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[vsnet-campaign-news 146] News from VSNET
*** News from VSNET ***
DV UMa, a deeply eclipsing SU UMa-type dwarf nova, is now in
a relatively rare superoutburst.
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 April 15, 2002, as VSNET campaign circulation 1302
[Note a large part of detailed information is posted to vsnet-campaign
sub-lists].
VSNET Weekly Campaign Summary
*** Last week news ***
(new targets)
DV UMa (RA = 09h46m36s.67, Dec = +44d46'45".1)
As detected by J. Pietz on April 9, the eclipsing SU UMa-type
dwarf nova DV UMa is now in superoutburst (vsnet-campaign-dn 2280).
The superoutburst is still ongoing (vsnet-campaign-dn 2282, 2288,
2292). M. Uemura reported that eclipses on April 9 had two
components, one was presumably of a disk and the other was probably
of a white dwarf or a very bright region in an inner accretion disk
(vsnet-campaign-dn 2297, 2299, 2302).
V342 Cen (RA = 11h07m15s.82, Dec = -55d57'32".7)
R. Stubbings reported an outburst (14.4mag) on April 8.
This star is a recently recognized UG star (vsnet-campaign-dn 2283).
SN 2002cb (RA = 13h04m23s.97, Dec = +47d35'53".2)
T. Boles discovered SN 2002cb at 17.0mag in the image taken
on April 7. The spectrum of SN 2002cb taken by the UCB team
revealed that it is of type IIn. The expected maximum for typical
SN Ia is similar to the discovery magnitude, so it belongs the
bright class of SN IIn (vsnet-campaign-sn 404, 407).
BF Ara (RA = 17h38m10s.40, Dec = -47d10'43".4)
An outburst (14.3-14.4mag) was detected by R. Stubbings on
April 8. The object is possibly related to ER UMa stars
(vsnet-campaign-dn 2285).
SN 2002cc (RA = 08h34m01s.97, Dec = +55d39'12".4)
SN 2002cc was discovered at 18.5mag in images taken on April 4
and 9 by the LOTOSS team. The host galaxy of SN 2002cc is an
anonymous galaxy near UGC 4470. It seems to belong the group
WBL 184, but the distance is uncertain (vsnet-campaign-sn 405).
It is type Ia SN about a week after maximum on Apr. 10
(vsnet-campaign-sn 407).
SN 2002cd (RA = 20h23m34s.42, Dec = +58d20'47".4)
M. Armstrong discovered SN 2002cd at 17.5mag on an image taken
on April 8. NGC 6916, the host galaxy of SN 2002cd, is somewhat
nearby galaxy, but affected notable Galactic reddening. The
expected maximum for typical SN Ia is mag about 16.0 in R
(vsnet-campaign-sn 405). According to IAUC 7873, The CfA team
took a spectrum of SN 2002cd, which revealed that it is a type Ia
SN about 10 days before maximum (vsnet-campaign-sn 407).
V893 Sco (RA = 16h14m45s.26, Dec = -28d39'30".3)
R. Stubbings reported an outburst (12.6mag) of V893 Sco
on April 10 (vsnet-campaign-dn 2289). The object was reported to
fade to 13.0 and 13.5 mag on April 11 and 14, respectively.
The duration of the outburst is possibly long (vsnet-campaign-dn
2293, 2306).
L2 Pup (RA = 07h13m31s.82, Dec = -44d38'38".9)
The object is recovering from the faint minimum
(vsnet-campaign-mira 23).
AM Her (RA = 18h16m13s.4, Dec = +49d52'03".1)
The object is still in a faint state (vsnet-campaign-polar 3).
SN 2002ce (RA = 08h33m22s.1, Dec = +29d32'01")
R. Arbour discovered SN 2002ce at 16.0-16.5mag on an image taken
on April 10. The position of SN 2002ce is about 12" west and 18"
south of the 2MASS position of the center of NGC 2604, a somewhat
nearby spiral galaxy with a complicated central region. This SN is
spectroscopically classified by the CfA team as of normal type II,
in the early phase. In average, normal SN II is about 2 mag dimmer
than the typical SNeIa, so the expected maximum of this SN is mag
about 15.9 (vsnet-campaign-sn 408).
V485 Cen (RA = 12h57m23s.30, Dec = -33d12'06".8)
An outburst (14.8mag) was reported by R. Stubbings on April 14.
It may be a superoutburst (vsnet-campaign-dn 2303).
Red variable near XTE J1751-305
(RA = 17h51m16s.13, Dec = -30d37'59".2)
According to IAUC 7872, a variable star near the millisec
pulsar XTE J1751-305 turns out to be of late-M spectral type.
The 2MASS K magnitude is 7.65 +/- 0.04 with J-K color of 2.0,
consistent with a red (or reddened) star (vsnet-campaign-xray 128).
