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Type: galaxy (Seyfert), S0
Mag: B=11.1, V=?
Size: 6.456′ x 3.162′
NGC 5866 may be Messier 102. There is a long history, particularly in France, of taking this galaxy to be one of those found by Mechain (in 1781 in this case), and verified by Messier. For M102, however, Messier's verification is limited to a penciled-in position in his own copy of his list published in Connaissance des Temps for 1783/4. That position is "14.40" and "56", i.e. 14h 40m, +56d. There is no equinox given, but we can assume it to be 1780 without too much error. For comparison, the accurate position for N5866 precesses back to 15 00.5, +56 37 for 1780. For M101 (= NGC 5457, which see), the other usual choice for M102, the precessed accurate position is 13 55.4, +55 25.
It's clear than neither galaxy fits the written-in position in Messier's list. But some evidence in favor of both objects has been found. This has been collected in a Web document by Hartmut Frommert on the SEDS site:
To summarize: Messier's working maps were laid out in grids of five degrees in both RA and Dec. This makes it possible that the written-in position was hastily read off his map with a 20 minute and 1 degree error for "15.00" and "57"; this would make the object NGC 5866.
The case for M102 being M101 is, in my mind, somewhat more convincing. Quite simply, Mechain wrote in 1783 to the editor of the Berliner Jahrbuch that the observation of M102 is nothing more than a repeated observation of M101. This letter still exists and was published in 1947 by Helen Sawyer.
N5866 could certainly have been seen by both Messier and Mechain; other of Messier's objects are fainter (e.g. M92). However, Mechain's description is not very helpful: "Nebula between the stars Omicron [this should read "Theta"] Bootis and Iota Draconis; it is very faint; near it is a star of sixth magnitude." Aside from the description of the position, this could fit either galaxy. "Omicron" is almost certainly a typesetting error -- a lower case "Theta", with the top loop almost closed, looks quite a bit like a lower case "omicron."
In the end, the evidence is contradictory, and the true identity of M102 may be lost forever. As I said, however, I lean toward the identity with M101.
Synonyms: H I-215
Discovered in 1788 by William Herschel with an 18.7-inch f/13 speculum telescope. He called it "vB, cL, E, follows 2 stars."
In the 5th edition of Webb's Celestial Objects for Common Telescopes it is described as "Herschel, very bright. D'Arrest, 90x30 arcseconds."
The RNGC (Sulentic and Tifft 1973) notes that this is a 11.5 mag galaxy. Their coded description reads BE,EL,BM,DIFHALO.
G. de Vaucouleurs ("Galaxies and the Universe", Chapter 14 - Nearby Groups of Galaxies) notes that the five brightest members of the NGC 5866 Group are NGC 5866, NGC 5907, NGC 5879, NGC 5905 & NGC 5908.
This galaxy appears on page 6 of "The Hubble Atlas of Galaxies" by Allan Sandage (1961, Washington, DC).
Doig, P. (1925) Notes on the nebulae and clusters in Webb's 'Celestial Objects for Common Telescopes' (Sixth edition, Vol.ii). Part I. M.N.R.A.S., 35(5), 159.
by Jim Lucyk: Sky&Tel. 7/73 p13, Sky&Tel. 7/80 p82 (sketch), Vehrenberg's Atlas of DS Splendors (3ed) p156, Hubble Atl.of Gal. (Sandage 1961) p6, Field Guide to Stars & Planets (Menzel, 1964) p132.
"nebula, much elongated at 135°, 2.0' x 0.7'; spiral?"
Bailey, S.I. (1908) A catalogue of bright stars and nebulae. Ann.Harv.Coll.Obs., 60(8), 199.
Houston notes that this is one of a little group of galaxies in southern Draco, near the east of the handle of the Big Dipper. It is the brightest in the group and at visual magnitude 9.7 is easily seen in a 4-inch refractor.
Tom Lorenzin, in the e-version of "1000+ The Amateur Astronomers' Field Guide to Deep Sky Observing", notes: "11.1M; 3' x 1' extent; NW-SE-oriented lens shape; bracketed N-S with two 12M stars in W sector; see photo at HAG-6; !good supernova prospect! bright star 10' to SW is 7.5M SAO 29401."
