labeled are spiral galaxy PGC 46234, and PGC Objects 1455622, 1458619 and 1459772

PGC 1457659 (with
PGC 46225 = Arp 57)
Listed here since an apparent companion of PGC 46225 (which see for images)
A 17th-magnitude galaxy (type S?) in Coma Berenices (RA 13 16 47.9, Dec +14 25 15)

(Listed in NED as Arp57 NED02.) Apparent size 0.25 by 0.2 arcmin; nothing else available, but if at the same distance as PGC 46225, it would be about 60 thousand light years across.


PGC 46234
A 16th-magnitude spiral galaxy (type Sb) in
Coma Berenices (RA 13 16 51.8, Dec +14 24 55)

Based on a recessional velocity of 17645 km/sec, a straightforward calculation indicates that PGC 46234 is about 820 million light years away. However, for objects as such distances we should take into account the Universal expansion during the time it took their light to reach us. Doing that shows that the galaxy was about 765 million light years away at the time the light by which we see it was emitted, about 790 million years ago (the difference between two numbers being due to the expansion of the intervening space during the light-travel time). Given that and its apparent size of 0.45 by 0.3 arcmin, the galaxy is about 100 thousand light years across. As noted at PGC 46225, it is possible that it and PGC 46234 are more closely related than their slightly different recessional velocities might imply.

SDSS image of spiral galaxy PGC 46234, also showing spiral galaxy PC 46225 and its apparent companion, PGC 1457659, which comprise Arp 57
Above, a 2.4 arcmin wide closeup of PGC 46234; also shown are PGC 46225 and PGC 1457659
See PGC 46225 for a wide-field view

PGC 46461
A 15th-magnitude elliptical galaxy (type E1?) in
Hydra (RA 13 19 32.0, Dec -24 29 03)

PGC 46461 is interacting with PGC 46464, so the two must be at the same distance. The recessional velocity of PGC 46461 is 9835 km/sec, and for PGC 46464 is 10495 km/sec, which should imply a distance based on an average recessional velocity of 10165 km/sec; but the listed recessional velocity for the pair is only 9555 km/sec, suggesting substantial uncertainty in either the individual or combined values. Based on an intermediate average of 9860 km/sec, the pair are about 460 million light years away, obviously give or take several millions of light years. Given that and its apparent size of 0.75 by 0.65 arcmin, PGC 46461 is about 100 thousand light years across.

DSS image of elliptical galaxy PGC 46461 and spiral galaxy PGC 46464, which comprise an interacting pair
Above, a 2.4 arcmin wide closeup of PGC 46234
Below, a 1.2 arcmin wide detail of the pair
(Image Credits: NASA/ESA/Hubble Heritage (STScI/AURA)-ESA/Hubble Collaboration, & W. Keel (U. of Alabama, Tuscaloosa))
HST image of elliptical galaxy PGC 46461 and spiral galaxy PGC 46464, which comprise an interacting pair
Below, a 12 arcmin wide region centered on the interacting pair
DSS image of region near elliptical galaxy PGC 46461 and spiral galaxy PGC 46464, which comprise an interacting pair

PGC 46464
A 15th-magnitude spiral galaxy (type Sbc pec) in
Hydra (RA 13 19 33.2, Dec -24 29 25)

PGC 46464 is interacting with and silhouetted against PGC 46461 (which see for images), so the two must be at the same distance. The recessional velocity of PGC 46464 is 10495 km/sec, and for PGC 46461 is 9835 km/sec, which should imply a distance based on an average recessional velocity of 10165 km/sec; but the listed recessional velocity for the pair is only 9555 km/sec, suggesting substantial uncertainty in either the individual or combined values. Based on an intermediate average of 9860 km/sec, the pair are about 460 million light years away, obviously give or take several millions of light years. Given that and its apparent size of 0.85 by 0.3 arcmin, PGC 46464 is about 115 thousand light years across.

Celestial Atlas
PGC 45500 - 45999 ←     PGC Objects: PGC 46000 - 46499     → PGC 46500 - 46999