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[vsnet-obs 1827] CVC 76 (V701 Tau, IP Peg, FS Aur)
- Date: Sun, 31 Dec 1995 16:17:30 -0100
- To: observations@aavso.org, j.bortle@genie.geis.com, guy@tahq.demon.co.uk, tkato@kusastro.kyoto-u.ac.jp, gp@star.sr.bham.ac.uk, lasse.teist@thranethrane.dk400.dk, pvancaut@innet.be, bill.worraker@aea.orgn.uk, nogami@kusastro.kyoto-u.ac.jp, safnet@mesiob.obspm.fr, KFA02524@niftyserve.or.jp, sno@iris.elte.hu, vsnet-obs@kusastro.kyoto-u.ac.jp, NAH01147@niftyserve.or.jp, ebroens@innet.be, fidusz@alba.zpok.hu
- From: Tonny Vanmunster <tvanmuns@innet.be>
- Subject: [vsnet-obs 1827] CVC 76 (V701 Tau, IP Peg, FS Aur)
- Sender: owner-vsnet-obs@kusastro.kyoto-u.ac.jp
BELGIAN ASTRONOMICAL SOCIETY V.V.S. - Working Group Variable Stars
Cataclysmic Variables Circular No.76 1995, December 31
Ed.: T. Vanmunster, Walhostraat 1A, 3401 Landen, BELGIUM
Internet: tvanmuns@innet.be TEL. 32-11-831504
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The CATACLYSMIC VARIABLES Home Page: hht://www.cv.psi.edu
===================================================================
V701 Tau [UGSU, 15.0p - <21p]
=============================
Following the outburst announcement in our previous circular, this
object has been intensively monitored by Taichi Kato and the Ouda
Team at Kyoto University, Japan, as well as by a number of amateurs.
We have collected all available observations in the photometric
summary below. It constitutes the first systematic observing run,
since the discovery of V701 Tau, now 25 years ago.
The most important event in the present monitoring action has been, beyond
any doubt, the detection of superhumps, which is reported in the
compilation of VSNET communications that we received from T. Kato
(chronological order) :
>> Message dd. December 26, 1995
Kato remarks that the observations reported in CVC 75 probably are the
first ever visual observations of V701 Tau since its discovery in 1970.
He further adds : "The Ouda team has just confirmed this outburst using a
60-cm telescope + CCD, giving a rough magnitude estimate of V~14.3.
Observers should note that the object is slightly mis-identified on the
atlas by Downes & Shara (1993). The true object is located ~30 arcsec ESE
of the position given in their catalog. This identification has been con-
firmed by checking the discovery report by Esastova, L.K. 1973, Astron.
Tsirk. 774."
The 1970 outburst, reported by Esastova, lasted for at least 10 days and
revealed a maximum magnitude of 15.0 mpg.
>> Message dd. December 26, 1995
M. Iida (Nagano, Japan) communicates the following precise position of
V701 Tau determined from a CCD image, using the position of 6 GSC stars
(mean residual 0".6) : R.A. = 03h44m01s.97, Decl. = 21d57'09".6 (J2000.0)
>> Message dd. December 27, 1995
Kato reports astrometric observations of V701 Tau, based on a preliminary
anysis of CCD frames taken at Ouda Station. The derived position, based on
4 GSC stars, is : R.A. = 03h44m01s.91, Decl. = +21d57'07".2 (J2000.0).
Kato also communicates that time-resolved photometry showed a gradual decline
of 0.10 mag in four hours, and that a first hint of low amplitude modulations
became evident.
>> Message dd. December 28, 1995
Kato eventually reports the detection of superhumps : "V-band time-resolved
CCD observations of V701 Tau (Dec. 27.446 -- 27.706 UT) finally revealed a
development of superhumps in V701 Tau. Superhumps are still small in ampli-
tude (~0.05-0.06 mag), but are clearly present and are likely to be just
growing. A preliminary analysis gives the best period of 0.073 day. The
present observations thus firmly establish the SU UMa-type nature of this
dwarf nova."
>> Message dd. December 30, 1995
Two days later, the reported superhumps are fully grown, according to Kato :
"CCD photometry of V701 Tau at Ouda Station on Dec. 29 clearly shows fully
grown superhumps with an amplitude of 0.25 in V. A preliminary analysis
yields a superhump period of P=0.069 day, which is significantly shorter
than one obtained in early stages of the superhump development."
-----------------------------------------------------------------------
DATE (UT) MAGN MS SEQ OBSERVER REMARKS SOURCE
-----------------------------------------------------------------------
1995 12 24.951 [15.6: mv GSC Vanmunster, T. CVC 75
1995 12 25.847 14.5 mv GSC Vanmunster, T. CVC 75
1995 12 25.866 14.5 mv GSC Poyner, G. CVC 75
1995 12 25.951 14.4 mv GSC Vanmunster, T. CVC 75
1995 12 25.983 14.1 mv GSC Broens, E. CVC 75
1995 12 26.548 14.4 CV Kato & Ouda Team VSNET
1995 12 26.951 14.4:: mv GSC Poyner, G. VSNET
1995 12 27.023 14.5: mv GSC Broens, E. VSNET
1995 12 27.577 14.5 CV Kato & Ouda Team VSNET
1995 12 27.903 [14.3 mv GSC Broens, E. VSNET
1995 12 27.957 14.4 mv GSC Pietz, J. VSNET
1995 12 28.934 [14.3 mv GSC Broens, E. VSNET
1995 12 28.940 14.6 mv GSC Pietz, J. VSNET
1995 12 28.985 14.7 mv GSC Vanmunster, T. VSNET
1995 12 29.567 14.5 CV Kato & Ouda Team VSNET
1995 12 29.772 [14.3 mv GSC Poyner, G. VSNET
IP Peg [UG, 12.0B - 16.6B]
==========================
CVC 74 announced an outburst of IP Peg. We subsequently received a
substantial amount of observations, including several eclipse timings,
making it virtually impossible to compile a photometric summary. However,
as soon as first results and conclusions related to observational data of
the current outburst become available as part of the IP Peg project (headed
by B.Worraker, Didcot, UK - TA/BAAVSS), we will report on them in the
Cataclysmic Variables Home Page.
FS Aur [UGZ:, 14.4v - 16.2v]
============================
The outburst of FS Aur, mentioned in CVC 74, has resulted in the following
photometric summary :
-----------------------------------------------------------------------
DATE (UT) MAGN MS SEQ OBSERVER REMARKS SOURCE
-----------------------------------------------------------------------
1995 12 10.465 15.9 CU Iida, M. CVC 74
1995 12 10.469 15.4 CU Iida, M. CVC 74
1995 12 10.805 [14.7 mv Poyner, G. CVC 74
1995 12 14.487 15.8 CU Iida, M. CVC 74
1995 12 15.917 14.8 mv VSO Broens, E. CVC 74
1995 12 16.090 14.4 mv VSO Vanmunster, T. CVC 74
1995 12 16.863 14.6 mv Pietz, J. VSNET
1995 12 16.867 14.5 mv VSO Broens, E. VSNET
1995 12 20.426 [14.9 mv Jensen, L. VSNET
1995 12 21.899 15.1 mv Pietz, J. VSNET
1995 12 25.946 16.1 mv Poyner, G. VSNET
1995 12 26.016 [14.8 mv VSO Broens, E. VSNET
1995 12 27.876 15.3: mv Pietz, J. VSNET
Tonny Vanmunster
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