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[vsnet-alert 2435] Re: V844 Her outburst
- Date: Thu, 10 Dec 1998 22:38:04 +0900 (JST)
- To: vsnet-alert
- From: Taichi Kato <tkato>
- Subject: [vsnet-alert 2435] Re: V844 Her outburst
- Sender: owner-vsnet-alert@kusastro.kyoto-u.ac.jp
Re: V844 Her outburst
Extracted from previous messages. Object of extreme importance.
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Date: Mon, 30 Sep 1996 17:12:58 +0900
From: Taichi Kato <tkato@kusastro.kyoto-u.ac.jp>
Subject: [vsnet 834] new UG star in Her
Dear dwarf nova fans,
According to IBVS No. 4360, Antipin discovered another new dwarf nova
(bright!) in the eta Her field.
Var43
16h 25m 01s.7 +39o 09' 26" (J2000.0)
UG 12.5-17.5p
Antipin reports that the duration of the best-observed outburst is
between 12 and 18 days.
Regards,
Taichi Kato
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From: c.scovil@genie.com
Date: Sat, 12 Oct 96 07:52:00 GMT
Subject: [vsnet-obs 4061] Observations - outburst V43 He
Following Dr. Kato's notice of Antipin's V43 in Hercules I took a photo of the
field on Oct. 7th at 1:34 UT. The variable was bright, at about 12.2 using
Antipin's sequence, which I assume to be Photoelectric (V).
Visual observation of the star Oct. 12 at 0.0 UT showed it at magnitude 14.3.
Regards,
C. Scovil, AAVSO
============================================================================
From: VANMUNSTER Tonny <tvm@lms.be>
To: vsnet-obs@kusastro.kyoto-u.ac.jp (vsnet-obs)
Date: Mon, 14 Oct 96 13:44:05 METDST
Subject: [vsnet-obs 4075] Var43 Her : new UGSU-type dwarf nova
Dear Colleagues,
Unfiltered time-series CCD photometry of Var43 Her (*) at the
Center for Backyard Astrophysics Belgium (CBA Observatory),
using a 25-cm f/6.3 SCT telescope and ST-7 CCD, on October 13/14,
1996 shows the existence of weak superhumps with a mean amplitude
of approx. 0.14 mag. This establishes Var43 Her as a new member of
the UGSU-type dwarf novae.
Determination of a superhump period value is extremely difficult due
to the short observing window (photometry of Var43 Her in Belgium
currently is restricted to approx. 1.5 hours). We therefore would
like to request assistance from other observatories, so that
multi-longitudinal coverage becomes possible.
The present outburst of Var43 Her was first announced by Ch. Scovil
(VSNET message), and detected on Oct. 7, 1996. The object is now
fading and any attempts to study the superhumps should be made in
the next couple of nights.
Kind regards,
Tonny Vanmunster
CBA Belgium
(*) Var43 Her was discovered by Antipin (IBVS 4360) and is located
at R.A. = 16h25m01s.7, Decl = +39d09'26" (J2000.0). Magnitude
range is 12.5 - 17.5p.
============================================================================
Date: Sat, 24 May 1997 07:35:55 +0900 (JST)
From: Taichi Kato <tkato@kusastro.kyoto-u.ac.jp>
Subject: [vsnet-alert 927] superoutburst of V844 Her = Var43 Her
The recently discovered SU UMa-type dwarf nova, V844 Her = Var43 Her
is undergoing a superoutburst as indicatied by the following observations.
(Most magnitudes based on Antipin's photographic sequence; the true
V-magnitude may be brighter by ~0.5 to 1.0 mag.)
YYMMDD(UT) mag code
970519.964 <149 POY
970520.340 <153 MRV
970521.319 131 MRV
970522.367 132 MRV
970522.930 135 KNN
970523.137 131 MRV
970523.364 134 MRV
The object was last reported to be in outburst in 1996 Oct., when
Tonny Vanmunster detected superhumps, finally enabling an unambiguous
classification of this object (cf. vsnet-obs 4075,
http://vsnet.kusastro.kyoto-u.ac.jp/vsnet/Mail/vsnet-obs/msg04075.html).