Therefore, it is most likely not the counterpart of XTE J1751-305.
RX J1643.7+3402 (RA = 16h43m45s.1, Dec = +34d02'35")
M. Richmond performed a time-series observation of this object,
and reported that the star varies with an amplitude of up to
0.3 mag, on time scales of 10-30 minutes (vsnet-campaign-dn 2300).
V2051 Oph (RA = 17h08m19.1s, Dec = -25d48m31.1s)
An outburst (14.5mag) was reported on April 14 by R. Stubbings
(vsnet-campaign-dn 2305).
SN 2002cf (RA = 12h54m31s.30, Dec = -06d51'24".8)
SN 2002cf was discovered at 17.0mag on an image taken on
April 13 by the LOTOSS team. The host galaxy of SN 2002cf is
NGC 4786, an elliptical galaxy with some peculiarity. The SN is
about 16" west and 9" north of the nucleus of NGC 4786. Such
elliptical galaxies only produce SN Ia. The expected maximum for
typical SN Ia is mag about 15.7 (vsnet-campaign-sn 410).
SN 2002cg (RA = 16h29m00s.48, Dec = +41d17'00".4)
SN 2002cg was discovered at 17.8mag on an image taken on
April 13 by the LOTOSS team. The host galaxy of SN 2002cg =
UGC 10415 is somethat distant one. The expected maximum for
typical SN Ia is mag about 17.2 (vsnet-campaign-sn 410).
(continuous targets)
RX J1155.4-5641 (RA = 11h55m27s.0, Dec = -56d41'53")
The superoutburst seems to have finished around April 11
(vsnet-campaign-dn 2284, 2295).
SN 2002bw (RA = 17h16m35s.60, Dec = -10d20'31".8)
IAUC 7872 informed that this SN is of type Ia about 3 weeks
after maximum on Apr. 4.49 (vsnet-campaign-sn 406).
MKN 421 (RA = 11h04m27s, Dec = +38d12'32")
The object started fading from the recent burst
(vsnet-campaign-blazar 258).
XTE J1908+094 (RA = 19h08m53s.077, Dec = +09d23'04".90)
According to IAUC 7874, Rupen et al. detected a possible radio
counterpart of this X-ray nova at the above position. According
to ATEL #86, Wagner and Starrfield report that they could not
find an optical counterpart brighter than R ~ 23
(vsnet-campaign-xray 130).
V589 Her (RA = 16h22m07s.19, Dec = +19d22'36".3)
T. Vanmunster reported a revised superhump period to be
0.0947 +/- 0.0005 d. This turns V589 Her into a UGSU type dwarf
nova inside the so called 'period gap' (vsnet-campaign-dn 2291).
The object rapidly faded on April 7/8 (vsnet-campaign-dn 2287).
CR Boo (RA = 13h48m55s.42, Dec = +07d57'30".3)
An outburst at 13.8mag was reported on April 12 by M. Simonsen
(vsnet-campaign-dn 2294).
SN 2002bz (RA = 14h24m40s.52, Dec = +26d37'34".7)
It turned out to be of type Ia near maximum on Apr. 5
(vsnet-campaign-sn 407).
SN 2002ca (RA = 13h32m31s.51, Dec = +01d50'42".5)
It turned out to be a normal type II SN in the early phase
on Apr. 5 (vsnet-campaign-sn 407).
UV Gem (RA = 06h38m44s.16, Dec = +18d16'11".5)
The superoutburst continues (vsnet-campaign-dn 2286).
T. Vanmunster detected superhumps whose period was calculated
to be 0.0926 +/- 0.0010 d. This is slightly longer than that
he reported during 1999 December outburst (vsnet-campaign-dn 2301).
SN 2002bu (RA = 12h17m37s.18, Dec = +45d38'47".4)
The object remains at about R~15.5mag (vsnet-campaign-sn 409).
KS UMa (RA = 10h20m26s.54, Dec = +53d04'33".5)
The superoutburst still continues (vsnet-campaign-dn 2296).
GZ Cnc (RA = 09h15m51s.70, Dec = +09d00'50".2)
The object again experienced an outburst at 13.3mag as reported
by R. Stubbings on April 14. The outburst cycle has recently
been very short (vsnet-campaign-dn 2304).
GK Per (RA = 03h31m12s.50, Dec = +43d54'17".8)
The object appears to have been past the maximum of this outburst
(vsnet-campaign-gkper 83, 84).
V2540 Oph (RA = 17h37m34s.36 Dec = -16d23'18".4)
The object again brightened to 8.4mag on April 7
(vsnet-campaign-nova 900).
OJ287 (RA = 08h51m57s, Dec = 20d17'59")
The object was reported to be fading slightly
(vsnet-campaign-blazar 257).
