[AZ-Observing] Re: IC 348 or IC 1985
- From: Brian Skiff <bas@xxxxxxxxxx>
- To: az-observing@xxxxxxxxxxxxx
- Date: Thu, 18 Jan 2007 23:15:21 -0700 (MST)
>> Interestingly, IC 348 is also known as IC 1985...
From Harold Corwin's commentaries at the NGC/IC web site:
IC 348 = IC 1985, which see. Dreyer put this into the first IC apparently
without seeing Safford's footnote which reads, "A loose cluster with nebula."
All that appears in the IC description is Safford's "vL, vgbM, pB" rearranged
into the usual brightness-size-concentration order.
Whatever happened, Safford is right -- there is a cluster associated with this
nebulosity. Barnard did not mention the cluster, either, in his discovery
note for IC 1985, though he examined the object both photographically and
visually with the Yerkes 40-inch.
IC 1985 = IC 348. Barnard did not check the first IC before he published
this as a new nebula at the end of his paper on the "Exterior Nebulosities of
the Pleiades." Dreyer apparently did not, either, so the object now has two
IC numbers. See IC 348 for more.
The nebulosity that caught Barnard's eye on a photograph of the Pleiades also
contains a cluster, though the cluster is not visible on either of Barnard's
photographs in his Lick Publications, Vol. 11. (Safford actually did see the
cluster, though Dreyer did not put that into the description for IC 348.)
The region is now, by the way, well-studied particularly for young
low-mass stars. The classic study of the brighter stars was done in
1922 by Gingrich:
1922ApJ....56..139G
GINGRICH C.H.
Astrophys. J., 56, 139-144 (1922)
Parallaxes of stars in the region of BD+31 643.
The bright 'central star' HD 281159 = BD+31 643 is of spectral type B5V,
so is not hot enough to fluoresce the gas, so this strictly a reflection
nebula. The relatively reddish color is due to interestellar
reddening between us and it. HD 281159 has B-V color about 0.8 mag
redder than it would have if it were unobscured.
\Brian
--
See message header for info on list archives or unsubscribing, and please
send personal replies to the author, not the list.
Other related posts:
