Steve Gottlieb
January 25th, 2016, 03:03 AM
Object of the Week, 24 January 2016
VV 169 = Arp 327 = HCG 34
RA: 05h 21m 47.4s
Dec: +06° 40' 37"
Type: Galaxy Chain (quartet)
Size: 1.25' length
Light travel time: ~425 million years
Boris Voronstov-Velyaminov first catalogued this group in his 1959 Atlas and Catalogue of Interacting Galaxies (https://ned.ipac.caltech.edu/level5/VV_Cat/frames.html). He labeled four galaxies in a chain (a, b, c, d) with NGC 1875 = VV 169a.
1977
Halton Arp followed suit and included Arp 327 in the category of "Chains of Galaxies" in his 1966 Atlas of Peculiar Galaxies (https://ned.ipac.caltech.edu/level5/Arp/frames.html)
1978
Finally, Paul Hickson included it in his 1982 paper Systematic Properties of Compact Groups of Galaxies (http://ads.ari.uni-heidelberg.de/cgi-bin/nph-journal_query?volume=255&plate_select=NO&page=382&plate=&cover=&journal=ApJ..). HCG 34 is the only group in Orion!
1979
The elliptical galaxy NGC 1875 (RC3 classifies it as a possible lenticular) is the dominant member. It was missed by the Herschels and discovered by Albert Marth using William Lassell's 48" f/9.4 fork-mounted speculum-reflector in 1863. I'm guessing a 10" is close to the minimum aperture to reveal this galaxy -- perhaps forum members can test this theory! Here are 3 of my own observations, the last of course on Jimi's scope --
NGC 1875 = HCG 34A = VV 169a
17.5"(220x): faint, round, 20" diameter, very faint stellar nucleus. Located 1.0' E of a mag 13.5 star.
24" (375x): moderately bright, fairly small, round, 0.4' diameter, well concentrated with a small brighter core. A mag 13 star lies 1' W and a mag 16 star is just 0.4' W of center.
48" (488x): bright, round, 30" diameter, brighter core.
Three much fainter galaxies extend in a short string to the southeast (in order from NGC 1875: HCG 34D/34C/34B). Hickson measured total B magnitudes of 18.4, 17.3 and 17.6, respectively, for the trio. I was able to glimpse HCG 34B and 34C in my 24" though they were just dim blurs, and I missed the virtually stellar HCG 34D.
HCG 34B = VV 169c
24" (375x): extremely faint, very small, slightly elongated, ~10" diameter.
48" (488x): faint, very small, elongated 2:1 ~N-S, 20"x10".
HCG 34C = VV 169b
24" (375x): extremely faint and small, round, ~6" diameter.
48" (488x): faint, very small, slightly elongated E-W, 12"x8".
HCG 34D = VV 169d
48" (488x): extremely faint and small, round, 6" diameter.
1976
Although Hickson only included 4 members in HCG 34, you'll notice LEDA 1306245 (Megastar labels it MAC 0521+0643B) labeled in the image just above (3.5' NE of NGC 1875). It shares a similar redshift with the quartet, so it really should have been included as a 5th member. In fact, if you miss B, C and D, go after for this galaxy -- I found it slightly easier!
This is a challenging OOTW that should be attempted on a transparent night, but whether you're successful or not with the fainter members,
GIVE IT A GO AND LET US KNOW!
VV 169 = Arp 327 = HCG 34
RA: 05h 21m 47.4s
Dec: +06° 40' 37"
Type: Galaxy Chain (quartet)
Size: 1.25' length
Light travel time: ~425 million years
Boris Voronstov-Velyaminov first catalogued this group in his 1959 Atlas and Catalogue of Interacting Galaxies (https://ned.ipac.caltech.edu/level5/VV_Cat/frames.html). He labeled four galaxies in a chain (a, b, c, d) with NGC 1875 = VV 169a.
1977
Halton Arp followed suit and included Arp 327 in the category of "Chains of Galaxies" in his 1966 Atlas of Peculiar Galaxies (https://ned.ipac.caltech.edu/level5/Arp/frames.html)
1978
Finally, Paul Hickson included it in his 1982 paper Systematic Properties of Compact Groups of Galaxies (http://ads.ari.uni-heidelberg.de/cgi-bin/nph-journal_query?volume=255&plate_select=NO&page=382&plate=&cover=&journal=ApJ..). HCG 34 is the only group in Orion!
1979
The elliptical galaxy NGC 1875 (RC3 classifies it as a possible lenticular) is the dominant member. It was missed by the Herschels and discovered by Albert Marth using William Lassell's 48" f/9.4 fork-mounted speculum-reflector in 1863. I'm guessing a 10" is close to the minimum aperture to reveal this galaxy -- perhaps forum members can test this theory! Here are 3 of my own observations, the last of course on Jimi's scope --
NGC 1875 = HCG 34A = VV 169a
17.5"(220x): faint, round, 20" diameter, very faint stellar nucleus. Located 1.0' E of a mag 13.5 star.
24" (375x): moderately bright, fairly small, round, 0.4' diameter, well concentrated with a small brighter core. A mag 13 star lies 1' W and a mag 16 star is just 0.4' W of center.
48" (488x): bright, round, 30" diameter, brighter core.
Three much fainter galaxies extend in a short string to the southeast (in order from NGC 1875: HCG 34D/34C/34B). Hickson measured total B magnitudes of 18.4, 17.3 and 17.6, respectively, for the trio. I was able to glimpse HCG 34B and 34C in my 24" though they were just dim blurs, and I missed the virtually stellar HCG 34D.
HCG 34B = VV 169c
24" (375x): extremely faint, very small, slightly elongated, ~10" diameter.
48" (488x): faint, very small, elongated 2:1 ~N-S, 20"x10".
HCG 34C = VV 169b
24" (375x): extremely faint and small, round, ~6" diameter.
48" (488x): faint, very small, slightly elongated E-W, 12"x8".
HCG 34D = VV 169d
48" (488x): extremely faint and small, round, 6" diameter.
1976
Although Hickson only included 4 members in HCG 34, you'll notice LEDA 1306245 (Megastar labels it MAC 0521+0643B) labeled in the image just above (3.5' NE of NGC 1875). It shares a similar redshift with the quartet, so it really should have been included as a 5th member. In fact, if you miss B, C and D, go after for this galaxy -- I found it slightly easier!
This is a challenging OOTW that should be attempted on a transparent night, but whether you're successful or not with the fainter members,
GIVE IT A GO AND LET US KNOW!