[vsnet-chat 4927] Novae? IC 1292 and IC 2189

[Brian Skiff <bas@lowell.edu>]

     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?


     The second unidentifiable object is IC 2189 in Canis Minor, whose position
is given in 1895AN....138..175F as:  7 19.5 +09 07 (1900) = 7 24 57  +08 55.3
(2000) [uncertainty perhaps 1'-2'?].  No magnitude is given, and the only
comment is that it was found on a plate taken in 1895 (no more specific date,
but presumably early in the calendar year) with the 8-inch Draper telescope in
Cambridge MA.
     Again there is no nebula here, nor any bright star, and SIMBAD/VizieR
shows nothing unusual nearby.  Unlike IC 1292 there is no more information to
go on.  But I again feel this is a good candidate for a nova caught in the
nebular phase.

\Brian

------------------------------------------------------------------------------
source papers:

1894AN....137...71F
  FLEMING W.P.
  Astron. Nach., 137, 71-74 (1894)
  Stars having peculiar spectra.  New variable stars in Lupus, Pavo, and
    Microscopium.

1985AN....138..175F
  FLEMING W.P.
  Astron. Nach., 138, 175-180 (1895)
  Stars having peculiar spectra.  Eleven new variable stars.

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