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[vsnet-campaign-news 162] News from VSNET
*** News from VSNET ***
Superhumps of KK Tel were detected. This observation confirmed
the long-suspected SU UMa-type nature of KK Tel.
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 June 24, 2002, as VSNET campaign circulation 1322
[Note a large part of detailed information is posted to vsnet-campaign
sub-lists].
VSNET Weekly Campaign Summary
*** Last week news ***
(new targets)
IL Lup (= 4U1543-47) (RA = 15h47m08.6s, Dec = -47d40'09")
J. M. Miller and R. A. Remillard, for the RXTE ASM Team reported
the detection of a new X-ray outburst in the black hole binary,
4U1543-47. The first detections with the RXTE ASM indicated a flux
(2-12 keV) of 0.054 (+/- 0.009) Crab on June 16.683, rapidly
increasing to 0.5 Crab (June 17.122) and 1.65 Crab (June 17.552).
The X-ray spectrum was very soft, implying that the dominant
component was thermal emission from the accretion disk
(vsnet-campaign 1321, vsnet-campaign-xray 144, 145).
T. Kato noticed that the object has an orbital period of 1.123 d
and has the secondary type A2V, which are similar parameters
to those of V4641 Sgr (vsnet-campaign-xray 146). Its outburst
in 1992 rapidly decayed with a short time-scale of 1.6d
(vsnet-campaign-xray 148). B. Monard performed time-series
observations and reported the absence of large flares
(vsnet-campaign-xray 149, 150, 151).
KK Tel (RA = 20h28m38s.46, Dec = -52d18'45".6)
R. Stubbings reported on June 17 that the suspected SU UMa-type
object KK Tel is undergoing a relatively bright outburst
(vsnet-campaign-dn 2582). P. Nelson performed time-series
photometry of KK Tel. The data clearly showed 0.12 mag superhumps.
The object seems to have a rather long (~0.08 d) superhump period.
This observation confirmed the long-suspected SU UMa-type nature of
KK Tel. The light curve on June 18 taken by P. Nelson shows fully
developed superhumps with an amplitude of ~0.35 mag. The light
curve also shows some hints of quasi-periodic oscillations (QPOs)
with time-scales around 10 min. T. Richards performed time-series
observations on June 20. The combined data shows superhumps with a
period of 0.08841(5) d. The light curve taken by R. Santallo
still clearly showed superhumps on June 22. The mean superhump
period using all observations is 0.08804 d, but the observations
are no longer expressed by a single period. The superoutburst
continues (vsnet-campaign-dn 2586, 2590, 2598, 2602, 2605, 2607).
SN 2002dl (RA = 22h20m53s.96, Dec = +33d17'33".7)
T. Puckett and A. Langoussis discovered SN 2002dl (17.7mag)
on an unfiltered CCD frame taken on June 16.35. The host galaxy
of SN 2002dl is UGC 11994, a edge-on spiral galaxy with some
Galactic extinction (A_V = 0.25). The expected maximum for
typical SN Ia is mag about 16.0 (vsnet-campaign-sn 440, 442).
On IAUC 7923, the CfA team reported the spectroscopy of SN 2002dl.
It is of SN Ia with some peculiarity. Si II absorption feature
is strongly shown around 580 nm, which suggests that it would be
a subluminous SN Ia. It was about 2 days before maximum on June
18.43 UT (vsnet-campaign-sn 443).
SN 2002dm (RA = 20h32m07s.30, Dec = -57d35'03".4)
E. Sanders reported her discovery of SN 2002dm on CCD images
obtained on May 4, 10, 13 (V~19.0), and 14. SN 2002dm in IC 5017
had been kept unannounced for 1 month. It was of type Ia about
50 days after maximum on June 16.4 UT. The expected maximum for
typical SN Ia is mag about 16.9. It has somewhat odd color
(although it is deduced from the spectrum), which suggests it may
be abnormal one (vsnet-campaign-sn 440).
SN 2002dn (RA = 21h54m22s.47, Dec = +15d09'42".2)
SN 2002dn was discovered by the KAIT team on CCD images taken
on June 15.5 (mag about 18.6) and 17.5 UT (mag about 18.7).
