COMMISSION 27 OF THE I.A.U.
                 INFORMATION BULLETIN ON VARIABLE STARS
                              Number 2971

                                                         Konkoly Observatory
                                                         Budapest
                                                         29 December 1986

                                                         HU ISSN 0374 - 0676


                 V358 Lyr - A WZ SAGITTAE STAR ?

Andronov (1986) kindly informed us that according to Galkina and
Shugarov (1985) this object discovered by Hoffmeister is invisible on all
plates of the Moscow collection (period: JD 2434112 ... 2445264). We
therefore examined this star on all available Sonneberg plates (about 310
plates of the period JD 243 8551 ... 244 6476) and found that the star is
only visible on 3 plates. The dates are given in the following table:

Plate        1965        JD        m_pg

Te_4 4601    Jun 25    2438937    [14.5
Te_4 4609    Jun 29       8941     13.27
GC 1387      Aug  4       8977     16.42
GC 1388      Aug 19       8992     17.31
GC 1389      Aug 23        8996   [18.5

  On the prints of the Palomar Sky Survey the object is invisible [21m.
The magnitudes of the comparison stars were determined by fitting to
the sequence of MV Lyr (Andronov and Shugarov, 1982), see Fig. 1 and the
following table.

star     m_pg      star     m_pg

 a       13.22      e       16.38
 b       13.81      f       16.53
 c       14.39      g       18.1:
 d       15.21

 The light curve, tentatively interpolated between the few measured points,
is given in Fig. 2. It reminds one of a fast nova. According to Duerbeck
(1981) the absolute magnitude of a fast nova at maximum is about -9.4,
The galactic co-ordinates of the object are:

l= 72.6deg     b =+16.5deg

   Taking the apparent magnitude of V358 Lyr to be 13m.0 at the top of the
maximum and assuming the interstellar extinction to be 0.4 mag (Sharov 1963),
we get a distance of r = 250 kpc from the Sun and  z=~71 kpc from the
galactic plane.

                          [FIGURE 1]
                          [FIGURE 2]

   It is true that novae are sometimes situated far away from their parent
galaxy (Wenzel and Meinunger, 1978 and Richter, 1981), but these values of r
and z are rather large. They could, however, be reduced to some extent if the
interstellar extinction should turn out to be larger than estimated.
   But there is still a chance for V358 Lyr to be a WZ Sagittae star whose
maximum brightness is expected to be about +2M. That this is by no means
implausible can be shown by the fact that the few observed points in Fig. 2
can be almost exactly fitted into the light curve of WZ Sge itself (Ortolani
et al. 1980).
   Thus the question whether V358 Lyr is a classical nova or a WZ Sagittae
type object remains open. There are, however, some points in favour of the WZ
Sagittae interpretation.


                           G. A. RICHTER

                     Zentralinstitut fur Astrophysik
                        Sternwarte Sonneberg
                             Sonneberg
                             DDR - 6400



References:

Andronov, I.L., 1986, private communication
Andronov, I.L., Shugarov, S.Yu., 1982, Astron. Tsirk No. 1218 [BIBCODE 1982ATsir1218....3A ]
Duerbeck, H.W., 1981, Publ. Astron Soc. Pac. 93, 165 [BIBCODE 1981PASP...93..165D ]
Galkina, M.P. Shugarov, S.Yu., 1985, Perem. Zvezdy 22, 225 [BIBCODE 1985PZ.....22..225G ]
Ortolani, S., Rafanelli, P., Rosino, L., Vittone, A., 1980, Astron. Astrophys.
    87, 31 [BIBCODE 1980A&A....87...31O ]
Richter, G.A., 1981, Astrophys. Letters 21, 103 [BIBCODE 1981ApL....21..101R ]
Sharov, A.S., 1963, Astron. Zh. 40, 900 [BIBCODE 1963AZh....40..900S ]
Wenzel, W., Meinunger, I., 1978, Astron. Nachr. 299, 239 [BIBCODE 1978AN....299..239W ]