[vsnet-campaign 788] CP Dra rare outburst: observations requested!

[Taichi Kato <tkato>]

CP Dra rare outburst: observations requested!

   As reported in vsnet-outburst 1691 by Christopher Jones, the poorly
known dwarf nova CP Dra is undergoing a rare, bright outburst.

   2001 02 23.9340  14.5  C. Jones
        02 24.144   14.3  M. Reszelski, confirmation

   The last outburst of CP Dra was observed on 2000 May 15 by Tonny
Vanmunster (vsnet-alert 4851).  That outburst was mag 15.3 and relatively
rapidly faded.  The brightness of the present outburst surpasses that
of the GCVS maximum (15.1) and other avilable records.  The present outburst
may thus be a superoutburst.  The outburst is naturally a top-priority
target of the VSNET Collaboration team (as well as the southern TV Crv)!

   The object has been reported as a "supernova" twice:

   see also vsnet-chat 2949:

    According to the literature (Perem. Zvezdy) listed in GCVS, six
outbursts were detected on ~400 plate collections.  This number was
about half that of CI UMa, which was investigated by the same author.

    The object is listed twice as a possible SN.

101540.0 +732606 (2000.0) SN1904 * N3147 - - - - - D.Isaac-Roberts
101540.0 +732606 (2000.0) SN1972 * N3147 - - - - - R.Altizer

   vsnet-chat 2954:

  According to GCVS (NL59=IBVS 834), CP Dra appears to be recorded by
R. Altizer on IAUC 2381 (probably issued on early 1972) as "supernova
or nova near NGC 3147".  This star has also been noted as "n" in D.
Roberts (1914), AN, 197, 57.  It seems to be 1904 event, but not
certain (I cannot read them because they are not electrically
accessable).  This "supernova or nova near NGC 3147" is also described
in IAUC 2383 (also not-accessable), which can be the identification of
the nature of the recurrence.

  Very timely, SN 1972H has occured in this galaxy.  It was discovered
by Goranskij (IAUC 2431, issued on 1972 Aug.), and follow-uped by
several observers.  The atlas of this SN can be seen on Barbon (1973)
A&Ap, 29, 43.  Also, SN 1997bq has occured in this galaxy.

  These two SNe are in the disk (spiral) region of NGC 3147 (offset is
1' or so), while CP Dra is far away: about 5'.7 WNW of the center of
this galaxy (if the GCVS position is correct).  Bruch et al. (1987),
A&ApS 70, 481 tells that Hoffmeister (1966), AN, 289, 139 or
Kolotovkina (1979) Perem. Zvezdy 3, 665 has the other atlas: can you
check them, Taichi?

Sincerely Yours,
Hitoshi Yamaoka, Kyushu Univ., Japan
yamaoka@rc.kyushu-u.ac.jp

  vsnet-chat 2955:

   Yes, I have checked the both (the latter reference should be its
"Supplement").  The outburst statistics mentioned in the previous message
was from the latter reference.  The former reference has been checked
during my previous study of precise coordinates of variable stars.

   However, I remember I have seen (but don't remember the bibliographic
data) an (old) AN? reference that showed a chart with the galaxy.  Although
the maximum in GCVS apparently took over Kolotovkina's value, the maximum
recorded in the AN? reference was much brighter (around 13?).

>   Very timely, SN 1972H has occured in this galaxy.  It was discovered
> by Goranskij (IAUC 2431, issued on 1972 Aug.), and follow-uped by
> several observers.  The atlas of this SN can be seen on Barbon (1973)
> A&Ap, 29, 43.  Also, SN 1997bq has occured in this galaxy.

   Perhaps this suggests that frequent visitors to CP Dra may have a better
chance to discover a SN than to watch other field dwarf novae ;-).

Regards,
Taichi Kato

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