IC 5145, the host galaxy of SN 2002dn, is a spiral galaxy with
notable Galactic extinction (A_V = 0.33). The expected maximum
for typical SN Ia is mag about 16.9, but it has been revealed to
be probably of type Ic, 1-2 weeks after maximum (vsnet-campaign-sn 440).
SN 2002do (RA = 19h56m12s.88, Dec = +40d26'10".8)
This supernova was discovered by the KAIT team on CCD images
taken on June 17.4 and 18.3 at about 16.3mag. The host galaxy
of SN 2002do is MCG +07-41-1, an elliptical galaxy embedded in
the Milky Way (b = 6.1 deg). The expected maximum for typical
SN Ia (the morphology of the host galaxy suggests this
classification) is mag about 16.4 (vsnet-campaign-sn 442).
1E 2259+586 (RA = 23h01m08s.295, Dec = +58d52'44".45)
V. M. Kaspi et al. reported in GCN that they detected several
short X-ray bursts from the direction of the anomalous X-ray pulsar
1E 2259+586, using the PCA aboard RXTE. The features of bursts
were reminiscent of those seen in soft gamma repeaters
(vsnet-campaign-xray 147).
CI Cyg (RA = 19h50m11s.85, Dec = +35d41'03".1)
A sudden fading was reported on June 18 and 19
(vsnet-campaign-symbio 19).
SN 2002dp (RA = 23h28m30s.12, Dec = +22d25'38".8)
SN 2002dp was discovered in a face-on spiral galaxy NGC 7678
by A. Klotz on CCD images taken on June 18.09 and 19.02 when the
object was 15.1mag. The position is about 31" east and 22"
north of the nucleus of NGC 7678 and superimposed on the
northeastern arm. The expected maximum for typical SN Ia is mag
about 15.1. SN Ib 1997dc also occurred in the same galaxy, whose
maximum was mag about 17.5 (vsnet-campaign-sn 445).
SN 2002dq (RA = 21h19m49s.95, Dec = -08d46'39".8)
SN 2002dq was discovered in an early spiral galaxy NGC 7051
by the KAIT team on CCD images taken on June 18.5 (mag about 17.0)
and 19.4 UT (mag about 17.1). The position is about 20" west
and 19" north of the nucleus of NGC 7051. The expected maximum
for typical SN Ia is mag about 14.8 (vsnet-campaign-sn 445).
alpha Cyg (RA = 20h41m25s.80, Dec = +45d16'49".1)
A possible brightening to 1.0mag was reported on June 21
(vsnet-campaign-sdor 17). It was reported to be at the normal
magnitudes on June 22 (vsnet-campaign-sdor 18).
VW CrB (RA = 16h00m03s.76, Dec = +33d11'14".4)
The SU UMa-type dwarf nova VW CrB is in outburst (14.3mag),
as reported by G. Poyner on June 23. The last recorded
superoutburst occurred in 2001 June (vsnet-campaign-dn 2608).
(continuous targets)
KL Dra (RA = 19h24m38s.14, Dec = +59d41'47".1)
The light curve on June 18 taken by K. Tanabe show that KL Dra
has brightened since the temporary fading on June 16. The
observations suggest that KL Dra has entered the plateau phase
of the current superoutburst. The amplitude of superhumps was
about 0.10mag (vsnet-campaign-dn 2579, 2596, 2597). The outburst
is still ongoing (vsnet-campaign-dn 2606).
EP Car (RA = 10h28m23s.21, Dec = -58d57'58".6)
The outburst still continues (vsnet-campaign-dn 2581, 2583).
V893 Sco (RA = 16h14m45s.26, Dec = -28d39'30".3)
An outburst (12.7mag) was reported by R. Stubbings on June 18
(vsnet-campaign-dn 2588). The outburst again seems to be a short,
normal outburst (vsnet-campaign-dn 2600).
SN 2002di (RA = 16h52m23s.30, Dec = +30d42'40".0)
It is of peculiar (subluminous) SN Ia, roughly 1 week after
maximum on June 17 (the UCB team, IAUC 7920) (vsnet-campaign-sn 441).
SN 2002dk (RA = 18h17m43s.52, Dec = +22d14'53".4)
It is of peculiar SN Ia near maximum on June 17
(vsnet-campaign-sn 441).
SN 2002dg (RA = 14h57m16s.29, Dec = +05d54'00".6)
The Padova team took a spectrum of SN 2002dg on June 15.13,
which reveals that it is type Ib SN, 2-3 weeks after maximum
(vsnet-campaign-sn 441).
