Celestial Atlas
PGC 29000 - 29499 ←     PGC Objects: PGC 29500 - 29999 Link for sharing this page on Facebook     → PGC 30000 - 30499
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Page last updated May 21, 2016

PGC 29529, the Vela Ring Galaxy
A magnitude 13(?) spiral ring galaxy (type (R)SB(rs)a? pec) in
Antlia (RA 10 09 05.5, Dec -38 24 35)
Physical Information: PGC 29529 is part of a pair with PGC 29531. The ring galaxy was undoubtedly created by a nearly direct collision with its neighbor, which moved through it toward us and to the northeast. Such collisions create a gravitational shock wave which moves outward from the center of the galaxy, compressing interstellar gas to form hot, bright new stars, which light up the region of their formation, giving the impression of a ring. Just like water waves spreading away from a rock thrown into a pond do not indicate a significant outward movement of the water itself, but only the wave passing through the water, the stars in the ring are not moving outward, but the ring gradually expands as the shock wave moves outward, and the hot bright stars that currently light it up age, die and become too faint to continue to illuminate the region inside the current larger, younger portion of the ring. As a result, a ring of the size shown here must have been caused by a collision that occurred millions of years ago.
     Given the obvious interaction between the two galaxies, they must be at essentially the same distance from us, so the difference in their radial velocities (about 4945 km/sec for PGC 29529 and 4480 km/sec for PGC 29531) does not represent a difference in their distance, but their "peculiar velocity" (the difference in their motion relative to each other). That difference indicates that PGC 29531 was behind PGC 29529 prior to their collision, and is now in front of it, having moved about 465 km closer to us for each second since their interaction (or about 0.00155 light years for each year since their collision). It also means that they are much further apart than they appear, as their tangential velocity (from side to side relative to our line of sight) is undoubtedly much smaller than their fairly large difference in radial velocity. Based on their average recessional velocity of 4715 km/sec, the pair is about 220 million light years away. Given that and its apparent size of about 1.7 by 0.95 arcmin, PGC 29529 is about 105 to 110 thousand light years across.
ESO image of region near spiral ring galaxy PGC 29529, also showing PGC 29531
Above, a 12 arcmin wide ESO/DSS composite image centered on PGC 29529, also showing PGC 29531
(Image Credit above and below ESO; Acknowledgement Jean-Christophe Lambry)
Below, a 2 by 2.6 arcmin wide ESO image of the galaxies; the "bright" star is 9th magnitude HD 88170
ESO image of spiral ring galaxy PGC 29529 and elliptical galaxy PGC 29531

PGC 29530 (= PGC 733849 =
NGC 3137)
A magnitude 11.5 spiral galaxy (type SAB(s)cd?) in Antlia (RA 10 09 07.4, Dec -29 03 51)
For anything else see NGC 3137

PGC 29531
A magnitude 13(?) elliptical galaxy (type E4? pec?) in
Antlia (RA 10 09 08.3, Dec -38 23 46)
Physical Information: PGC 29531 is part of a pair with PGC 29529 (which see for images and a detailed discussion of the pair). The ring galaxy was undoubtedly created by a nearly direct collision with PGC 29531, which has now moved through it toward us and to the northeast. Based on their average recessional velocity of 4715 km/sec, the pair is about 220 million light years away. Given that and its apparent size of about 1.0 by 0.6 arcmin, PGC 29531 is about 65 thousand light years across.

PGC 29532 (=
NGC 3138)
A magnitude 14.8 spiral galaxy (type Sbc?) in Hydra (RA 10 09 16.7, Dec -11 57 24)
For anything else see NGC 3138

PGC 29544 (=
NGC 3141)
A magnitude 15.4 lenticular galaxy (type S0/a?) in Hydra (RA 10 09 19.9, Dec -16 39 12)
For anything else see NGC 3141

PGC 29548 (=
NGC 3140)
A magnitude 14.0 spiral galaxy (type SB(rs)bc?) in Hydra (RA 10 09 27.8, Dec -16 37 41)
For anything else see NGC 3140

PGC 29579 (=
NGC 3143)
A magnitude 14.3 spiral galaxy (type SB(s)b?) in Hydra (RA 10 10 04.0, Dec -12 34 53)
For anything else see NGC 3143

PGC 29583 (=
NGC 3139)
A magnitude 13.5 lenticular galaxy (type S0/a?) in Hydra (RA 10 10 05.2, Dec -11 46 41)
For anything else see NGC 3139

