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[vsnet-campaign-news 187] News from VSNET
*** News from VSNET ***
The supercycle of Var73 Dra turned out to be exceptionally short.
A relatively rare superoutburst of CU Vel is now ongoing.
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 16, 2002, as VSNET campaign
circulation 1353
[Note a large part of detailed information is posted to vsnet-campaign
sub-lists].
VSNET Weekly Campaign Summary
*** Last week news ***
(new targets)
CU Vel (RA = 08h58m32s.87, Dec = -41d47'50".8)
As detected by R. Stubbings on December 10, the SU UMa-type dwarf
nova CU Vel is now in outburst (vsnet-campaign-dn 3110, 3112). In
the light curve taken by G. Bolt on December 11, clear superhumps
were detected. In addition to superhumps, there was strong evidence
of super-QPOs with relatively large amplitudes. The light curve
just looks like the first night observation of the superoutburst of
EF Peg in 1991. T. Kato commented that the similarity of the
pattern of super-QPOs and early-stage superhumps with that of EF Peg
may suggest these features may be closely associated with
long-period SU UMa-type dwarf novae with relatively rare
superoutbursts (vsnet-campaign-dn 3126). On December 14, the
superhumps have fully grown with an amplitude of 0.25 mag.
Prominent super-QPO-type signal on Dec. 11 looks like to have
disappeared. A preliminary analysis of the data by T. Kato yielded
a superhump period of 0.0809-0.0811 d (vsnet-campaign-dn 3129,
3136). The superoutburst is now ongoing (vsnet-campaign-dn 3130,
3134).
DI UMa (RA = 09h12m22s.16, Dec = +50d49'39".1)
An outburst to 14.9mag was reported by G. Poyner on December 10
(vsnet-campaign-dn 3116). Clear superhumps (0.2 mag) were detected
on K. Tanabe's data on Dec. 12 (vsnet-campaign-dn 3123, 3127).
SN 2002jm (RA = 10h19m25s.20, Dec = -05d39'14".5)
IC 603, a host galaxy of SN 2002jm, is a disk galaxy. The SN is
superimposed on the bright bulge region. The expected maximum for
typical unreddened SN Ia is mag about 16.1, which seems not the
case (vsnet-campaign-sn 517). It seems to be a subluminous SN Ia
about 3 weeks after maximum (vsnet-campaign-sn 519).
SN 2002jn (RA = 20h11m59s.91, Dec = +05d31'16".0)
UGC 11523, a host galaxy of SN 2002jn, is a face-on open spiral
galaxy with a low b (= -15deg). The SN is superimposed on the
outer arm. The expected maximum for typical unreddend (within the
host galaxy) SN Ia is mag about 16.4 (vsnet-campaign-sn 517).
IW And (RA = 01h01m08s.82, Dec = +43d23'27".3)
The object may have been in a standstill since the end of November
(vsnet-campaign-dn 3119).
SN 2002jo (RA = 14h38m16s.42, Dec = +40d27'14".0)
NGC 5708, a host galaxy of SN 2002jo, is a late spiral galaxy.
The expected maximum for typical SN Ia is mag about 14.5 when
unreddened within the host galaxy. The UCB team took a spectrum of
it on Dec. 12 UT, which revealed that it is a reddened SN Ia about 3
weeks after maximum (vsnet-campaign-sn 518).
SN 2002jp (RA = 10h37m26s.50, Dec = -25d21'35".2)
NGC 3313, a host galaxy of SN 2002jp, is a barred-spiral galaxy
with a ring structure. The SN is located well outside of the
spiral arm. The UCB team took a spectrum of this SN, and revealed
that it is a type Ic SN about 2 week after maximum
(vsnet-campaign-sn 518). B. Monard reported his prediscovery
observations, which show the SN was already bright on November 12 at
17.7CR (vsnet-campaign-sn 520).
1RXS J232953.9+062814 (RA = 23h29m54s.30, Dec = +06d28'10".9)
The Kyoto team reported an outburst of this ultrashort period
dwarf nova. It was about 13.2mag on December 13, and rapidly faded
(vsnet-campaign-dn 3124).
BB Vel (RA = 08h36m49s, Dec = -47d22'39")
A bright outburst was reported on December 7 (vsnet-campaign-dn
3131).
(continuous targets)
V1028 Cyg (RA = 20h00m52.13s, Dec = +56d56'22.3")
M. Uemura reported that it was still bright on December 10, which
indicates that the current outburst is a superoutburst
(vsnet-campaign-dn 3101). The superoutburst is now ongoing
(vsnet-campaign-dn 3114, 3118, 3125).
AH Her (RA = 16h44m09s.99, Dec = +25d15'02".1)
The object is still in a standstill (vsnet-campaign-dn 3113).
