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IC 434 (3,866 of 18,816)


oc gc pln bn dn gx gxcl ast aka lost




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IC 434

IC 434, Ced 55n, LBN 954A

RA: 05h 41m 0s
Dec: −02° 27′ 42″

Con: Orion
Ch: MSA:253, U2:226, SA:11

Ref: SIMBAD, Skiff20080430-s

(reference key)

Type: bright nebula (HII region)

Mag: B=?, V=?

Size: ?
PA: ?

Published comments

Pickering, E.C. (1890)

Detection of new nebulae by photography. Annals Harv Coll Obs., 18, 113. Bibcode: [1890AnHar..18..113P]

Photographs taken with the Bache telescope, a photographic 8-inch f/5.5 doublet, covering 10 degrees square, were examined by Mrs M Fleming with a magnifying glass.

Table 1: List of nebulae (p115)

No. 21 "A large nebulosity extending nearly south from zeta Orionis for about 60'. More intense and well marked on the following side, with a semicircular indentation 5' in diameter 30' south of zeta. All good plates of this region show this object, and it has been used here as a test for some time. Attention was called to it in a letter of March 28, 1887, describing copies of some of these photographs sent to the Astrographic Congress of 1887. This object and No. 23 [NGC 2024] are probably the same as those referred to by Admiral Mouchez in ...."

Duncan, J.C. (1921)

Duncan, J. C. (1921) Bright and dark nebulae near zeta Orionis photographed with the 100-inch Hooker telescope. Astrophys. J., 53, 392-396.

Mount Wilson Observatory Annual Reports (1920-1921)

p.254: "IC 434, the Bay Nebula south of zeta Orionis, gives an emission spectrum. This fact was previously determined by Max Wolf (AN v.180,152), who unfortunately concealed the matter by giving a wrong catalogue number - NGC 2023, a nebula which has a continuous spectrum."

p.257: "The bright and dark nebulae near zeta Orionis. The photograph of IC 434 brings out with great prominence the dark cloud, Barnard 33. There is evidence of four distinct types of nebulosity in the region."

Cederblad, S. (1946) [VII/231]

Ced 55n (IC 434)

Position (1900): RA 5 36, Dec - 2 28

Star: 2 1338 (Mp=1.58, V=1.91, SpT=B0n, B)

Spectrum of nebula: continuous and emission spectrum (observed)

Classification: Neb associated with mainly one star (which may be multiple) - Nebula with bright rim (eg. IC 434)

Size: 60'x10'

Notes: "Ced 55 n = IC 434. Disc. Pickering 1890 (557). WP 67. (78, 87, 92, 215, 216, 235, 282, 294, 412, 416, 620, 630 Pl 34, 717, 724, 820). R. This is the bright rim extending southwards from {zet} Orionis = -2 1338 = HD 37742,3 = Boss 7089. Ced 55: The Orion region. History and bibliography: (118, 119, 186, 188, 191, 276, 352). The nebulous groundwork and the exterior nebulosities: (20, 21, 26, 53, 58, 78, 142, 143, 186, 191, 206, 207, 278, 279, 281, 282, 289, 305, 312, 438, 480, 519, 540. 541, 593, 594, 595, 620, 625, 628, 630 Pl 34, 663, 675, 715, 726 No 41, 769, 782, 802, 818). R. It is shown on several photographs, e.g. (630) Pl 34, that the whole region of the constellation Orion is filled up by vast masses of nebulosity. As is well known, there are several condensation which seem to stand out from the general background, and which have been separately discovered and studied. Such subnebulae, will be individually discussed below. Taken as a whole, No 55 of the catalogue should be classified as C. 2 in addition to the separate classes of the subnebulae."

Lynds, B.T. (1962)

Lynds, B.T. (1962) Catalogue of dark nebulae. Astrophys.J.Suppl.Ser. 7, 1-52. [also: computer datafile: VII/7A]

Photo index

Photo Index by Jim Lucyk: Sky&Tel. 9/87 p254.

Modern observations

Steve Coe

Steve Coe (Glendale, Arizona, USA) observing with a 17.5-inch f/4.5, writes in The Webb Society Nebulae and Clusters Section Report No. 10, July 1992: "This much photographed region includes the Horsehead Nebula (B.33) IC 434 is a faint streamer of emission nebulosity to the south of Zeta Ori. I have seen the Horsehead in the 17.5-inch f/4.5 at x125; with averted vision some light and dark detail could be seen but it was tough. The Horsehead outline is small, maybe the size of the Ring Nebula."

Forbes, Le (1993)

Le Forbes (Stoke, St. Mary Bourne, Hampshire) observing from Puimichel, France, writes in The Webb Society Nebulae and Clusters Section Report No. 11, January 1993: "Edge of nebulosity (IC 434) cuts the field vertically in half. The Horsehead itself (B.33) fills one-sixth of the field on the right-hand side and is visible only after tapping the tube, and then becomes clear. Shape of the dark nebula sharp and detailed, the bright nebula fainter and not sharp beyond the dark region. (42-inch, x185/x310)"

Bushnall, Darren (1993)

Darren Bushnall (Hartlepool, Cleveland) observing with a 8.5-inch f/6, writes in The Webb Society Nebulae and Clusters Section Report No. 11, January 1993: "IC 434 was visible as a moderately bright haze using an H-beta filter; about 35' in length. B.33 visible as a small, irregular patch jutting in the side of IC 434."

Clark, R.N. (1990)

See also "Visual Astronomy of the Deep Sky" by Roger N. Clark (1990, Sky Publishing Corporation) page 106.

Steve Coe

Steve Coe, using a 13" f/5.6, notes: " and B 33 is a much-photographed region that includes the Horsehead Nebula (B 33). IC 434 is a faint streamer of emission nebula that is south of Zeta Ori. The Horsehead is a dark nebula that blots out a portion of IC 434 in the shape of a mare's head. I have seen the Horsehead in the 17.5 inch scope at 125X. With averted vision some light and dark detail could be seen, but it was tough. The Horsehead outline is small, maybe the size of the Ring Nebula."

Honeycutt, Eric (IAAC)

Observer: Eric Honeycutt Your skills: Intermediate (some years) Date/time of observation: 10/14 -15; 0333 EDT Location of site: Bladen Lakes State Forest (Lat 35, Elev 400+) Site classification: Rural Sky darkness: 6.9 Limiting magnitude Seeing: 5 10-1 Seeing Scale (1 best) Moon presence: None - moon not in sky Instrument: 22", f/4.1, Dob Magnification: 74x, 118x, 216x - UHC Filter(s): Object(s): IC 434 - The Horsehead Nebula Category: Emission nebula. Class: Dark Nebula/E Nebula Constellation: Ori Data: mag -- size

Description: After getting to the precise position below Zeta Orionis, I used a 22 Nagler with a UHC filter to id the Horsehead. After a few minutes, the horsehead shape popped right out. Once obtained, it stuck right out as a direct vision object. Much larger than I anticipated. Still very faint by most standards but it is relatively easy once you know where it is within your field. There is no need for a H-beta filter or even a O-III at this aperture and dark skies. The snoot of the horse was also visible but with averted vision. Best view was with a 35 Panoptic at 74x with a UHC. I did not detect the Horsehead or the background nebula (IC 434) with a 12 Nagler and a O-III. Field was just too dark. Need to try this one under mtn skies for even higher transparency.

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