Celestial Atlas
PGC 57500 - 57999 ←PGC Objects: PGC 58000 - 58499→ PGC 58500 - 58999
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Page last updated Aug 8, 2022
Added PGC 58109 & 22333332

PGC 58109
(= MCG +07-34-030)
(= SDSS J162558.14+435746.4 + SDSS J162557.25+435743.5)

An interacting pair of galaxies in
Hercules (RA 16 25 57.4, Dec +43 57 45)
Western galaxy = a magnitude 14(?) lenticular galaxy (type E/S0? pec) at RA 16 25 57.2, Dec +43 57 44
Eastern galaxy = a magnitude 15.5(?) spiral galaxy (type (R')SB(rs)b pec) at RA 16 25 58.1, Dec +43 57 46
About the PGC Designation: Per Corwin, PGC followed MCG, so MCG +07-34-030 (which is this pair of galaxies) must be PGC 58109. However, a recent HST press release (the source of the images below) listed PGC 58109 as the galaxy to the west of this pair, which is actually PGC 2233332. Because of this error, there is bound to be confusion about the PGC designation in the future, which is why the single galaxy is discussed in the following entry, instead of on the usual page for PGC objects in the 2-million-plus range.
Physical Information: Based on a recessional velocity(*) relative to the Cosmic Background Radiation of 9630 km/sec (and H0 = 70 km/sec/Mpc), a straightforward calculation indicates that the pair of galaxies listed here is about 445 to 450 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 430 to 435 million light-years away at the time the light by which we see it was emitted, about 435 to 440 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 0.65 by 0.4 arcmin for the eastern galaxy and about 0.45 by 0.25 arcmin for the western galaxy (from the images below), the eastern galaxy is about 80 to 85 thousand light-years across, and the western galaxy spans about 55 to 60 thousand light-years. Since the recessional velocity for this pair of galaxies is only 130 km/sec larger than the corresponding value for the galaxy to their west, the three galaxies may be a gravitationally bound triplet.
(*): NED lists a 3K Vr of 9617 km/sec for the eastern galaxy and 9642 km/sec for the western one; since they are probably interacting, the average of the two values is the best estimate of their Hubble Flow velocity.
PanSTARRS image of the region near the single spiral galaxy designated PGC 58109 by HST and SIMBAD, and the pair of galaxies designated as PGC 58109 by HyperLEDA and NED
Above, a 12 arcmin wide PanSTARRS image showing the correct PGC designations
Below, a 2 arcmin wide PanSTARRS image of the three galaxies
PanSTARRS image of the single spiral galaxy incorrectly designated PGC 58109 by HST and SIMBAD, and the pair of galaxies correctly designated as PGC 58109 by HyperLEDA and NED
Below, a 1.9 arcmin wide image of the three galaxies (Image Credit ESA/Hubble & NASA, W. Keel
HST image of the single spiral galaxy incorrectly designated PGC 58109 by HST and SIMBAD, and the pair of galaxies correctly designated as PGC 58109 by HyperLEDA and NED
Below, a 0.75 arcmin wide HST image of the incorrect PGC 58109 (actually = PGC 2233332)
HST image of the spiral galaxy incorrectly designated PGC 58109 by HST and SIMBAD
Below, a 0.75 arcmin wide HST image of the correct PGC 58109
HST image of the pair of galaxies correctly designated as PGC 58109 by HyperLEDA and NED

PGC 2233332 (not =
PGC 58109)
A magnitude 15.5(?) spiral galaxy (type (R')SA(s)a) in Hercules (RA 16 25 51.5, Dec +43 57 47)
About the PGC Designation: Per Corwin, PGC followed MCG, so MCG +07-34-030 (which is the pair of galaxies to the east of this one) must be PGC 58109. However, a recent HST press release (the source of the images in the preceding entry) listed PGC 58109 as the galaxy to the west of this pair, which is actually PGC 2233332. Because of this error, there is bound to be confusion about the PGC designation in the future, which is why the single galaxy is discussed in this entry, instead of on the usual page for PGC objects in the 2-million-plus range.
Physical Information: Based on a recessional velocity relative to the Cosmic Background Radiation of 9500 km/sec (and H0 = 70 km/sec/Mpc), a straightforward calculation indicates that PGC 2233332 is about 440 to 445 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 425 to 430 million light-years away at the time the light by which we see it was emitted, about 430 to 435 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 0.6 by 0.35 arcmin (from the images below), the galaxy is about 75 thousand light-years across. Since the recessional velocity for this galaxy is only 130 km/sec less than the corresponding value for the pair of galaxies to its east, the three galaxies may be a gravitationally bound triplet.
HST image of spiral galaxy PGC 2233332, sometimes misidentified as PGC 58109
Above, a 0.75 arcmin wide image of PGC 2233332 (Image Credit ESA/Hubble & NASA, W. Keel
Below, a 0.2 arcmin wide image of the galaxy's central region (Image Credit as above); for wider-field images see PGC 58109
HST image of the central region of spiral galaxy PGC 2233332, sometimes misidentified as PGC 58109

PGC 58150 (=
Arp 66)
(= UGC 10396 = CGCG 276-019 = MCG +09-27-040)

A magnitude 14(?) spiral galaxy (type SAB(rs)bc) in Draco (RA 16 26 53.3, Dec +51 33 18)
Based on a recessional velocity of 6195 km/sec, PGC 58150 is about 285 to 290 million light years away. Given that and its apparent size of 1.15 by 0.55 arcmin (from the images below), it is about 95 to 100 thousand light years across. The small knot at the end of the northern arm that appears to be the reason for its Arp listing is at 16 26 54.2, +51 33 38 (1 second of time east and 20" north of the center of the galaxy); whether it is a separate object or merely part of PGC 58150 itself, it appears to have no separate listing or any other information available.
Use By the Arp Atlas: PGC 58150 is used by The Arp Atlas of Galaxies as an example of a spiral galaxy with a small high surface brightness companion.
SDSS image of region near spiral galaxy PGC 58150, also known as Arp 66
Above, a 12 arcmin wide SDSS image centered on PGC 58150
Below, a 1.25 arcmin wide SDSS image of PGC 58150
SDSS image of spiral galaxy PGC 58150 and its apparent high surface brightness companion, also known as Arp 66
Celestial Atlas
PGC 57500 - 57999 ←PGC Objects: PGC 58000 - 58499→ PGC 58500 - 58999
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