From: LARRY KLAES (ljk4_at_msn.com)
Date: Mon Sep 29 2003 - 11:34:18 PDT
----- Original Message -----
From: Makoto Uemura
Sent: Monday, September 29, 2003 2:20 PM
To: variable-star_at_SkyandTelescope.com
Cc: vsnet-adm_at_ooruri.kusastro.kyoto-u.ac.jp
Subject: AstroAlert: News from VSNET
==================================================================
This Is SKY & TELESCOPE's AstroAlert for Variable Stars
==================================================================
*** News from VSNET ***
The SU UMa-type nature of RU Hor and V551 Sgr has been established.
A new variable, which was discovered by V. Tabur, was first suspected
to be a nova, but may be a peculiar variable.
For more detail information about these objects,
see below, "VSNET Weekly Campaign Summary" of the last week.
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VSNET (Variable Star Network) is an international variable star observing
network, covering various areas of novae, supernovae, cataclysmic variables
(CVs), X-ray transients, and other classical eruptive, pulsating, and
eclipsing variables. VSNET is one of invited contributing organizations
to the SkyPub AstroAlert system.
The "News from VSNET", mainly focusing on recent remarkable activities of
CVs and related systems, is issued on a weekly basis, except on occasions
of extremely urgent or transient events.
Please refer to the VSNET Home Page for more details of events and
objects listed.
VSNET Home Page: http://www.kusastro.kyoto-u.ac.jp/vsnet/
VSNET provides a number of mailing lists, on which various news and topics
are discussed. Subscriptions to the VSNET mailing lists are free of charge;
please refer to the instruction on the above page if a reader needs more
information of the list structure.
CCD observations of such targets are a relatively easy task for a 20-40cm
telescope; simply take as many CCD frames (with exposure times 10-30 sec)
as possible, spanning several hours per night. The only requirements are
the weather and your patience! If you need more help on the observing
technique, please feel free to ask on the vsnet-campaign list.
We would sincerely appreciate volunteers who would join the VSNET
Collaboration team to study the wonders of these exotic variable stars.
To join the VSNET campaign collaborative list, send an e-mail to
vsnet-adm_at_kusastro.kyoto-u.ac.jp (VSNET administrator)
with a line "SUBSCRIBE vsnet-campaign."
(VSNET campaign members are strongly recommended to subscribe to vsnet-alert
at the same time).
Regards,
Taichi Kato
On behalf of the VSNET administrator team
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The following was issued on September 29, 2003, as VSNET campaign
circulation 1413
[Note a large part of detailed information is posted to vsnet-campaign
sub-lists].
VSNET Weekly Campaign Summary
*** Last week news ***
(new targets)
RU Hor (RA = 02h46m05s.38, Dec = -63d35'04".0)
R. Stubbings reported that the dwarf nova RU Hor is undergoing an
outburst (13.2mag on Sep. 27) (vsnet-outburst 5941). The object
only infrequently undergoes outburst (2000 November, short outburst;
1999 August, long outburst?) (vsnet-campaign-dn 3980). The outburst
was also recorded by the ASAS-3 observation (vsnet-campaign-dn 3983).
The light curve observed by G. Bolt on Sep. 27 clearly showed fully
developed superhumps with an amplitude of 0.25 mag. RU Hor is now
established to be a genuine SU UMa-type dwarf nova. A preliminary
superhump period is 0.0716(3) d (vsnet-campaign-dn 3984).
SN 2003if (RA = 03h19m52s.61, Dec = -26d03'50".5)
SN 2003if is hosted by NGC 1302, a face-on early spiral galaxy.
The CfA team has revealed that it was type Ia SN about 3 weeks after
maximum based on Sept. 22.46 UT spectrum. The discovery magnitude
is 17.6-17.7mag on Sep. 20 and 21, respectively. Considering that
the expected maximum for typical unreddened SN Ia is mag about 13.5,
and that the spectrum shows no remarkable extinction, it must be
quite peculiar SN Ia (vsnet-campaign-sn 697). W. Li reported the
object must be quite subluminous at peak, i.e., a 91bg-like object
(vsnet-campaign-sn 698).
OR And (RA = 23h04m37s.4, Dec = +49d27'24")
The light curve of this poorly studied VY Scl-type star observed
by T. Krajci suggested the presence of 3-hour modulations with a
profile resembling that of superhumps in permanent superhumpers. The
light curve also exhibited relatively strong QPO-like variations.
The overall light curve resembles that of short-period novalike
stars such as V592 Cas (vsnet-campaign-nl 138).
SN 2003ig (RA = 04h09m43s.50, Dec = +37d00'45".8)
SN 2003ig is hosted by UGC 2971, a spiral galaxy near the galactic
plane. The expected maximum for typical SN Ia is mag about 17.1
(vsnet-campaign-sn 699).
SN 2003ih (RA = 03h43m57s.72, Dec = +39d17'43".2)
SN 2003ih is hosted by UGC 2836, an apparently lenticular galaxy
near the galactic plane. The expected maximum for typical SN Ia
is mag about 16.6. The morphology of the host galaxy suggests that
it would be of type Ia. UGC 2836 produced SN IIn 2001I (brightest
reported mag 17.6), which suggest that this galaxy experienced the
recent star formation (vsnet-campaign-sn 699).
