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*** News from VSNET ***
The microquasar, V4641 Sgr experienced a new outburst.
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 August 11, 2003, as VSNET campaign
circulation 1407
[Note a large part of detailed information is posted to vsnet-campaign
sub-lists].
VSNET Weekly Campaign Summary
*** Last week news ***
(new targets)
V4641 Sgr (RA = 18h19m21s.6, Dec = -25d24'25")
R. Stubbings reported that the microquasar V4641 Sgr experienced a
brightening to 12.1mag on August 1 (vsnet-campaign-v4641sgr 175,
vsnet-campaign-xray 243). He reported that the object once dropped
back to a faint state 2.6-hour after the brightening
(vsnet-campaign-v4641sgr 178, vsnet-campaign-xray 245). C. Bailyn
reported that it was slightly brighter than the normal state on
August 1 (vsnet-campaign-v4641sgr 181, vsnet-campaign-xray 247).
J. Swank reported that no X-ray brightening was detected on July
29 (vsnet-campaign-v4641sgr 177, vsnet-campaign-xray 244). D. Rupen
reported that no radio activity was detected on July 31
(vsnet-campaign-v4641sgr 176). On August 2 and 3, it was still at a
relatively faint, normal state (vsnet-campaign-v4641sgr 180, 182,
vsnet-campaign-xray 248).
D. Maitra reported that a new outburst (V=12.6) was detected on
August 4 (vsnet-campaign-xray 249, 251, vsnet-campaign-v4641sgr 183,
185). B. Monard observed short-term fluctuations with time scales
of a few minutes to an hour on August 4 (vsnet-campaign-v4641sgr
184, vsnet-campaign-xray 250). The light curve is characterized by
recurrent occurrences of gradual rise (with violent fluctuations) and
a sudden drop. The light curve, as a whole, resembles those of
violently varying state just after the beginning of the 2002 active
phase (vsnet-campaign-xray 252, vsnet-campaign-v4641sgr 186, 187).
The object was still bright on August 5 (vsnet-campaign-v4641sgr
189). C. Bailyn reported that, on August 6, the source was in a
highly active flaring state in the X-ray range, with flares of up to
100 mCrabs erupting on timescale of 10-30 seconds. Flares and dips
of several tenths of a magnitude were also observed in the optical
range on timescales of <3 minutes (vsnet-campaign-v4641sgr 192,
vsnet-campaign-xray 253). The 100-sec time-scale variations were
also reported by M. Uemura (vsnet-campaign-v4641sgr 194). On August
6, there was an apparent "optical flash", which is similar to the
event observed on 2002 July 7 (vsnet-campaign-v4641sgr 198).
I. Khamitov reported that the power spectrum of the optical
variations could be described by a power law with the slope -1.8 in
the frequency band 1e-4 - 0.04 Hz (vsnet-campaign-v4641sgr 197).
The object started fading on August 7. During the fading phase,
~1-mag flares were observed (vsnet-campaign-v4641sgr 200, 204).
These behavior just before the maximum is quite analogous to that
observed during the last active state in 2002
(vsnet-campaign-v4641sgr 208). The object now remains at
(temporary?) faint state. Close monitoring is still encouraged
(vsnet-campaign-v4641sgr 179, 193, 202, 203, 207).
SN 2003gs (RA = 02h27m38s.36, Dec = -01d09'35".4)
As reported on IAUC 8171, R. Evans visually discovered a bright
supernova, SN 2003gs, in NGC 936. The discovery magnitude was mag
14.0 on July 29.75 UT, and confirmed at visual mag 13.8 on the
following night (July 30.75 UT). The position of new object is
about 13" east and 15" south of the center of NGC 936, a
barred-spiral galaxy. The CTIO spectrum taken on July 30.4 revealed
that it was type Ia supernova, about a week after maximum light
(vsnet-campaign-sn 663, 664, 665).
SN 2003gr (RA = 23h38m12s.67, Dec = -20d46'56".0)
SN 2003gr is hosted by MCG -04-55-14, a barred-spiral galaxy. The
expected maximum for typical SN Ia is consistent with the discovery
magnitude (16.3-16.4 mag).
