[vsnet-alert 928] CVC 140 (V844 her, V1028 Cyg, VW CrB, CVC online available, Editor Absence)

[Tonny Vanmunster <tvanmuns@innet.be>]

BELGIAN ASTRONOMICAL SOCIETY V.V.S. -  Working Group Variable Stars
Cataclysmic Variables Circular No.140                  1997, May 23
Ed.: T. Vanmunster, Walhostraat 1A, 3401 Landen, BELGIUM
     Internet: tvanmuns@innet.be                  TEL. 32-11-831504
     CVC Web Page : http://vsnet.astro.columbia.edu/~cba/cvc
===================================================================

V844 Her = Var43 Her [UGSU, 12.5p - 17.5p]
==========================================

Robert Modic, USA reports his visual detection of an outburst of
this poorly studied CVAP object. Confirmations have been received
from Timo Kinnunen, Finland and Tonny Vanmunster, CBA Belgium. 
Available observations :

1997 May 20.340 UT, <15.3  (Modic, 0.5-m refl.);
     May 21.319 UT,  13.1  (Modic);
     May 22.368 UT,  13.2  (Modic)
     May 22.93  UT,  13.5  (Kinnunen, 0.44-m refl.);
     May 23.138 UT,  13.1  (Modic)
     May 23.364 UT,  13.4  (Modic)
     May 23.892 UT,  13.6  (T. Vanmunster, 0.25-m SCT + unfilt. CCD);

V844 Her was last seen in outburst on October 7, 1996 by Ch. Scovil,
who detected it photograpically at mag. 12.2.

The object has been discovered by Antipin (IBVS 4360). It is located
at R.A. = 16h25m01s.7 and Decl. = +39d09'26" (J2000.0). Antipin
noted that the duration of the best observed outburst was between 12 
and 18 days.

Unfiltered time-series CCD photometry of V844 Her at the CBA Belgium
Observatory on October 13/14, 1996 showed the existence of weak 
superhumps with a mean amplitude of approx. 0.14 mag. This established
V844 Her as a new member of the UGSU-type dwarf novae. Unfortunately,
the extreme short observing window at that moment did not allow the 
determination of an accurate superhump period value. Perhaps the 
current outburst presents another opportunity ?


V1028 Cyg [UGSU, 13.0p - 18p]
=============================

Gene Hanson, Az has reported his visual detection of an outburst of
this very interesting SU UMa-type dwarf nova. No confirmative obser-
vations have been reported. Although V1028 Cyg now has returned to
quiescence, we strongly advise to follow-up this object, since
this might have been a normal outburst triggering a superoutburst
(see below for historical examples).

1997 May 17.440 UT,  14.2  (G. Hanson, 0.46-m refl.);
     May 17.451 UT,  14.1  (G. Hanson);
     May 17.469 UT,  14.1  (G. Hanson);
     May 18.427 UT,  14.6  (G. Hanson);
     May 18.466 UT,  14.7: (G. Hanson);
     May 19.409 UT, <15.1  (G. Hanson);
     May 19.465 UT, <15.6  (G. Hanson);
     May 19.994 UT, <14.5  (G. Poyner, 0.40-m refl.);


V1028 Cyg was last seen in outburst on August 7, 1996 by M. Bies-
mans and J. Pietz [CVC 102], when it reached mag. 13.5. This was
a short outburst and the object faded rapidly, but 4 nights later
it rebrightened again [CVC 103] and this became a superoutburst,
that lasted 11 days. Independent superhump observations were reported 
by Ouda Station and by CBA Belgium [CVC 105].
A full photometric summary of the August 1996 superoutburst is
given in CVC 107.

During the July 1995 superoutburst of V1028 Cyg [CVC 48], the
object became as bright as magnitude 12.7 [CVC 51, CVC 52], and the
Ouda team of Kyoto University, Japan, was the first to succeed in 
detecting superhumps. We refer to CVC 51 for a full account of the 
reported superhumps and their evolution over time.
Additionally, the star showed a post-outburst brightening [CVC 53],
a phenomenon which should be looked for during the present outburst
as well.


VW CrB = Var21 CrB [UGSU, 14.5 - <17.5p]
========================================

Following the announcements in CVC 137 and CVC 139, this object
has been monitored rather intensively by CCD photometry. The table
below lists available observations.

1997 May 07.890 UT, <17.2  (L. Jensen, 0.25-m SCT, unfilt. CCD);
     May 09.030 UT, <16.0  (G. Poyner, 0.40-m refl., visual);
     May 09.880 UT,  14.1  (T. Vanmunster, 0.25-m SCT, unfilt. CCD);
     May 11.037 UT,  14.4  (Poyner);
     May 11.976 UT,  14.5  (Poyner);
     May 12.908 UT,  14.6  (Poyner); 
     May 12.953 UT,  14.05 (Jensen);
     May 13.028 UT,  14.15 (Jensen);    
     May 13.885 UT,  14.32 (Jensen);
     May 13.936 UT,  14.6  (Poyner);
     May 13.96  UT,  14.5  (T. Kinnunen, visual);
     May 14.972 UT,  14.7  (Poyner)
     May 15.882 UT,  14.49 (Jensen);
     May 16.889 UT,  14.58 (Jensen);
     May 19.960 UT, <14.8  (Poyner)



CVC ONLINE AVAILABLE
====================

We are very pleased to announce that all CVC circulars (Nbr. 1 -
Nbr. 139) are now online accessible through the CBA Web site. 
We furthermore have included a primary index page, which presents 
a tabular overview of all circulars, allowing fast retrieval of 
information about a particular object.
Special thanks to Jonathan Kemp, Columbia University, New York
for his efforts in setting up the CVC Web site, which may be
accessed at following URL : 
  
      http://vsnet.astro.columbia.edu/~cba/cvc



EDITORIAL ABSENCE
-----------------

Please note that I will be absent between May 27 and May 29, 1997, 
due to participation in the 86th AAVSO Spring Meeting at Sion, 
Switzerland. 
I will furthermore be absent between June 7 and June 13, 1997,
this time for participating in the 190th Meeting of the American
Astronomical Society (AAS) at Winston-Salem, NC, USA.
At both occasions, I will present the Center for Backyard Astro-
phycis, its research on Cataclysmic Variables and specific
results of the DV UMa campaign.
I'd like to use this opportunity to thank the AAVSO, the CBA and 
Sky Publishing Corporation for their support.


Tonny Vanmunster

VSNET Home Page

Return to Daisaku Nogami

---

vsnet-adm@kusastro.kyoto-u.ac.jp