[vsnet-chat 4928] Re: Novae? IC 1292 and IC 2189

["Mati Morel" <morel@ozemail.com.au>]

----- Original Message -----
From: Brian Skiff <bas@lowell.edu>
To: <ahenden@nofs.navy.mil>; <gerard@simbad.u-strasbg.fr>;
<hgcjr@ipac.caltech.edu>; <mhazen@cfa.harvard.edu>; <samus@sai.msu.ru>;
<vsnet-chat@kusastro.kyoto-u.ac.jp>
Sent: Monday, November 26, 2001 2:16 PM
Subject: [vsnet-chat 4927] Novae? IC 1292 and IC 2189


>      Out curiosity this evening I went through the two IC catalogues to
> make a list of nebulae reported by Williamina Fleming.  A few dozen
objects
> are involved, and all but two appear to be accounted for in one way or
another
> in modern lists.  Most are bona fide planetary nebulae, with a few
Wolf-Rayet
> stars and galactic novae included, plus compact HII regions in the
Magellanic
> Clouds.
>      Of the two unidentified ones, the first is IC 1292.  This was
reported in
> 1894AN....137...71F.  The remarks indicate that the object is offset from
> CD-27 13151 by -0s.6 in RA and +1'.6 in Dec.  There is no nebula at this
> position, nor any star brighter than about mag. 14.  She mentions also
that
> E.C. Pickering observed the object with a visual spectroscope on 1894 Oct
18,
> confirming its nebular nature.  No magnitude is given with the original
report.
>      Fleming also says that the object could be CD-27 13150, despite the
large
> position difference, but that the CD star was not visible on the plate(s)
> involved.  The CD place for this entry, however, corresponds closely to a
> mag. 12.5-13 star, and it doesn't seem unreasonable to assume this is the
CD
> star, since stars this faint occur commonly elsewhere in the catalogue.
>      Using a modern position for CD-27 13151, which is GSC 6867-1486 at:
> 18 44 46.4  -27 49 54 (2000), the nebula is placed at:  18 44 45.8  -27 48
18
> (2000), presumably uncertain by a few tenths of an arcminute.
>      Given the description, and the object's absence from sky survey
images
> (at least nothing bright here), it is easy to suspect this was an ordinary
> galactic nova caught in its nebular phase by both Fleming and Pickering.
> An emission-line object in this region would have been picked up in a
modern
> survey; a search in VizieR reveals nothing unusual nearby.  The date of
the
> objective-prism plate is not given, but must be from the austral
winter/spring
> of 1894.  One can estimate that at the time of Pickering's October 1894
> observation the object was no fainter than about mag. 12 since he was able
see
> at least the [OIII] lines with a visual spectroscope using the Harvard
15-inch
> refractor.
>      Did a mag. 8 or 9 nova near phi Sgr get overlooked sometime from July
to
> to October of 1894?
>
Hi,
    I find it more plausible to identify CD-27 13150 with GSC 6867.02177
(m=11.3) at
(2000) 18:44:41.1  -27:44:45.  The faint star mentioned by Brian is GSC
6867.00102 (m=12.8),
more than  1' southwards. The CD position is in error, but this is not
uncommon. It is true that the
CD does dip as low as 12th mag, but I tend to very suspicious if it is at
the expense of a nearby,
much brighter star.    GSC 6867.02177 is barely visible on my copy of the
Falkauer Atlas, at blue mag.
13.0.  This indicates a very red star, and probably would have registered
rather poorly on the blue-sensitive
plates used at Harvard, making identification difficult.
Regards,
Mati

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