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[vsnet-campaign-news 194] News from VSNET
*** News from VSNET ***
The radio and infrared counterparts of the new X-ray transient,
XTE J1720-318 were discovered. OY Car is now rebrightening.
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 January 27, 2003, as VSNET campaign
circulation 1366
[Note a large part of detailed information is posted to vsnet-campaign
sub-lists].
VSNET Weekly Campaign Summary
*** Last week news ***
(new targets)
EP Car (RA = 10h28m23s.21, Dec = -58d57'58".6)
R. Stubbings reported an outburst (14.6mag) of the dwarf nova EP Car
o n January 22. This object has been suspected to be an SU UMa-type
dwarf nova. The last reported outburst occurred in 2002 June
(vsnet-campaign-dn 3343). The data by T. Richards on January 23
look rather flat, in contrast to the 2000 observation
(vsnet-campaign-dn 3345, 3347).
SN 2003O (RA = 03h38m09s.13, Dec = +40d58'38".0)
A host galaxy of SN 2003O is UGC 2798, a tilted open-spiral galaxy
near the Galactic plane. The SN is superimposed on the outermost
arm. The expected maximum for typical SN Ia is mag about 16.4
(vsnet-campaign-sn 542). The CfA team revealed that it is a type II
SN (vsnet-campaign-sn 544).
OY Car (RA = 10h06m22s.46, Dec = -70d14'04".4)
R. Stubbings detected an outburst (12.2mag) of the eclipsing SU
UMa-type dwarf nova, OY Car on January 23. The last outburst
(superoutburst) occurred in 2002 May (vsnet-campaign-dn 3346).
After temporary fading, the object experienced rebrightening to
11.9mag on January 27, as reported by R. Stubbings, which implies
that it is a superoutburst (vsnet-campaign-dn 3349, 3351).
SN 2003P (RA = 08h01m15s.63, Dec = +55d44'34".8)
A host galaxy of SN 2003P is a small galaxy interacting with MCG
+09-13-105. The expected maximum for typical SN Ia is mag around 17
(vsnet-campaign-sn 543).
(continuous targets)
XTE J1720-318 (RA = 17h19m58s.99, Dec = -31d45'01")
According to IAUC 8054, Rupen et al. detected a new radio source,
which is likely the counterpart of XTE J1720-318. The position is
1'.4 from the original X-ray position (vsnet-campaign-xray 181).
G. Tsarevsky reported no new optical source can be seen at the
position of the radio counterpart in the published catalogue with
the limit to R= ~20.0; B = ~21.0 and the image taken by B. Monard
with R >= ~18.0 (vsnet-campaign-xray 182). D. Kato et al., the IRSF
team of Nagoya Univ., reported a candidate of the infrared
counterpart (K=15.3 on January 18) (vsnet-campaign-xray 183).
According to ATEL #117, K. O'Brien et al. reported confirmation of
the suggested infrared counterpart (vsnet-campaign-xray 185).
HT Cam (RA = 07h57m01s.2 Dec = +63d06'00")
The observation by Nakajima-san covered the very important
transition from a plateau-like stage to a rapid decline stage.
During the early half of the observation, the object showed
large-amplitude slow modulation (and IP-type oscillation, of
course). At later times, the object even showed a 1 mag decline in
1 hour (vsnet-campaign-ip 102, vsnet-campaign-dn 3337). R. Ishioka
performed period analysis, and reported that the short-term
modulation in the early stage of the outburst showed a period of
0.00593(+/-0.00001) d, which was also detected during the last
outburst (vsnet-campaign-dn 3341, vsnet-campaign-ip 105). A rapid
fading to 15mag was reported by K. Torii on January 21
(vsnet-campaign-ip 104, vsnet-campaign-dn 3339). The object
had faded from the last outburst (vsnet-campaign-ip 103, 106, 107
vsnet-campaign-dn 3338, 3342, 3350).