SN 2003ii (RA = 02h33m04s.80, Dec = +35d30'29".7)
SN 2003ii is hosted by MCG +06-6-53, a spiral galaxy
(vsnet-campaign-sn 699). The CfA group took a spectrum of SN 2003ii
on Sept. 26.37 UT, which revealed that it is a normal type II SN.
The recession velocity of the host galaxy was measured as 13400 km/s
(vsnet-campaign-sn 700).
BF Cyg (RA = 19h23m53s.5, Dec = +29d40'29")
The object is now fading (vsnet-campaign-symbio 81).
VY Scl (RA = 23h29m00s.4, Dec = -29d46'45")
The ASAS-3 observations suggest that the VY Scl-type prototype has
entered a deep fading. A look at the image suggests that the object
has faded much fainter than V=14.5. The initial indication of this
fading was reported in June by S. Kerr. Following a gradual fading,
the fading rate seems to have recently increased. The object may
reach mag 18 as inferred from the past deepest minimum
(vsnet-campaign-nl 140, 141).
SN 2003ij (RA = 05h55m41s.18, Dec = +85d54'21".7)
SN 2003ij is hosted by UGC 3336, a barred-spiral galaxy. The
expected maximum for typical SN Ia is mag about 16.3
(vsnet-campaign-sn 700).
GSC 396.1222 (RA = 16h46m01s.6, Dec = +07d18'50")
P. Wils reported that, in the night of Monday 29 on Tuesday 30
September, the long period eclipsing binary GSC 396-1222 is having
another deep eclipse. For more information, see
http://wiki.tass-survey.org/tass/view.do?nodeId=Tass&contentId=TassJ164601.6%2b071850
(vsnet-campaign-ecl 91).
(continuous targets)
V5113 Sgr (RA = 18h10m10s.42, Dec = -27d45'35".2)
(= Nova Sgr 2003 No.2)
The H_alpha line has become appreiably stronger in the spectrum
taken by M. Fujii on Sep. 21, compared to the Buil's spectrum taken
only 0.6 day earlier (vsnet-campaign-nova 1485). The Fe II series
lines also became stronger. C. Buil reported a similar change of
this star was confirmed in the spectrum taken on Sep. 25
(vsnet-campaign-nova 1496). The nova may recently be oscillating
(vsnet-campaign-nova 1491, 1479, 1480).
V551 Sgr (RA = 18h00m56s.46, Dec = -34d35'45".6)
In the light curve observed by R. Santallo on September 23,
prominent superhumps were detected, which finally confirmed the
supposed SU UMa-type nature of V551 Sgr (vsnet-campaign-dn 3965).
Superhumps were already present in the light curve on Sep. 22 by
B. Monard (vsnet-campaign-dn 3970, 3967). The best superhump period
is 0.06748 d (vsnet-campaign-dn 3966, 3974, 3976, 3985). A striking
period change of superhumps was reported (vsnet-campaign-dn 3979).
The observation by P. Nelson indicate that V551 Sgr experienced a
short precursor stage on Sep. 21 (vsnet-campaign-dn 3982). The
superoutburst is now ongoing (vsnet-campaign-dn 3972, 3987).
SU Tau (RA = 05h49m03s.7, Dec = +19d04'21")
The object is still faint (vsnet-campaign-rcb 162).
New/brighter object near HX PEG?
(RA = 23h40m03s, Dec = +12d36'45")
The object turned out to be an RR Lyr star (vsnet-campaign-unknown
251, 252, 253, 254, 255).
MV Lyr (RA = 19h07m15s.93, Dec = +44d01'10".7)
The bright state continues (vsnet-campaign-nl 139).
Nova Cru 2003 (RA = 12h23m16s.2, Dec = -60d22'34")
The object rapidly faded in early September (vsnet-campaign-nova 1492).
V1329 Cyg (RA = 20h51m01s.3, Dec = +35d34'53")
The outburst is ongoing. It is around 12.6-12.8mag
(vsnet-campaign-symbio 80).
SN 2003ie (RA = 12h03m18s.15, Dec = +44d31'34".6)
The Asiago group showed that it is type II SN (vsnet-campaign-sn 699).
V585 Lyr (RA = 19h13m58s.5, Dec = +40d44'09")
R. Novak reported clear superhumps on September 22
(vsnet-campaign-dn 557). The data on September 23 showed a marked
decrease of the superhump amplitude. Combined data sets now clearly
demonstrate that the superhump period was the dominant period even
during the earliest stage. The growth of the genuine superhumps was
rather slow, but not particularly unusual for this short superhump
period (vsnet-campaign-dn 3971). T. Kato reported that the timing
analysis of the superhump maxima has yielded a definite positive
dot(P)/P = +9x10^(-5). The times of superhumps have been well
expressed by a single positive period derivative (vsnet-campaign-dn
3975). The object experienced the stage of expected regrowth of
superhumps in a late plateau phase (vsnet-campaign-dn 3981, 3986).
The superoutburst will soon enter a rapid fading phase
(vsnet-campaign-dn 3968, 3973).
ES Aql (RA = 19h32m21s.58, Dec = -00d11'31".2)
M. Simonsen reported that the object is recently brightening
(vsnet-campaign-rcb 159, 161).
delta Sco (RA = 16h00m19s.9, Dec =