GY Cnc (RA = 09h09m50s.5, Dec = +18d49'47")
The long outburst is still ongoing (vsnet-campaign-dn 3102, 3120).
eta Gem (RA = 06h14m52s.87, Dec = +22d30'24".5)
It is now faint in a possible eclipse. Observations of 3.2-3.9mag
were reported (vsnet-campaign-ecl 52).
IP Peg (RA = 23h23m08s.7, Dec = +18d24'59".1)
A possible outburst to 14.3mag was reported on December 9
(vsnet-campaign-dn 3103).
SN 2002jj (RA = 03h39m29s55, Dec = -13d06'55".8)
This SN was turned out to be a type Ic SN, about one month after
maximum on Dec. 12. Such a slow evolution of the light curve is
quite exceptional for type Ic SN. The follow-up magnitude estimates
is very urged (vsnet-campaign-sn 519).
V630 Cyg (RA = 21h34m59s.21, Dec = +40d40'18".5)
The superoutburst continues (vsnet-campaign-dn 3104).
V1113 Cyg (RA = 19h22m38s.62, Dec = +52d43'51".1)
The superoutburst continues (vsnet-campaign-dn 3105).
Var73 Dra (RA = 20h23m38s.193, Dec = +64h36m26s.91)
D. Starkey's observations confirmed that the current outburst is a
genuine superoutburst. This finding suggests that the minimum
supercycle length of Var73 Dra is around ~60 d (or possibly slightly
shorter). This shortness of the supercycle is comparable to those
of ER UMa-type dwarf novae. In conjunction with Antipin and
Pavlenko (2002) A&A 391, 565, the supercycle of this object may not
be as stable as in ER UMa stars. Such a variation of the
supercycles was also recorded in the in-the-gap SU UMa-type dwarf
nova, NY Ser (Nogami et al. 1998, PASJ 50, L1). Var73 Dra may be
the first ER UMa-like dwarf nova in the period gap (vsnet-campaign-dn
3100). T. Vanmunster performed a new time-series observation on
December 10/11, and detected well developed superhumps
(vsnet-campaign-dn 3107). He found a superhump period value of
0.1069 +/- 0.002. During his first 2 nights, no clear hints
of superhumps were present, and the average amplitude of the light
modulations was about 0.10 mag (vsnet-campaign-dn 3108, 3109).
The superoutburst is ongoing (vsnet-campaign-dn 3117, 3133).
HV Aur (RA = 04h53m16s.8, Dec = +38d16'29")
In the light curve taken by G. Masi on Nov. 30-Dec. 1, superhumps
and secondary humps are clearly detected on the descending branch
from the superoutburst (vsnet-campaign-dn 3128).
BL Lac (RA = 22h02m42s.86, Dec = +42d16'37".6)
The object experienced outburst again on December 13
(vsnet-campaign-blazar 290).
V1159 Ori (RA = 05h28m59s.52, Dec = -03d33'52".8)
The object has been fading from the last superoutburst
(vsnet-campaign-dn 3115).
Z Cha (RA = 08h07m16s.29, Dec = -76d32'20".9)
The superoutburst continues (vsnet-campaign-dn 3132).
MisV1147 (RA = 22h54m03s.78, Dec = +58d54'02".1)
D. West estimated the spectral class of the object to be B4V or
B2I from de-reddened color from the A. Henden's observation #1 and
A7V or F0I from the observation II (vsnet-campaign-unknown 152, 153,
154, 156, 159, 158). The object started recovering from the last
fading on December 12 (vsnet-campaign-unknown 155, 157, 162).
*** 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]
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 ***
GY Cnc
Eclipse ephemeris, see [vsnet-campaign-dn 3099, 3121]
IP Peg
Eclipse ephemeris, see [vsnet-campaign-dn 3106]
AY Psc
Eclipse ephemeris, see [vsnet-campaign-dn 3111]
Z Cha
Eclipse ephemeris, see [vsnet-campaign-dn 3122]
TmzV772
Chart for CCD observers presented by D. West:
http://members.aol.com/dwest61506/page39.html
Chart for visual observers presented by D. West:
http://members.aol.com/dwest61506/page40.html
[vsnet-campaign-unknown 161]
CU Vel
Outburst image taken by P. Nelson:
http://vsnet.kusastro.kyoto-u.ac.jp/pub/vsnet/DNe/CU_Vel/cunelson.gif
Outburst image taken by B. Heathcote:
http://vsnet.kusastro.kyoto-u.ac.jp/pub/vsnet/DNe/CU_Vel/heathcote.jpg
[vsnet-campaign-dn 3135]
(This summary can be cited.)
Regards,
Makoto Uemura
Return to Daisaku Nogami
vsnet-adm@kusastro.kyoto-u.ac.jp
VSNET Home Page