AT Cnc (RA = 08h28m36s.92, Dec = +25d20'02".6)
The standstill continues (vsnet-campaign-dn 3340).
rho Cas (RA = 23h54m22s.99, Dec = +57d29'58".7)
Recently reported observations imply that rho Cas is now brighter
than usual (4.2-4.4mag) (vsnet-campaign-rhocas 11).
GZ Cnc (RA = 09h15m51s.70, Dec = +09d00'50".2)
The observation by K. Torii on January 15 showed that GZ Cnc
underwent an outburst at that time. The most notable feature during
this outburst was the presence of 0.15-mag modulations. The
modulations seem to have a characteristic time-scale of ~2 hr, which
is close to the orbital period. No strong short-term variations,
which were prominent during the past outbursts, were observed.
These finding may indicate that the characteristics of the Jan. 15
were different from those of the other outbursts (vsnet-campaign-dn 3344).
SN 2003L (RA = 11h03m12s.33, Dec = +11d04'38".3)
The Asiago group showed that it was SN Ic a few days after maximum
on Jan. 25.00 (vsnet-campaign-sn 544).
SN 2003M (RA = 12h13m21s.00, Dec = +21d38'48".4)
The Asiago team reported that the spectrum of SN 2003M taken on
Jan. 25.00 UT showed a strong resemblance with SN Ic 1994I. The SN
is physically associated with UGC 7224, though it is very far (about
30kpc) from its nucleus. SN Ic is thought to be a core-collapse
one, and such core-collapse SN in an early-type galaxy is very
exceptional (vsnet-campaign-sn 544).
HadV98 (RA = 17h23m14s.5, Dec = -22d52'05")
According to AAS #17.11 (Hasselbach et al.), HadV98 has been
confirmed to be an indeed R CrB star (vsnet-campaign-rcb 89).
V803 Cen (RA = 13h23m44s.5, Dec = -41d44'30".1)
The bright, oscillating state still continues (vsnet-campaign-dn 3348).
MisV1147 (RA = 22h54m03s.78, Dec = +58d54'02".1)
The object was further fading on January 20 and 21
(vsnet-campaign-unknown 176, 179).
MKN 421 (RA = 11h04m27s, Dec = +38d12'32")
It is fading from the last outburst (vsnet-campaign-blazar 296).
*** Future schedule ***
eta Car: The next "shell event"/X-ray eclipse
M. Corcoran reported the event will occur this summer.
Coordinated ground-based observations of eta car along with the
X-ray observations would be really important.
For more information:
Latest X-ray light curve:
http://lheawww.gsfc.nasa.gov/users/corcoran/eta_car/etacar_rxte_lightcurve/
[vsnet-campaign-sdor 23]
[vsnet-campaign-xray 172]
Light curve provided by S. Otero:
http://ar.geocities.com/varsao/Curva_Eta_Carinae.htm
[vsnet-campaign-sdor 22]
The 2003 Gamma Ray Burst conference
Hosted by Los Alamos,
in Santa Fe, New Mexico (USA), between September 8 and 12, 2003
http://grb2003.lanl.gov/
[vsnet-campaign-grb 13]
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]
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]
[vsnet-campaign-sn 512]
*** General information ***
XTE J1720-318
Infrared counterpart detected by D. Kato et al.
http://vsnet.kusastro.kyoto-u.ac.jp/vsnet/Xray/xtej1720.html
[vsnet-campaign-xray 184]
MisV1147
MISAO page:
http://vsnet.aerith.net/misao/variable/MisV1147.html
[vsnet-campaign-unknown 177, 178]
DI UMa
Time-series data provided by L. Kral, see [vsnet-campaign-data 106]
HadV98
Past articles posted to VSNET, see [vsnet-campaign-rcb 90]
V838 Mon
Color image by L. Crause:
http://mensa.ast.uct.ac.za/~lcrause/January.html
[vsnet-campaign-v838mon 414]
OY Car
Eclipse ephemeris, see [vsnet-campaign-dn 3346]
(This summary can be cited.)
Regards,
Makoto Uemura
Return to Daisaku Nogami
vsnet-adm@kusastro.kyoto-u.ac.jp
VSNET Home Page