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RA: 18h 09m 17.6s
Dec: −23° 59′ 16.1″
Ch: MSA:1392, U2:339, SA:22
Ref: SIMBAD, Corwin (2004)
Type: bright nebula
Mag: B=?, V=?
This nebula was discovered photographically by Barnard. He described it as "7.5 mag star in large diffuse nebulosity."
Ced 154c (IC 4685)
Position (1900): RA 18 3.2, Dec - 24 1
Star: -24 13962 (Mp=7.38, V=7.20, SpT=B0)
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 c = IC 4685 = -24 13962 = HD 165921 = Boss 24732. Disc. Barnard 1908 (85)."
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)." This bright emission nebula is part of Bernes 7, a complex consisting of NGC 6559, IC 1274, IC 1275 and IC 4685.
Bernes, C. (1977) A catalogue of bright nebulosities in opaque dust clouds.
Bernes 7 = NGC 6559 / IC 1274 / IC 1275 / IC 4685.
(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."
The Messier objects
The Bennett objects
The Caldwell list
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