PGC 29586 (= PGC 1003160 =
NGC 3142)
A magnitude 13.8 spiral galaxy (type SABab? pec?) in Sextans (RA 10 10 06.3, Dec -08 28 47)
For anything else see NGC 3142

PGC 29591 (= PGC 952793 =
NGC 3145)
A magnitude 11.7 spiral galaxy (type SB(rs)bc?) in Hydra (RA 10 10 09.9, Dec -12 26 02)
For anything else see NGC 3145

PGC 29597 (= "
NGC 3136B")
A magnitude 11.7 lenticular galaxy (type E/S0?) in Carina (RA 10 10 12.9, Dec -67 00 18)
For anything else see "NGC 3136B"

PGC 29646 (=
NGC 3135)
A magnitude 13.5 spiral galaxy (type Sbc?) in Ursa Major (RA 10 10 54.4, Dec +45 57 01)
For anything else see NGC 3135

PGC 29663 (=
NGC 3146)
A magnitude 13.0 spiral galaxy (type SAB(r)ab?) in Hydra (RA 10 11 09.9, Dec -20 52 14)
For anything else see NGC 3146

PGC 29691 (= PGC 702917 =
NGC 3157 = IC 2555)
A magnitude 13.2 spiral galaxy (type SB(s)bc?) in Antlia (RA 10 11 42.4, Dec -31 38 34)
For anything else see NGC 3157

PGC 29722 (=
NGC 3134)
A magnitude 13.7 lenticular galaxy (type S0?) in Leo (RA 10 12 29.3, Dec +12 22 38)
For anything else see NGC 3134

PGC 29730 (=
NGC 3156)
A magnitude 12.3 lenticular galaxy (type S0(r)a? pec) in Sextans (RA 10 12 41.2, Dec +03 07 46)
For anything else see NGC 3156

PGC 29747 (=
NGC 3153)
A magnitude 12.7 spiral galaxy (type SBcd? pec) in Leo (RA 10 12 50.5, Dec +12 40 00)
For anything else see NGC 3153

PGC 29759 (=
NGC 3154)
A magnitude 13.5 spiral galaxy (type S(rs)ab?) in Leo (RA 10 13 01.3, Dec +17 02 03)
For anything else see NGC 3154

PGC 29768 (= PGC 1413737)
A magnitude 15(?) spiral galaxy (type Sbc?) in
Leo (RA 10 13 12.7, Dec +12 39 27)
Historical Identification: At one time it was thought that PGC 29768 might be Todd 20c, an object recorded by David Todd while observing the region near NGC 3153 (= Todd 20b); in fact, that was the original reason for creating an entry for PGC 29768. However, Todd 20c is actually the 10th magnitude star 21 seconds of time to the east of the galaxy, so this serves as a warning to readers who run across that misidentification.
Physical Information: Based on a recessional velocity of 9525 km/sec, a straightforward calculation indicates that PGC 29768 is about 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 425 to 430 million light years away at the time the light by which we see it was emitted, about 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 0.8 by 0.4 arcmin, the galaxy is about 100 thousand light years across.
SDSS image of region near spiral galaxy PGC 29768, also showing NGC 3153
Above, a 12 arcmin wide SDSS image centered on PGC 29768, also showing NGC 3153
(Also shown is the star that is actually Todd 20c)
Below, a 0.9 arcmin wide SDSS image of the galaxy
SDSS image of spiral galaxy NGC 29768

PGC 29789 (=
NGC 3150)
A magnitude 14.6 lenticular galaxy (type (R)S0(rs)a?) in Leo Minor (RA 10 13 26.3, Dec +38 39 28)
For anything else see NGC 3150

PGC 29796 (=
NGC 3151)
A magnitude 13.8 lenticular galaxy (type (R)SAB0(r)a?) in Leo Minor (RA 10 13 29.1, Dec +38 37 11)
For anything else see NGC 3151

PGC 29798 (=
NGC 3165)
A magnitude 13.9 spiral galaxy (type SA(s)dm?) in Sextans (RA 10 13 31.3, Dec +03 22 30)
For anything else see NGC 3165

PGC 29800 (=
NGC 3162 = NGC 3575)
A magnitude 11.6 spiral galaxy (type SAB(rs)bc?) in Leo (RA 10 13 31.6, Dec +22 44 15)
For anything else see NGC 3162