Your skills: Intermediate; Date and UT of Observation: 1997-08-02/03, 02:00 UT; Location: Savoy, MA, USA (42N, elev 700m); Site classification: rural; Limiting magnitude: 7.3 (zenith); Seeing: 8 of 10 - quite good, occasional haze and lightning!; Moon up: no; Instrument: 20" f/5 Tectron truss-tube dob Newtonian reflector; Magnification: 70x, 210x, 420x; Filters used: None; Object: M102? (ngc5866 - The Spindle Galaxy); Description:
Fearing a cloud-out tonight, I whipped the truss-tube monster over to Draco, just to be sure I'd see SOMETHING worth logging. (As it happened, the Summer Star Party avoided Stellafane's watery fate the entire night... But why take chances!) The Mystery Messier's halo was clearly elongated NE-SW at 70x, spanning what appeared to be more like 10' length than 5'. The core was very much brighter than the surrounding pearly haze, seemed somewhat off-axis in its N-S elongation, and appeared distinctly rectangular at both 70x and 210x! A strong dark lane SE of the core was best seen at lower powers than 420x, curving very gracefully to the S and then the W, separating the S section of the halo from the core. A smaller and more mottled dark lane (?) was noted W of the core, with a still smaller but wider branch lane heading E to within 30" of the core. At 210x and 420x, the halo stretched irregularly perhaps 6' to the NE, and 5' to the SW. Above and below the core, the halo was very diffuse and no larger than 2' in either direction.
Your skills: Advanced (many years); Date/time of observation: 02/Aug/1998 0640UT; Location of site: Palisades-Dows Observatory Nr Cedar Rapids, Iowa (Lat , Elev ); Site classification: Rural; Sky darkness: 6.0 Limiting magnitude; Seeing: 7 1-10 Seeing Scale (10 best); Moon presence: None - moon not in sky; Instrument: 10" Starsplitter Newtonian; Magnification: x152;
Description: Very bright with an extremely bright central condensation. Very elongated. The northern edge appeared distinctly sharper than the southern one, though no dark lane is present.
which does not = M102
NGC: pa146., Lick: pa130., Hartung: pa125., Hubble: pa125., UGC: pa128.
POSS: * 1'.6 in pa335; 1'.5 in pa235.
6cm - pretty easy. elong seen. * NW noted. Roof.
15cm - pretty br, SE of m11 *. vf * on SW. pa120, 2'x1'. core rounder, much brtr. Roof.
- vbr, elong SE-NW, 2'x0'.75, lentic outline. maj axis has br streak running through it. core grows smoothly brtr to sm non*ar nuc. two br *s: m11 NW, m12.5 WSW. BS, 6Jun1981, Slate Mtn.
25cm - pa130, 3'x0'.75. halo much fntr on NW side, puts brtst part in center, but core much lgr & brtr SE. N flank seems flattened, S side has dome-like cen bulge a la UFO. Roof.
- 190x: hisfcbr, grows smoothly brtr to center. center br but only vf *ar nuc. m13.5 * on W, plus others from 15cm obs. BS, 6Jun1981, Slate Mtn.
30cm - pretty. vbr, big. elong in pa120 overall, 2'.8x1'.2. core "winged" with wings on opposite edges of nebula, this giving core an apparent pa of 110 or so. no nuc. two br *s assoc: NW & SW ~2'. Roof.
A 10th mag elliptical galaxy with an oval disk. It can be seen in a finder. Admiral Smythe incorrectly suggested that this galaxy is the "missing" M102 -- a long-forgotten letter by Mechain showed that M102 was identical with M101.
Observing site: Little Bennett Regional Park
[15h 6m 30s, 55° 46m 0s] A bright galaxy, spiral, mottled, almost edge on. Not a bright nucleus. (Edge on with a dust lane. Overexposed by WikiSky)
The Messier objects
The Bennett objects
The Caldwell list
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