SN 2003gt (RA = 20h32m59s.12, Dec = +09d52'19".3)
SN 2003gt is hosted by NGC 6930, a nearly edge-on barred-spiral
galaxy. The expected maximum for typical SN Ia is mag about 16.0
(vsnet-campaign-sn 665). A spectrum taken by the UCB team on Aug. 5
UT revealed that it was indeed a type Ia SN near maximum
(vsnet-campaign-sn 667).
AY Lac (RA = 22h22m23s.3, Dec = +50d23'29")
According to IBVS No. 5441, Kroll et al. concluded that AY Lac is
most likely a cataclysmic variable, by confirming the outburst
detection on the archival plates. They suggested that the object
may be either a recurrent nova or a WZ Sge-like object
(vsnet-campaign-dn 3881).
SN 2003gu (RA = 23h02m59s.45, Dec = +34d43'19".6)
SN 2003gu is hosted by UGC 12331, a dim spiral galaxy. The
expected maximum for typical SN Ia is mag about 16.3
(vsnet-campaign-sn 666). The UCB team revealed that it was a young
type II (possibly type IIb) supernova, based on a spectrum taken on
Aug. 5 UT (vsnet-campaign-sn 667).
SN 2003gv (RA = 01h08m53s.18, Dec = +32d05'59".3)
SN 2003gv is hosted by MCG +05-3-66, an apparent spiral galaxy.
The expected maximum for typical SN Ia is mag about 17.5
(vsnet-campaign-sn 667).
SN 2003gw (RA = 05h11m47s.68, Dec = +67d29'22".2)
SN 2003gw is hosted by UGC 3252, a face-on open spiral galaxy.
The expected maximum for typical SN Ia is mag about 16.6
(vsnet-campaign-sn 668).
SAX J2103.5+4545 (RA = 21h03m35s.74, Dec = +45d45'05".6)
According to ATEL #173, Reig and Mavromatakis report that a GSC
star with 13.04mag (GSC3588.834) is probably identified with the
transient X-ray pulsar SAX J2103.5+4545. The object is likely a
Be/X-ray binary (vsnet-campaign-xray 255).
SN 2003gx (RA = 01h02m55s.09, Dec = +37d40'10".3)
SN 2003gx is hosted by MCG +6-3-7, a faint spiral galaxy. The
expected maximum for typical SN Ia is mag about 17.5
(vsnet-campaign-sn 669).
SU Tau (RA = 05h49m03s.7, Dec = +19d04'21")
The observation by J. Gunther on August 9 indicates a onset of a
fading (vsnet-campaign-rcb 147).
(continuous targets)
V660 Her (RA = 17h42m07s.3, Dec = +23d47'37".3)
P. A. Dubovsky reported an outburst (14.6mag) of the SU UMa-type
dwarf nova V660 Her on July 27. The outburst seems to have been
confirmed by Dan Taylor (vsnet-campaign-dn 3880). D. Nogami has
informed that V660 Her was fainter than Rc=16.6 on July 31. The
outburst seems to be a short outburst (vsnet-campaign-dn 3883).
SN 2003gn (RA = 22h33m51s.68, Dec = +20d48'08".5)
The UCB group (Jul. 27 UT) and the CfA group (Jul. 29.37 UT)
showed that it was type Ia SN near maximum (vsnet-campaign-sn 662).
SN 2003go (RA = 19h52m47s.68, Dec = -19d11'28".2)
A Baade spectrum of SN 2003go taken on July 30.30 UT showed that
it is type IIn SN. It seems to be somewhat further than ESO
595-G001 (vsnet-campaign-sn 668).
VW CrB (RA = 16h00m03s.76, Dec = +33d11'14".4)
From the data received by the VSNET Collaboration up to July 31,
T. Kato reported the best superhump period to be 0.07272(2) d. This
value is significantly shorter than the literature value (Novak
1997, IBVS 4489) (vsnet-campaign-dn 3882, 3884).
