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NGC 4548 (9,843 of 18,816)


oc gc pln bn dn gx gxcl ast aka lost




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Messier 91

NGC 4548, LEDA 41934, MCG+03-32-075, UGC 7753, Messier 91, II 120, h 1345, GC 3093

RA: 12h 35m 26.58s
Dec: +14° 29′ 45.1″

Con: Coma Berenices
Ch: MSA:725, U2:194, SA:14


(reference key)

Type: galaxy (AGN LINER-type), SBb

Mag: B=11.5, V=13.57

Size: 5.248′ x 4.365′
PA: 150°


Since the publication of the third and final part of Messier's catalgue in 1784, the identity of Messier 91 has been a mystery. The Texan amateur astronomer W. C. Williams has suggested that NGC 4548 is Messier 91, a proposal that has been accepted by Mallas and Kreimer, authors of "The Messier Album". Other possibile candidates include NGC 4571, NGC 4579 & NGC 4689.

Williams, W.C. (1969) Letters [M91 = NGC 4548]. Sky&Telescope, Dec, 376.

Historical observations

William Herschel (c.1784)

Synonyms: H II-120

Discovered in 1784 by William Herschel with an 18.7-inch f/13 speculum telescope. He called it "L, r."

Published comments

Sulentic & Tifft (1973)

The RNGC (Sulentic and Tifft 1973) notes that this is a 11.5 mag galaxy. Their coded description reads BSB,2DIFBDWD ARMS A FEW KNS.

Sandage, A. (1961) The Hubble Atlas of Galaxies

This galaxy appears on page 48 of "The Hubble Atlas of Galaxies" by Allan Sandage (1961, Washington, DC).

Modern observations

Tom Lorenzin

Tom Lorenzin, in the e-version of "1000+ The Amateur Astronomers' Field Guide to Deep Sky Observing", notes: "11.9M; 4.5' x 3.5' extent; soft fuzzy with brighter center; look carefully for very soft halo; it's larger than you think! labelled in Tirion as M-91; Owen Gingerich concurs; !good supernova prospect! see photo at HAG-48."

Brian Skiff

= M91

Lick: bar in pa60, overal pa150.


7cm - mod f modlosfcbr glow @ 50x. halo circ but core elong ~E-W. wk even concen up to core, which is wk-sharply brtr and has *ry texture. BS, 15Apr1993, Anderson Mesa.

15cm - 2'.5x2', even patch w/smlr condensed nuc.

25cm - 180x: fairly br, elong E-W, 2'.5x1'.5. rises smoothly to sm circ core and *ar nuc.

Contemporary observations

Tom Bryant

2008-05-04 22:30:00

Observing site: Pinnacles overlook

Telescope: C-8

[12h 35m 24s, 14 30m 0s] A large, face on Sc, with a bright middle. Burnham: an SBb. Wiki Sky lists this as M 91.

Richard Ford

2012 March 24th, Sat



Sky Conditions:The fainter parts of the Milky Way are barely visible.Haziness only visible on the horizon.Atmosphere stable with little interference.

Instrument:12-inch Dobsonian.

This bright galaxy's oval like structure is clearly seen at a low magnification of 57*and 75*.M91's circular shape with its diffuse spiral arms are on the brink of visiblity.Around the far outskirts of this galaxy I have found some areas of uneven brightness.This galaxy measures 4'* 3'.The central nucleus of this galaxy is brighter compared to the far outskirts of this galaxy.

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