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NGC 3109
ESO499-G036
RA 10:03:06
Dec -26°09.5'
Galaxy |
h: "very faint, very large, 12' long, 2'
broad, a little brighter in the middle, pos of axis = 82.3 degrees." During
the next sweep, he described it as "faint, very large, very much elongated,
10' long, 90 arcseconds broad, place of a 12th mag star in or near the centre."
In his comments on NGC 134, NGC 1532 and NGC 3109 he writes: "These figures
exhibit elliptical nebulae normal in their character - that is to say, in which,
as the condensation increases towards the middle, the ellipticity of the strata
diminishes, or in which the interior and denser portions are obviously more
nearly spherical than the exterior and rarer. A great number of such nebulae, of
every variety of ellipticity and central condensation are figured in my Northern
Catalogue. Regarding the spherical as only a particular case of the elliptical
form, and a stellar nucleus as only the extreme stage of condensation, at least
nine-tenths of the whole nebulous contents of the heavens will be found to
belong to this class - so that, as regards a low and a structure, the induction
which refers them as a class to the operation of similar causes, and assumes the
prevalence within them of similar dynamical conditions, is most full and
satisfactory. To abstain altogether from speculation as to what may be the
nature of those causes and conditions, and to refuse all attempts to reconcile
the phenomena of so large and so definite a class of cosmical existences with
mechanical laws taken in their most general acceptation, would be to err on the
side of excessive caution, and unphilosophical timidity. The time is clearly
arrived for attempting to form some conception at least of the possibility of
such a system being either held in a state of permanent equilibrium, or of
progressing through a series of regular and normal changes, resulting either in
periodical restorations of a former state, or in some final consummation."
Houston calls this "one of [my] favourite
galaxies." It is a long, spindle-shaped irregular galaxy about half a moon
diameter long. Its ends appear squared off, and while the surface brightness is
rather uniform, Houston sees a strong hint of "curdling" with his
4-inch Clark.
Tom Lorenzin: "11.2M; 11' x 2' extent;
extremely faint, large slash with axis oriented E-W; no center condensation, but
12M star near center"
Steve Coe (1992, The Deep-Sky Observer, Webb
Society, Issue 1) observing with a 17.5-inch f/4.5 at 100x notes: "faint,
very elongated, stellar nucleus, averted vision shows some detail."
Other names: "E499-36,D236,UA194".
Inclination: (face-on, in degrees) 81 Total photoelectric blue mag 10.39
Logarithm of the angular diameter D25 (arcminutes) 2.28 Blue photographic
magnitude 10.39 This galaxy is included in a sample of galaxies with velocity
less than 500km/s with respect to the centroid of the Local Group. [Nearby
Galaxies. Schmidt K.-H., Priebe A., Boller T. (Astron. Nachr. 314, 371 (1993))] |
