NGC 864

Historical observations

William Herschel (c.1784)

Synonyms: H III-457

Discovered in 1785 by William Herschel with an 18.7-inch f/13 speculum telescope. He called it "vF, cL, vlbM, milky, preceding pretty bright star and joining."

Published comments

Burnham's Celestial Handbook

Burnham calls it a 12th mag spiral in Cetus, 2.8' across, "extremely faint, considerably large, round, gradually brighter in the middle; 12th mag star S.f. nucleus 35 arcseconds."

Sulentic & Tifft (1973)

The RNGC (Sulentic and Tifft 1973) notes that this is a 12.0 mag galaxy. Their coded description reads E,R,BM.

Photo index

Photo Index by Jim Lucyk: Rev.Shapley-Ames Cat.of Bright Gal. (Sandage,Tammann 1981) p105.

Modern observations

Tom Lorenzin

Tom Lorenzin, in the electronic version of "1000+ The Amateur Astronomers' Field Guide to Deep Sky Observing", notes: "12M; 2.8' diameter; faint and round with 12M star near center (35" SSE of core)."

Steve Coe

Steve Coe, using a 13" f/5.6, notes: "Faint, pretty large, round, somewhat brighter middle, 11 mag star on NE side."

Brian Skiff

Lick: pa indef. spiral arm curls around W side of *.

RSA: * 48" ESE.

53cm photoelectric measures: br * V ~10, next fntr in triangle V ~12.5, fntst V ~13.5.

25cm - a vlosfcbr smudge @ 90x on NW side of m11 *, touching it. quite f, no cen brtning, elong in pa45.

30cm - startlingly br * embedded on E side. 217x shows sm 25" core seemingly in two parts 50" NW of the m10 *. 3'.2x1'.8 in pa60, brtr part 2'.2x1'.5. halo has extensive vf tips. wk broad concen; smooth except for center.

Contemporary observations

Brent Knight

2024 November 22, Friday

Location: Foley - Driveway

Time: 21:30

Telescope: Askar 130PHQ

Limiting magnitude: 5

Sky conditions: SQM-L = 19.40

It lies almost on top of a 10m star that splits the distance between two spiral arms just east of the central region.

The HII regions that I added to my capture (with the help of Alvin's guide) all appear as small, bright patches within the spiral arms. The arms are well defined by these patches, but there appears to be some extended but mostly unresolved halos all around the galaxy. The halo to the south does show an area of multiple condensations that almost seem detached from the main arm.

I see the bar structure pretty clearly, but earlier observers only saw it faintly. The arms seem to attach to this bar at a right angle, but then they extend beyond this for a bit. There does not appear to be much dark material between the two main arms. That area is filled with two additional arms that are distinct, but not as bright as the main ones.