SN 2003gp (RA = 16h03m55s.47, Dec = +25d00'24".8)
The UCB group (Jul. 27) confirmed that it was a young type II SN
(vsnet-campaign-sn 662).
SN 2003gq (RA = 22h53m20s.68, Dec = +32d07'57".6)
The UCB team (Jul. 27) showed that it was type Ia SN near or
slightly before maximum; they quote that it resembles that of
peculiar (bright) SN Ia 1991T (vsnet-campaign-sn 662).
V2051 Oph (RA = 17h08m19.1s, Dec = -25d48'31".1)
The object experienced a relatively bright (13.8mag) outburst on
August 1 (vsnet-campaign-v2051oph 47).
RS Oph (RA = 17h50m13s.56, Dec = -06d42'30".6)
I. Bryukhanov reported an outburst of RS Oph in 1958 July recorded
in the Odessa photograph collection (vsnet-campaign-nova 1357).
*** Future schedule ***
International Conference "Interacting Binary Stars-2003"
Odessa, Ukraine, August 18-22, 2003
http://oap16.pochta.ru
Contact address: Prof. Ivan L.Andronov, oap16@pochta.ru
X-Ray Timing 2003: Rossi and Beyond
November 3-5, 2003
Harvard-Smithsonian Center for Astrophysics
http://hea-www.harvard.edu/xrt2003/
[vsnet-campaign-xray 242]
AR UMa and AM Her campaign with the HST
TOO program conducted by S. Saar and F. Ringwald
see [vsnet-campaign-polar 24]
WEBT Campaign for AO 0235+16 with XMM-Newton
January-February 2004
please contact to Claudia M. Raiteri,
see [vsnet-campaign-blazar 301]
Multiwavelength AGN Surveys
a "Guillermo Haro" Astrophysics Conference
organized by INAOE
December 8-12, 2003
Cozumel, Mexico
http://vsnet.inaoep.mx/~agn2003/
[vsnet-campaign-agn 4]
IM Nor Campaign
by I. Hachisu (University of Tokyo) and the VSNET team
For more information, see [vsnet-campaign-nova 1241]
GRB Mini-Symposium in JENAM2003
For more information, http://vsnet.konkoly.hu/jenam03/
[vsnet-campaign-grb 31]
Conference: THE INTERPLAY AMONG BLACK HOLES, STARS AND ISM IN
GALACTIC NUCLEI
in Gramado, south of Brasil, March 1-5, 2004
for more information, please contact to BHSIGN@if.ufrgs.br
[vsnet-campaign-agn 3]
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, 24,
25, 26, 28, 29, 46]
[vsnet-campaign-xray 172]
Light curve provided by S. Otero:
http://ar.geocities.com/varsao/Curva_Eta_Carinae.htm
[vsnet-campaign-sdor 22, 32, 33]
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]
*** General information ***
V4641 Sgr
VSNET page:
http://vsnet.kusastro.kyoto-u.ac.jp/vsnet/Xray/v4641sgr03.html
[vsnet-campaign-v4641sgr
188, 190, 191, 199, 201]
M. Rupen's observation schedule page:
http://vsnet.aoc.nrao.edu/~mrupen/XRT/V4641Sgr/v4641sgr.shtml
[vsnet-campaign-v4641sgr 196,
vsnet-campaign-xray 254]
T. Scarmato's page:
http://toniscarmato.interfree.it/sgrv4641.htm
[vsnet-campaign-v4641sgr 206]
Preprint by Uemura, et al. in astro-ph/0308154
[vsnet-campaign-v4641sgr 205]
V4743 Sgr
Preprint by J.-U. Ness, et al. in astro-ph/0308017
[vsnet-campaign-nova 1356]
V Sge
Preprint by I. Hachisu and M. Kato in astro-ph/0308065
[vsnet-campaign-nl 135]
NMO Digest for August: see [vsnet-campaign-mira 69, 70]
(This summary can be cited.)
Regards,
Makoto Uemura
Return to the Daisaku
vsnet-adm@kusastro.kyoto-u.ac.jp
