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IC 4684 (14,952 of 18,816)

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IC 4684

IC 4684, Ced 154b, DG 148, Bernes 8, LBN 34, Magakian 750, VDB 115

RA: 18h 09m 9s
Dec: −23° 26′ 5″

Con: Sagittarius
Ch: MSA:1392, U2:339, SA:22

Ref: [2003A&A...399..141M]

(reference key)

Type: reflection nebula

Mag: B=?, V=?

Size: 3′ x 3′
PA: ?

History and Accurate Positions for the NGC/IC Objects (Corwin 2004)

IC 4684. See IC 4681.

Historical observations

Barnard, E.E

This nebula was discovered photographically by Barnard. He described it as "a small nebula or a nebulous star."

Published comments

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

Ced 154b (IC 4684)

Position (1900): RA 18 3, Dec - 23 27

Star: -23 13974 (Mp=9.78, V=9.64, SpT=B9)

Spectrum of nebula: continuous spectrum (inferred from sp.t. of illuminating star)

Classification: Neb associated with mainly one star (which may be multiple) - star surrounded by a neb envelope without conspicuous structure (eg. lambda Scorpii)

Size: (not given)

Notes: "Ced 154 The group of nebulous stars following M 8. R. There has been some confusion in the literature as to the proper identification of these objects. Ced 154 b = IC 4684 = -23 13974 = HD 167852 nebulous. Disc. Barnard 1908 (85). R. (88) Pl 52 gives the star as -23 13983, which is seen to be erroneous from the plate coordinates of the star. Probably -23 13983 in Seares' and Hubble's list (664) also refers to -23 13974, as it is very improbable that this nebulous star should have been excluded."

Gum, C.S. (1955)

Gum, C.S. (1955) A survey of southern HII regions. Mem.RAS, 67. [1955MmRAS..67..155G]

notes that Gum 75 is "Almost joined to Gum 72 (M8). The separation from M8 appears to be due to a lane of foreground obscuration. A number of 'nebulous' stars and reference to large faint patches of nebulosity corresponding to bright condensations in this region are given by IC 1274, 1275, 4681, 4684 and 4685 (Nos. 154b, c, d, e and f in the Catalogue of Cederblad)."

Dorschner & Gürtler (1963)

Untersuchungen uber Reflexionsnebel.

DG 148

= IC 4684, Ced 154b

Pos (1950.0) 18:06.0, −23:27

Size: 3x3 (blue), 2x2 (red).

Lynds, B.T. (1965)

Beverly Lynds (Astrophysical Journal Supplement, No 105, 1965) in her Catalogue of Bright Nebulae, notes that this nebula is moderately bright, more prominent on the blue POSS plate has a maximum size of 3' x 2'.

Bernes, C. (1977)

Bernes, C. (1977) A catalogue of bright nebulosities in opaque dust clouds.

Bernes 8 = IC 4684 = VdB 115

This reflection nebula is catalogued as Bernes 8, a 2'x3' bluish reflection nebula, also known as vdB 115.

Magakian T. Yu. (2003)

= DG 148, [RK68] 84, VdB 115, Bernes 8, IC4684, GN 18.06.1, Ced 154b

Class: C (reflection neb)

Comments: double star

Modern observations

Bahr-Vollrath, Gerd (1992)

(Noosa Heads, Queensland, Australia) observing with an 8-inch f/12 SCT, writes in The Webb Society Nebulae and Clusters Section Report No. 10, July 1992: " [NGC 6559, IC 1274, IC 1275, IC 4684, IC 4685] This complex of faint nebulosity lies about one degree east of M8, and deep photographs reveal that it seems connected to its more prominent neighbour. Low magnifications and a UHC filter were necessary to see indistinct faint patches of nebulosity, most of which seem associated with groups of stars."

Brian Skiff

15cm - nothing but nice dbl *, res @ 50x. BS, 10Dec1990, Anderson Mesa.

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