Regards,
Taichi Kato
============================================================================
Date: Sat, 24 May 1997 19:21:16 +0200 (MET DST)
From: Tonny Vanmunster <tvanmuns@innet.be>
Subject: [vsnet-obs 5837] V844 Her in superoutburst. A story of bad luck.
Dear colleagues,
Last night I obtained over 4 hours of CCD photometry of Var43 Her =
V844 Her. The resulting light curve clearly showed prominent super-
humps, hence qualifying the present outburst again as a superoutburst.
So far the good news ...
But ... at the moment I launched the period determination programme, my
hard disk crashed (hopefully without data loss). When I have my computer
back in a few days, I hope to continue the period determination (without
interrupts this time ?) and I will communicate the superhump period value.
Regards,
Tonny Vanmunster
CBA Belgium
============================================================================
Date: Tue, 27 May 1997 10:28:49 +0900 (JST)
From: Taichi Kato <tkato>
Subject: [vsnet-alert 940] V844 Her: unique short orbital period SU UMa star
V844 Her: unique short orbital period SU UMa star
Recent reports [1,2] on V844 Her (=Var43 Her) confirm the star as
being an SU UMa star having one of the shortest superhump periods.
A table of short Psh SU UMa stars (taken from [3]; stars with (*)
are newly added here):
Psh Porb
---------------------------------------------------------
V485 Cen 0.0421 0.041 (*)
DI UMa 0.0555
V844 Her 0.056 +/- 0.001 (*)
LL And 0.05700
WZ Sge 0.05714 0.05669
AL Com 0.0572 0.05666
SW UMa 0.0583 0.05681
HV Vir 0.05865 0.05799
WX Cet 0.05936 0.0582
RZ LMi 0.05946
T Leo 0.0602 0.05882
EG Cnc 0.06036 0.05821
Aside from V485 Cen, all of these short Psh SU UMa stars are either
what is called WZ Sge-type dwarf novae and ER UMa-type (or RZ LMi-type)
dwarf novae. The former category contains WZ Sge, AL Com, HV Vir, EG Cnc,
and related members LL And, SW UMa, WX Cet and T Leo. The latter group
contains DI UMa and RZ LMi. Which group will V844 Her belong to, or
comprise by itself a unique class?
From available photometric materials ([4] and reports to VSNET),
bright (super) outbursts are separated by 220-230 days, without detectable
normal outbursts (despite the brightness of the object) so far. Will it
mean V844 Her is a WZ Sge-type dwarf nova with a supercycle length of
220-230 (!) days?
Regards,
Taichi Kato
(please continue the discussion in vsnet-chat if necessary)
References:
[1] T. Vanmunster, CVC 141, or http://vsnet.kusastro.kyoto-u.ac.jp/vsnet/Mail/vsnet-alert/msg00935.html
[2] L. T. Jensen [vsnet-obs 5854] http://vsnet.kusastro.kyoto-u.ac.jp/vsnet/Mail/vsnet-obs/msg05854.html
[3] D. Nogami, S. Masuda, T. Kato 1997, PASP submitted
[4] S. V. Antipin 1996, IBVS 4360
============================================================================
Date: Sun, 1 Jun 1997 05:18:06 -0400 (EDT)
From: Joe Patterson <jop@astro.columbia.edu>
Subject: [vsnet-alert 953] V844 Her = Var43 Her
V844 Herculis (= Var43 Her) continues to show strong superhumps
during its current superoutburst. Merged coverage from 5 CBA stations
shows a principal period of 0.05602+-0.00011 d during May 25-31. Very
short. Very complex too: large wiggles in the O-C and variability in
the waveform suggest the possibility of another signal closely spaced
in period. Fourier analysis yields a second period at 0.05534+-0.00010
d, but this must be regarded with caution as power-spectrum structure
can also be produced by mere amplitude changes (if strong enough).
Second period or no, the star is of very high interest, and we
earnestly seek help from other observers able to obtain time-series
photometry, in order to produce the best sampling of this remarkable
light curve. We expect to be watching the star throughout June.
The CBA team, so far:
Joe Patterson (New York) (jop@astro.columbia.edu, 802-425-5008)
Tonny Vanmunster (Belgium)
Lasse Jensen (Denmark)
Dave Skillman (Maryland)
Dave Harvey (Arizona-Tucson)
Bob Fried (Arizona-Flagstaff)
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