Principle Galaxy Catalog (PGC) Objects 69000 to 69499 (original) (raw)

Page last updated July 14, 2024

PGC 69114 (= MCG -02-57-015)
A magnitude 15.0(?) spiral galaxy (type SBd? pec?) in Aquarius (RA 22 32 46.7, Dec -14 05 49)
For anything else, see here

PGC 69155 (= ESO 468-013 = MCG -05-53-015)
A magnitude 14(?) elliptical galaxy (type E2) in Pisces Austrinus (RA 22 33 44.1, Dec -27 14 45)

Physical Information: Based on a recessional velocity relative to the Cosmic Background Radiation of about 6610 km/sec (and H0 = 70 km/sec/Mpc), a straightforward calculation indicates that PGC 69155 is about 305 to 310 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 300 million light-years away at the time the light by which we see it was emitted, just under 305 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 0.55 by 0.45 arcmin (from the images below), the galaxy is about 45 to 50 thousand light-years across.
"Companion" Note: Since PGC 69155 is less than half a minute of time to the east of NGC 7306, if they had similar distances they could be companions; but since PGC 69155 is much further away from us, it is merely a background galaxy; still, it seems reasonable to show their relative positions, as in the wide-field image below.

Above, a 12 arcmin wide PanSTARRS image centered slightly to the west of PGC 69155, to also show NGC 7306
Below, a 1 arcmin wide PanSTARRS image of PGC 69155

PGC 69251 (= PGC 193119 = ESO 238-018)
A magnitude 14(?) spiral galaxy (type SAB(s)dm) in Grus (RA 22 35 43.8, Dec -50 53 27)
Above, a 12 arcmin wide DSS image centered on PGC 69251

PGC 69253 (= NGC 7314 = Arp 14)
A magnitude 11.0 spiral galaxy (type SAB(rs)bc?) in Piscis Austrinus (RA 22 35 46.2, Dec -26 03 02)
For anything else see NGC 7314

PGC 69293 (= Arp 3)
A magnitude 12.9 spiral galaxy (type SA(s)m) in Aquarius (RA 22 36 35.0, Dec -02 54 25)

Physical Information: Based on a recessional velocity of 1690 km/sec (and H0 = 70 km/sec/Mpc), Arp 3 is about 75 to 80 million light years away, in good agreement with a single redshift-independent distance estimate of about 75 million light years. Given that and its apparent size of 2.4 by 2.15 arcmin (from the images below), it is about 55 thousand light years across.
Arp Atlas Designation: The galaxy is one of six chosen by Halton Arp for his Atlas of Peculiar Galaxies as an example of spiral galaxies of low surface brightness, hence its designation as Arp 3, with the note "low surface brightness dwarf".

Above, a 12 arcmin wide SDSS image centered on PGC 69253
Below, a 2.4 arcmin wide SDSS image of the galaxy

PGC 69475 (= ESO 289-048)
A magnitude 13.7 spiral galaxy (type SAB(s)d sp) in Grus (RA 22 40 56.9, Dec -45 39 37)

Note About Classification: The type is taken from the Spitzer Survey of Stellar Structure in Galaxies. "sp" indicates a "spindle" (edge-on galaxy), which makes classification more difficult than usual.
Note About DSS Image "Double" Star: The apparently "double" magnitude 13.8 star a few arcminutes south of the galaxy, shown as a red star to the southeast of a blue one, is actually a single star, the "high-proper motion" star L 357-25, which has a proper motion (a change in its apparent position) of nearly half an arcsecond per year, or about 45 arcseconds per century. The double image is due to the fact that the star moved by a noticeable amount during the time between taking the red and blue images of the region, and is now still further to the southeast (how far depends on when "now" is; as I write this, in 2021, it's about another width of the red image down and to the left). This rapid change in position is partly due to the star's being only about 115 light-years away, but mostly because it is moving in a different direction from that of the Sun and most of the other stars in our vicinity, so that the difference in our motions make its motion look faster, just as cars traveling in the opposite direction from your car have a very fast motion relative to you, while cars driving in the same direction as you mostly seem to be staying in the same relative position. Most of the stars near us are going "around" the Galaxy in the same direction we are, so although some are moving a little faster and gaining on us and some a little slower and we are gaining on them, our relative motions are very small compared to our distance, and they appear to be more or less "fixed" in position (whence the term "the fixed stars"). L 357-25 must be moving inwards, toward the center of the Galaxy, or outward, away from the center, which are both very different motions from ours, so its relative motion looks very fast, even though it is probably moving at only about the same speed that we are.

Above, a 12 arcmin wide DSS image centered on PGC 69475, also showing L 357-25