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[vsnet-campaign-news 185] News from VSNET
*** News from VSNET ***
An unusual phase reversal of superhumps, which was originally
discovered in ER UMa, was also detected in V1159 Ori.
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://vsnet.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@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 December 2, 2002, as VSNET campaign
circulation 1351
[Note a large part of detailed information is posted to vsnet-campaign
sub-lists].
VSNET Weekly Campaign Summary
*** Last week news ***
(new targets)
HV Aur (RA = 04h53m16s.8, Dec = +38d16'29")
K. Torii reported the detection of a bright outburst of the poorly
known dwarf nova, HV Aur (14.75 mag on Nov. 27 and 14.71 mag on
tonight) (vsnet-campaign-dn 3056). On November 27 and 28,
superhumps (about 0.25 mag) were clearly visible (vsnet-campaign-dn
3057). The Nyrola team reported V=14.8 on November 28
(vsnet-campaign-dn 3058, 3060). On November 29, the amplitude of
superhumps was 0.2 mag, and has slightly different profile than on
the previous nights (vsnet-campaign-dn 3063). T. Kato analyzed
the light curves and reported a preliminary period of 0.08559 d,
which closely agrees with Nogami et al. (1995) IBVS 4163
(vsnet-campaign-dn 3059, 3061).
DX And (RA = 23h29m46s.72, Dec = +43d45'04".2)
P. Schmeer reported a rare outburst of DX And (13.0mag) on
November 27. The previous outburst of this SS Cyg-type dwarf nova
occurred from 2001 Aug. 21 to Sept. 07 (vsnet-campaign-dn 3053, 3055).
In the light curve taken by K. Tanabe, there was 0.05 mag flare-like
brightening lasting for 15 min, as well as other minor variations
(vsnet-campaign-dn 3062).
V1159 Ori (RA = 05h28m59s.52, Dec = -03d33'52".8)
As reported by R. Stubbings and A. Pearce on November 23, V1159
Ori is apparently in superoutburst (vsnet-campaign-dn 3050). Clear
superhumps were detected by the Kyoto team on November 25 and 26
(vsnet-campaign-dn 3052). Using light curves taken by S. Kiyota,
K. Torii, K. Tanabe and the OUS team members, R. Ishioka, D. Nogami,
and M. Uemura, T. Kato detected an unusual phase reversal of the
superhumps occurred on November 28. On November 29, the strongest
signal is about 0.5 phase different from the strong superhump signal
which was observed before November 28. On November 28, this sudden
transition was followed in detail. This transition took only
several superhump cycles. The present observation strongly suggests
that the early phase reversal of the superhumps, which has been
first noted in ER UMa (Kato et al., astro-ph/0211520) is a common,
and possibly unique, feature in ER UMa stars (vsnet-campaign-dn
3064).
V436 Cen (RA = 11h13m58.2s, Dec = -37d40'45".0)
An outburst to 12.7mag was detected by A. Pearce on November 25.
The object further brightened to 11.9mag on November 27. It may be
a superoutburst (vsnet-campaign-dn 3054).
XX Dra (RA = 19h03m59s.18, Dec = +49d16'41".3)
A. de Ugarte Postigo et al. reported an outburst of the poorly
known variable star XX Dra (I~8mag) on November 28. It was still in
outburst on November 29. This implies an ongoing outburst with an
amplitude of at least 4 magnitudes (vsnet-campaign-mira 32).
RX Cha (RA = 10h36m26s.33, Dec = -80d02'48".2)
As reported by R. Stubbings on December 1 (14.5mag), the supposed
SU UMa-type dwarf nova is undergoing an outburst. The last outburst
(superoutburst?) was in 2002 April (vsnet-campaign-dn 3065).
(continuous targets)
SN 2002ap (RA = 01h36m23s.85, Dec = +15d45'13".0)
The object was reported to have experienced a sudden rapid fading
on November 26 (vsnet-campaign-sn2002ap 206).
SN 2002je (RA = 00h27m22s.42, Dec = +24d10'59".1)
Spectroscopic observations by the CfA team revealed that it was
type II SN near the maximum on Nov. 28 (vsnet-campaign-sn 509).
SN 2002jg (RA = 22h19m28s.80, Dec = +29d23'04".5)
Spectroscopic observations by the CfA team revealed that it was
type Ia SN at the maximum light on Nov. 28, with a notable reddening
(vsnet-campaign-sn 509).
QR And (RA = 00h19m49s.90, Dec = +21d56'52".1)
A possible deep fading to 13.3mag was reported on November 26
(vsnet-campaign-nl 102).
SN 2002hh (RA = 20h34m44s.29, Dec = +60d07'19".0)
The object was reported to be J=12.30 and Ks=11.07 on November
18 (vsnet-campaign-sn 510).
GSC 6846:6 (RA 18h03m14s.47, Dec = -25d14'22".1)
D. West showed their new observations and reported that the
maximum brightness occurred between October 17 to October 21
(vsnet-campaign-unknown 128).
RR Tau (RA = 05h39m30s.53, Dec = +26d22'26".3)
A fading to 12.7mag was again reported on November 23. The faint
state was still ongoing on November 24 (vsnet-campaign-orion 37).
MisV1147 (RA = 22h54m03s.78, Dec = +58d54'02".1)
A new fading was observed as expected from its quasi-periodicity.
The object started to fade on Nov. 27. On Nov. 28, the objected was
observed 1 mag fainter than two days before. T. Kato commented that
this observation may suggest that MisV1147 can be a rare deeply
eclipsing system among (likely) Herbig Ae/Be stars
(vsnet-campaign-unknown 129, 130). C. Lloyd commented that this
feature may well be a true eclipse but some Ae stars do show
Algol-like fades and this star clearly has other dramatic fades that
look like obscuration events (vsnet-campaign-unknown 131).
*** Future schedule ***
WEBT campaign on Mkn 421
M. Villata announced possible WEBT campaign on Mkn 421, in
December 2002 and February-March 2003, to be carried out during
multifrequency campaigns.
The relevant information on the MW campaign of December 2-16 is at
the VERITAS site <http://veritas.sao.arizona.edu> .
[vsnet-campaign-blazar 287]
[vsnet-campaign-blazar 288]
MINE OBSERVATIONS OF CYG X-1
F. Mirabel announced that the INTEGRAL satellite will point to
Cygnus X-1 for 1 million seconds between November 24 and December
6. In the context of the "MINE" collaboration
(http://elbereth.obspm.fr/~fuchs/mine.html), monitoring programs are
recommended for this period.
[vsnet-campaign-xray 166]
For further information, please, be in contact with Yael Fuchs
(yfuchs@discovery.saclay.cea.fr).
Texas in Tuscany
XXI Symposium on Relativistic Astrophysics
Florence, Italy, December 9-13, 2002
For more information:
http://vsnet.arcetri.astro.it/~texaflor/
[vsnet-campaign-xray 142]
SUPERNOVAE (10 YEARS OF SN1993J)
22-26 April 2003, Valencia, Spain
Web site: http://vsnet.uv.es/2003supernovae/
[vsnet-campaign-sn 342]
[vsnet-campaign-sn 452]
*** General information ***
(This summary can be cited.)
Regards,
Makoto Uemura
Return to Daisaku Nogami
vsnet-adm@kusastro.kyoto-u.ac.jp
VSNET Home Page