V838 Mon (RA = 07h04m04s.816, Dec = -03d50'50".94)
The fading still continues and the object is now in 9th mag
(vsnet-campaign-v838mon 331, 332, 333, 334, 335, 336, 337, 339).
M. Fujii performed spectroscopy and reported that there seem to
be emerging characteristics of an M-type spectrum
(vsnet-campaign-v838mon 338).
HL CMa (RA = 06h45m17s.0, Dec = -16d51'35")
The standstill continues (vsnet-campaign-dn 2307).
RR Tau (RA = 05h39m30s.53, Dec = +26d22'26".3)
The object is now fading. Observations of 11.3-11.9 mag have
been reported recently (vsnet-campaign-orion 31).
CI Cam (RA = 04h19m42s.08, Dec = +55d59'57".8)
M. Uemura reported that CI Cam had been gradually brightening
since the early April (vsnet-campaign-xray 131, vsnet-campaign-be
179). The object then became 0.1mag fainter on April 14 than
that on April 12 (vsnet-campaign-xray 132, vsnet-campaign-be 180).
*** Future schedule ***
NEW X-RAY RESULTS FROM CLUSTERS OF GALAXIES AND BLACK HOLES
34th COSPAR Scientific Assembly
10th to 12th October 2002 - Houston, Texas
For more information, visit the session website:
www.mssl.ucl.ac.uk/www_astro/cospar
[vsnet-campaign-xray 124]
[vsnet-campaign-agn 2]
SUPERNOVAE (10 YEARS OF SN1993J)
22-26 April 2003, Valencia, Spain
Web site: http://vsnet.uv.es/2003supernovae/
[vsnet-campaign-sn 342]
34TH COSPAR - GRB AFTERGLOW PHYSICS
HOUSTON, TX, USA, 10-19 OCTOBER 2002
Main Scientific Organizer (MSO):
Elena Pian - INAF, Astronomical Observatory of Trieste, Italy -
pian@ts.astro.it
http://vsnet.ts.astro.it/topics/topix.html
[vsnet-campaign-grb 1]
MASS-LOSING PULSATING STARS AND THEIR CIRCUMSTELLAR MATTER
Sendai, Japan: May 13-16, 2002
contact to: Dr. M. Seki or wsloc@astr.tohoku.ac.jp
http://vsnet.astr.tohoku.ac.jp/ws2002/
[vsnet-campaign-mira 3]
International Conference on Classical Nova Explosions
Sitges (Barcelona), Spain: 20-24 May 2002
For more detailed information, see http://vsnet.ieec.fcr.es/novaconf
[vsnet-campaign-nova 643]
[vsnet-campaign-nova 666]
Blazar meeting at Tuorla: June 17-21, 2002
for more information, see http://vsnet.astro.utu.fi/blazar02
[vsnet-campaign-blazar 232]
*** General information ***
GK Per
Time-series photometry by M. Kolasa, see [vsnet-campaign-data 94]
DV UMa
Eclipse ephemeris, see [vsnet-campaign-dn 2281]
Light curves provided by J. Pietz:
8/9 April rising part
http://home.t-online.de/home/Jochen.Pietz/dvuma1.gif
9/10 April first indications of humps
http://home.t-online.de/home/Jochen.Pietz/dvuma2.gif
10/11 April overlapping humps and eclipses
http://home.t-online.de/home/Jochen.Pietz/dvuma3.gif
11/12 April separated humps and eclipses
http://home.t-online.de/home/Jochen.Pietz/dvuma4.gif
[vsnet-campaign-dn 2298]
V838 Mon
B-band image provided by F. Hormuth:
http://vsnet.byte-o-matic.net/v838mon_b_20020409.gif
[vsnet-campaign-v838mon 330]
Spectrum taken by M. Fujii:
http://vsnet1.harenet.ne.jp/~aikow/v838_0412.gif
[vsnet-campaign-v838mon 338]
V893 Sco
Eclipse ephemeris, see [vsnet-campaign-dn 2290]
RXJ1643.7+3402
Time-series observation by M. Richmond:
http://spiff.rit.edu/richmond/ritobs/apr11_2002/apr11_2002.html
http://spiff.rit.edu/richmond/ritobs/apr11_2002/rx_apr12ut.dat
[vsnet-campaign-dn 2300]
V2540 Oph
Spectrum taken by M. Fujii:
http://vsnet1.harenet.ne.jp/~aikow/v2540_0412.gif
[vsnet-campaign-nova 901]
(This summary can be cited.)
Regards,
Makoto Uemura
vsnet-adm@kusastro.kyoto-u.ac.jp
Return to Daisaku Nogami
vsnet-adm@kusastro.kyoto-u.ac.jp
VSNET Home Page