[vsnet-alert 3630] Re: Possible outburst of nova in 1914

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

At 01:04 PM 10/26/99 +0900, you wrote:
>Dear colleagues,
>
>I am Seiichi Yoshida, working on the MISAO Project.
>
>We discovered a new variable star very near by V949 Sgr, a nova in
>1914. Maybe it is the outburst of a recurrent nova, or maybe the nova
>in 1914 was just a red variable star. Further observations are
>encouraged.
>
>The star is named MisV0508. It is at R.A.=18h41m03s.10,
>Decl.=-28o09'35".6 (2000.0) and identified with GSC6870.1383 =
>USNO-A2.0_0600.36532866 = IRAS 18379-2812. It was detected by the PIXY
>system as one of the candidates of new variable stars from unfiltered
>CCD images taken by KenIchi Kadota, Ageo City, Saitama, Japan, with
>0.16-m f/3.3 reflector, then confirmed by Seiichi Yoshida as a real
>new variable star. It was 11.5 mag on July 15.59 and 13.3 mag on
>Sept. 23.44 (UT). The magnitude is based on a preliminary V magnitude
>calculated from R and B magnitude in the USNO-A1.0 based on Taichi
>Kato's equation:
>  V = R + 0.375 (B - R)
>
>And we found that this object and V949 Sgr, a nova in 1914, are at the
>same position within 12 arcsec.
>
Hii All,
        The GCVS position for V949 Sgr is only approximate, being derived the
work published in the Union Observatory Circulars (R.T.A. Innes, 1917 UOC
37,202).
High precision astrometry of variable stars was rarely done, from what I
have seen
in the UOCs. In fact V949 Sgr was observed on only three occasions between
1914 July 16
and July 25. No spectroscopic information was obtained, so the
classification as a
nova must be considered dubious.
        GSC 6870.01383 is relatively bright at m = 12.68, but the corresponding
ISNO-A2.0 star is very faint at mB = 18.8. For the moment I disregard the V
mag.       as the red plate would have been exposed at a different time, and
could distort
the derived V mag.   I have checked the photo finder chart provided by Duerbeck.
He could not identify V949 Sgr, but it I can identify GSC 6870.01383. It is very
faint, consistent with  mB = 18.8.  There is no sign of a 12.7 mag. star
near this
spot.
        In view of these facts, that GSC 6870.01383 shows variations from 12.68
to 18.8B, and is also a very red star (IRAS source), I surmise that V949 Sgr
is the
same star. In view of its large amplitude it is a probable Mira variable. 

REFERENCE:
Duerbeck, H.W., 1987, Space Science Reviews 45/1+2, p108.

Regards,
/Mati

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