5 Attachment(s)
Object of the Week January 7, 2018 - A Trio and More in Cetus: NGC 1087, NGC 1090, NGC 1094
Object of the Week January 7, 2018 - A Trio and More in Cetus: NGC 1087, NGC 1090, NGC 1094
Happy New Year! May 2018 bring you many nights of clear, transparent, Moon-less skies with excellent seeing to chase after new deep sky objects as well as to revisit your long-time favorites. For those of us in the United States living through the mind-numbing cold brought on by recent bomb cyclones and polar vortexes may 2018 quickly bring us warmer temperatures.
Constellation: Cetus
NGC 1087, MCG 0-8-9, UGC 2245, PGC 10496
Type: SAB(rs)c
RA: 02h 46m 25.2s
Dec: -00° 29’ 55”
Magnitude: 10.9v
Size: 3.6’ x 2.3’
NGC 1090, MCG 0-8-11, UGC 2247, PGC 10507
Type: Sbc
RA: 2h 46m 34.0s
Dec: -00° 14’ 49”
Magnitude: 11.8v
Size: 3.4’ x 1.5’
NGC 1094, MCG 0-8-15, UGC 2262, PGC 10559
Type: SABa
RA: 2h 47m 27.8s
Dec: -00° 16’ 06”
Magnitude: 12.5v
Size: 1.3’ x 0.9’
During a recent visit to the galaxy M77 in Cetus I noticed on the star chart a nearby grouping of NGC galaxies and decided to give them a go. To the best of my knowledge these three galaxies, NGC 1087, NGC 1090, and NGC 1094, are not part of the M77 (NGC 1068) galaxy cluster; they are just a random line-of-sight grouping. M77 is the dominating member of a small physical group of galaxies, called the M77 group of galaxies, which includes NGC 1055 (type Sb) and NGC 1073 (type SABc), as well as UGC 2161 (DDO 27, type Im), UGC 2275 (DDO 28, type Sm - designating a morphological type between spirals and irregulars) and UGC 2302 (DDO 29, type Sm), and the irregular galaxy UGCA 44 and the SBc barred spiral Markarian 600. NGC 1087 (Sc), NGC 1090 (S-), and NGC 1094 (SABb-) are nearby background galaxies, as their much higher redshift indicates (Info from Burnham, Tully, and the Sky Catalogue 2000.0). For those with very large aperture telescopes you should be able see other fainter galaxies within the ~1° field of view centered on these three galaxies.
Annotated Trio and More Field of View by J.Thommes
Trio Widefield by J.Schuder
The brightest of these three is an intermediate spiral galaxy, NGC 1087, at a magnitude of 10.9v. NGC 1087 was discovered by William Herschel on October 9, 1785. Dreyer’s historical description of the galaxy is “pretty bright, considerably large, a little extended, much brighter middle". De Vaucouleurs Atlas of Galaxy Types uses NGC 1087 an example of galaxy type SAB(rs)c. The description of the galaxy in the Atlas is “This very late-type spiral has a small, knotty bar in a very patchy disk with broad and weak spiral features.”
NGC 1087’s central bar/core is very small with many irregular features in the surrounding disk of material. With the many strange features of NGC 1087, its true nature is still uncertain. It has an extremely small nucleus and a very short stellar bar. Unlike most barred galaxies, the bar apparently has some new star-formation taking place. There is a multiple spiral structure defined more by the dust lanes than by luminous matter. Overall, the disc has a very low surface brightness. NGC 1087’s halo is bright and diffuse with an indistinct, irregular outline and a slightly brighter center. Even though it appears close to NGC 1090, these two galaxies are not interacting and should be considered isolated from one another. A rough distance estimate for NGC 1087 is 80 million light-years, with a diameter of about 86,800 light-years. The Type II Supernova 1995V is the only recorded supernova in NGC 1087.
Attachment 2854
NGC 1087
Attachment 2857
NGC 1087 Revised Shapely-Ames Catalog
Attachment 2858
NGC 1087 SDSS
NGC 1090 was discovered by William Herschel on the same night that he discovered NGC 1087. Dreyer’s historical description of the galaxy is "very faint, pretty large, irregularly round, brighter middle". At a magnitude of 11.8v NGC 1090 is a barred spiral galaxy with a pseudo inner ring. The disc has a very low surface brightness. NGC 1090 is fairly faint, elongated, and has a prominent core that stands out against its fainter halo. The distance to NGC 1090 is approximately 124 million light years and its diameter is about 144,000 light years. The galaxy has been the site of two known supernovae (in 1962 and 1971).
Attachment 2855
NGC 1090
NGC 1094 was discovered by William Herschel on November 7, 1785. Dreyer’s historical description of the galaxy is "very faint, small, round, 2 small (faint) stars to West". At magnitude 12.5v and relatively small at 1.3’ x 0.9’, NGC 1094 is faint, although its core is surprisingly bright and prominent.
Attachment 2856
NGC 1094
Start with this trio of galaxies in Cetus and then go deeper. Give it a go and let us know!
