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\input ibvs2.sty

\begin{document}

\IBVShead{5544}{8 July 2004}

\IBVStitle{The Cataclysmic Variable V358 Lyrae: Removing Ambiguities}

\IBVSauth{Antipin, S. V.$^{1, 2}$; Samus, N. N.$^{2, 1}$; Kroll, P.$^3$}

\IBVSinst{Sternberg Astronomical Institute, 13, University Ave.,
Moscow 119992, Russia;\\ e-mail: antipin@sai.msu.ru, samus@sai.msu.ru} 
\IBVSinst{Institute of Astronomy, Russian
Academy of Sciences, 48, Pyatnitskaya Str., Moscow 119017, Russia}
\IBVSinst{Sonneberg Observatory, Sonneberg, Germany;\\ e-mail: pk@4pisysteme.de}

\SIMBADobj{V358 Lyr}

\IBVSkey{cataclysmic variables}

\IBVSabs{We show that the magnitude in maximum suggested for V358 Lyr, allegedly a possible Nova,}
\IBVSabs{refers to a plate defect, and present accurate coordinates, finding charts,}
\IBVSabs{and a list of reliable observations for this enigmatic cataclysmic variable.}


\begintext

The variable star V358 Lyr = S~9649 was discovered by Hoffmeister
(1967). The discoverer gave the photographic range from 16\mm\ to
fainter than 18\mm\ and considered the star a possible long-period
variable. Galkina and Shugarov (1985) found no trace of the star
on Moscow plates covering the time interval JD~2434112--2445264.
Richter (1986) suggested a cataclysmic-star classification for
V358~Lyr. He presented the observations of the variable given in
Table~1 (in our presentation of this table, we restore the
fractions of the Julian Days dropped by Richter, for clarity of
the further discussion). Te$_4$ are sky patrol plates, GC are
plates taken with the 40~cm astrograph ($F=160$~cm).

\begin{center}
{\normalsize Table 1. Observations of V358~Lyr from Richter (1986)} \vskip2mm
\begin{tabular}{llrr}
\hline
Plate & 1965 & JD & $m_{\rm pg}$\\
\hline
Te$_4$ 4601&    Jun 25 &  2438937.483 &  [14.5\\
Te$_4$ 4609&    Jun 29 &     8941.483 &   13.27\\
GC 1387  &   Aug  4  &    8977.480  &  16.42\\
GC 1388  &   Aug 19  &    8992.399  &  17.31\\
GC 1389  &   Aug 23  &     8996.412 & [18.5\\
\hline
\end{tabular}
\end{center}

Richter (1986) did not find any trace of the star to 21\mm\ on
Palomar prints, concluded that ``the question whether V358 Lyr is
a classical nova or a WZ~Sagittae type object remains open'', but
argued for the latter possibility. There is nothing red near the
position of V358~Lyr, and thus its being a member of the
cataclysmic-variable class is quite plausible.

We found all the plates studied by Richter in the plate stacks of
Sonneberg Observatory. Moreover, the plate collection contains
several additional plates relevant to the problem, taken with the
other Sonneberg 40~cm astrograph, GB ($F=200$~cm). We generally
confirm the results of Table~1. Figure~1 reproduces the field of
the star from Hoffmeister's discovery plate, GC~1387, with the
variable marked by Hoffmeister. Its coordinates, measured by us
with respect of reference stars from the 2MASS catalog, are:
$$18\hr59\mm32\fsec95 \ \ \ +42\deg24\arcm12\farcs2\ \ {\rm J2000.0,\ \
ep.\ 1965.591}.$$ These coordinates are accurate to
$\sim0\farcs5$. However, the object's position in Te$_4$~4609,
measured with respect of Tyc2 and GSC stars and accurate to $\sim 2\arcs$,
$$18\hr59\mm33\fsec5 \ \ \ +42\deg24\arcm21\arcs\ \ {\rm J2000.0},$$
differs by $14\arcs$, outside estimated errors. Moreover, the region
of V358~Lyr in Te$_4$~4609, shown in Fig.~2, contains at least
two more star-like objects missing on DSS images. The plate
GB~1911 (JD~2438941.506), with a much better plate limit than for
Te$_4$~4609, whose exposure time partially overlaps the exposure
of Te$_4$~4609, shows nothing in the position of V358~Lyr. In our
opinion, the image in Te$_4$~4609 is a plate defect rather than
the variable.

\IBVSfig{8cm}{5544-f1.eps}{The $10\arcm\times10\arcm$ field around V358
Lyr on the discovery plate, GC~1387. North is on top, east is to
the left. The thick bar below V358~Lyr is the ink mark left by
C.~Hoffmeister.}

\IBVSfigKey{5544-f1.eps}{V358 Lyr}{finding chart}


\IBVSfig{8cm}{5544-f2.eps}{The $20\arcm\times20\arcm$ field around
V358~Lyr on the patrol plate Te$_4$~4609. The three probable
plate defects are marked with numbers 1, 2, 3. No.~1 was
identified with V358~Lyr by G.~Richter.}

\IBVSfigKey{5544-f2.eps}{V358 Lyr}{finding chart}


We are left with the observations presented in Table~2, replacing
the table from Richter (1986).

\begin{center}
{\normalsize Table 1. The corrected list of Sonneberg
observations for V358~Lyr} \vskip2mm
\begin{tabular}{llrr}
\hline
Plate & 1965 & JD & $m_{\rm pg}$\\
\hline
Te$_4$ 4601&    Jun 25 &  2438937.483 &  [14.5\\
GB 1905  &   Jun 25  &    8937.503  &  [17\\
GB 1908  &   Jun 28  &    8940.505  &  [17\\
GB 1911  &   Jun 29  &    8941.506  &  [17\\
GC 1387  &   Aug  4  &    8977.480  &  16.42\\
GC 1388  &   Aug 19  &    8992.399  &  17.31\\
GC 1389  &   Aug 23  &     8996.412 & [18.5\\
\hline
\end{tabular}
\end{center}

The Moscow plate collection now contains 89 additional plates, not
studied by Galkina and Shugarov (1985), covering
JD~2445525--2450366. Nothing brighter than 17\mm\ can be seen in
the position of V358~Lyr.

We conclude that V358~Lyr is most probably a faint cataclysmic
variable with extremely rare outbursts. Richter (1986) argued
that the magnitude 13\fmm3 in maximum made the star, were it a
Nova, unbelievably far from the galactic plane. It is even more
so with the corrected magnitude in maximum, 16\fmm4. It should be
remembered, however, that we know nothing about the star's
behavior in July, 1965.

\bigskip

One of us (S.V. Antipin) wishes to thank Sonneberg Observatory
for excellent hospitality during his work in the Observatory's
plate archive in 2003. Thanks are due to the staff of Sonneberg
Observatory for assistance in scanning plates. Sonneberg
Observatory is operated by 4$\pi$ Systeme company. The work of the
GCVS team (S.V.~Antipin, N.N.~Samus) is supported, in part, by
grants from the Russian Foundation for Basic Research (grant
02-02-16069), The Federal Scientific and Technological Program
``Astronomy'', the program ``Non-Stationary Processes in
Astronomy'' of the Presidium of Russian Academy of Sciences, and
the program of support for leading scientific schools of Russia
(grant NSh-389-2003-2).


\references

Galkina, M.P., Shugarov, S.Yu., 1985, {\it Perem. Zvyozdy}, {\bf
22}, 225

Hoffmeister, C., 1967, {\it Astronomische Nachrichten}, {\bf 289}, 205

Richter, G., 1986, {\it IBVS}, No. 2971

\endreferences
\end{document}