PGC 29805 (= PGC 2137844 =
NGC 3152)
A magnitude 14.2 lenticular galaxy (type (R)SB0(s)a?) in Leo Minor (RA 10 13 34.1, Dec +38 50 36)
For anything else see NGC 3152

PGC 29814 (= PGC 1251971 =
NGC 3166)
A magnitude 10.4 lenticular galaxy (type SAB0(rs)a? pec) in Sextans (RA 10 13 45.7, Dec +03 25 29)
For anything else see NGC 3166

PGC 29822 (=
NGC 3158)
A magnitude 11.9 elliptical galaxy (type E3?) in Leo Minor (RA 10 13 50.5, Dec +38 45 54)
For anything else see NGC 3158

PGC 29825 (=
NGC 3159)
A magnitude 13.6 lenticular galaxy (type S0/a?) in Leo Minor (RA 10 13 52.8, Dec +38 39 16)
For anything else see NGC 3159

PGC 29830 (=
NGC 3160)
A magnitude 14.1 spiral galaxy (type Sb? pec) in Leo Minor (RA 10 13 55.1, Dec +38 50 35)
For anything else see NGC 3160

PGC 29837 (=
NGC 3161)
A magnitude 13.7 lenticular galaxy (type S0/a?) in Leo Minor (RA 10 13 59.2, Dec +38 39 26)
For anything else see NGC 3161

PGC 29846 (=
NGC 3163)
A magnitude 13.3 lenticular galaxy (type E/SA0? pec?) in Leo Minor (RA 10 14 07.1, Dec +38 39 09)
For anything else see NGC 3163

PGC 29855 (=
NGC 3169)
A magnitude 10.2 spiral galaxy (type SA(s)a? pec) in Sextans (RA 10 14 15.1, Dec +03 27 58)
For anything else see NGC 3169

PGC 29870 (=
NGC 3197)
A magnitude 13.5 spiral galaxy (type S(rs)bc?) in Draco (RA 10 14 27.7, Dec +77 49 13)
For anything else see NGC 3197

PGC 29883 (=
NGC 3173)
A magnitude 12.8 spiral galaxy (type SA(s)c?) in Antlia (RA 10 14 34.9, Dec -27 41 35)
For anything else see NGC 3173

PGC 29892 (=
NGC 3175)
A magnitude 11.2 spiral galaxy (type SAB(s)ab?) in Antlia (RA 10 14 42.2, Dec -28 52 18)
For anything else see NGC 3175

PGC 29907 (sometimes called
NGC 3176)
A magnitude 14.2 spiral galaxy (type S?) in Hydra (RA 10 14 52.3, Dec -20 00 46)
Since sometimes identified (misidentified?) as NGC 3176, for anything else see here
For a discussion of the probably nonexistent NGC 3176, see here

PGC 29928 (=
NGC 3164)
A magnitude 13.7 spiral galaxy (type S(rs)bc?) in Ursa Major (RA 10 15 11.4, Dec +56 40 19)
For anything else see NGC 3164

PGC 29949 (=
NGC 3144 = NGC 3174)
A magnitude 13.4 spiral galaxy (type SB(s)ab? pec?) in Draco (RA 10 15 32.1, Dec +74 13 13)
For anything else see NGC 3144

PGC 29950 (=
NGC 3171)
A magnitude 12.8 lenticular galaxy (type E/S0? pec?) in Hydra (RA 10 15 36.8, Dec -20 38 51)
For anything else see NGC 3171

PGC 29963 (sometimes called
NGC 3186)
A magnitude 14.1 lenticular galaxy (type S0?) in Leo (RA 10 15 53.4, Dec +06 57 50)
Since sometimes identified (misidentified?) as NGC 3186, for anything else see here
For a discussion of the probably nonexistent NGC 3186, see here

PGC 1310913
A magnitude 15.0 lenticular galaxy (type SAB0? pec?) in
Leo (RA 10 15 52.6, Dec +06 57 33)
Since a possible companion of PGC 29963, see here for anything else

J101552.6+065726
A magnitude 16(?) spiral galaxy (type Sb?) in
Leo (RA 10 15 52.6, Dec +06 57 26)
Since a possible companion of PGC 29963, see here for anything else

PGC 29980 (=
NGC 3178)
A magnitude 12.7 spiral galaxy (type SA(rs)cd? pec) in Hydra (RA 10 16 09.2, Dec -15 47 28)
For anything else see NGC 3178
Celestial Atlas
PGC 29000 - 29499 ←     PGC Objects: PGC 29500 - 29999     → PGC 30000 - 30499