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Thread: Object of the Week January 7, 2018 - A Trio and More in Cetus: NGC 1087, NGC 1090, NGC 1094

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    Member deepskytraveler's Avatar
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    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.

    ngc1087wide.jpg
    NGC 1087

    NGC1087 Revised Shapley-Ames Catalog.jpeg
    NGC 1087 Revised Shapely-Ames Catalog

    NGC1087 SDSS.jpg
    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).

    ngc1090wide.jpg
    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.

    ngc1094wide.jpg
    NGC 1094

    Start with this trio of galaxies in Cetus and then go deeper. Give it a go and let us know!
    Last edited by deepskytraveler; January 9th, 2018 at 04:36 AM.
    Clear Skies,

    Mark Friedman
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  2. #2
    Member Ivan Maly's Avatar
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    I've seen all three plus the companion of 1094 (PGC 10560) in 12" (230x, SQM 21.6).

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    Member Howard B's Avatar
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    Two out of three using my old 20 inch from 1998:

    NGC 1090
    "Fat, fuzzy and relatively faint galaxy near M77. Indistinct edge, no central brightening (and) faint filed star just off the side. In the same field as NGC 1087. 182x"

    NGC 1087
    "Brighter than 1090 but otherwise its twin. Slightly more distinct. NGC's 1094 and 1104 are just out of the 182x field."

    I didn't make a sketch of either one, and this was before the days of the SQM so I can't quantify how dark the sky was - but I'll guess it was around 21.3 to 21.4. I also don't remember why I didn't write a short note about 1094 and 1104 since I obviously saw them nearby, but that gives me a good reason for a long overdue and more detailed look at this group.
    Howard
    28 inch f/4 alt-az Newtonian

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    Can contribute one sketch of NGC 1087 and its companion MCG+00-08-012.

    27", 419x-586x, Seeing III, NELM 6m5+
    NGC1087.jpg
    Clear Skies, uwe
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    Member Steve Gottlieb's Avatar
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    Really nice sketch, Uwe.

    Ron Buta made this quick sketch many years ago using the 36-inch at McDonald Observatory (when conditions weren't satisfactory for research). More recently, he was a co-author of the de Vaucouleurs Atlas of Galaxies), which includes this galaxy.

    NGC 1087.jpg
    Last edited by Steve Gottlieb; January 14th, 2018 at 11:54 PM.
    Steve
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