Suspect object near NGC 6946
D. Askew reported that the suspected object was invisible on
June 17. The nature of the suspect object is still unknown,
probably until a new positive image or a new outburst detection
becomes available (vsnet-campaign-unknown 87). A. Henden reported
there was no object with limit magnitude of V~22 on June 18
(vsnet-campaign-unknown 88).
V877 Ara (RA = 17h16m58s.80, Dec = -65d32'58".6)
In the light curve taken by T. Richards on June 17, superhumps
were still observed and the secondary humps became evident
(vsnet-campaign-dn 2578, 2580). The mean superhump period is
around 0.0841 d, and the large period change was confirmed
also in the data on June 17 (vsnet-campaign-dn 2584). In the
light curve taken by G. Bolt, superhumps were also detected
and additionally, a temporary fading by 0.15mag were seen
(vsnet-campaign-dn 2587). The object entered a rapid fading
phase since June 18 (vsnet-campaign-dn 2591, 2599).
V359 Cen (RA = 11h58m15s.29, Dec = -41d46'07".9)
The light curve on June 6 by B. Monard shows the final stage
of the superoutburst. The object apparently entered the rapid
fading stage, and was fading at a rate of 0.50 mag/d. Superhumps
were still prominent, without a strong hint of late superhumps.
After combining the data between May 31 and June 6, a mean
superhump period of 0.0809 d has been derived (vsnet-campaign-dn 2601).
QW Ser (RA = 15h26m13s.99, Dec = +08d18'03".8)
The superhumps had slightly decayed on June 7
(vsnet-campaign-dn 2603, 2604).
V4641 Sgr (RA = 18h19m21s.6, Dec = -25d24'25")
The object remains at the calm state (vsnet-campaign-v4641sgr
97, 98).
delta Sco (RA = 16h00m19s.9, Dec = -22d37'17")
S. Otero reported that the object suddenly faded to V=1.89
mag on June 19 (vsnet-campaign-be 191, 192).
V803 Cen (RA = 13h23m44.5s, Dec = -41d44'30".1)
The oscillation phase continues (vsnet-campaign-dn 2585, 2593).
CR Boo (RA = 13h48m55s.42, Dec = +07d57'30".3)
The bright state (~14mag) continues (vsnet-campaign-dn 2594).
V2540 Oph (RA = 17h37m34s.36, Dec = -16d23'18".4)
The slow fading continues. The object is now 10.3-10.4mag
(vsnet-campaign-nova 939).
MV Lyr (RA = 19h07m15s.93, Dec = +44d01'10".7)
The object is still in a faint state (vsnet-campaign-nl 88).
CH Cyg (RA = 19h24m33s.07, Dec = +50d14'29".5)
The gradual fading seems to still continue. The object is
now at 8.9-9.0mag (vsnet-campaign-symbio 18).
*** Future schedule ***
International Symposium: The Universe viewed in gamma-rays
--- Univ. Tokyo Workshop 2002 ---
September 25-28, 2002, Kashiwa, Chiba, Japan
http://icrhp9.icrr.u-tokyo.ac.jp/Symp2002.html
[vsnet-campaign-blazar 264]
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]
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]
[vsnet-campaign-xray 133]
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]
*** General information ***
V877 Ara
Time series observations by T. Richards, see [vsnet-campaign-data 97]
CCD image taken by B. Monard:
http://vsnet.kusastro.kyoto-u.ac.jp/vsnet/DNe/v877ara.html
[vsnet-campaign-dn 2595]
V893 Sco
Eclipse ephemeris, see [vsnet-campaign-dn 2589]
KK Tel
CCD image during outburst provided by P. Nelson:
http://vsnet.kusastro.kyoto-u.ac.jp/vsnet/DNe/kktel.html
[vsnet-campaign-dn 2592]
Time-series observation by T. Richards, see [vsnet-campaign-data 98]
Suspect object near NGC 6946
BV field photometry presented by A. Henden:
http://ftp.nofs.navy.mil/pub/outgoing/aah/sequence/ngc6946.dat
[vsnet-campaign-unknown 88]
SN 2002dp
Charts provided by A. Price:
http://vsnet.aavso.org/charts/catalog/PEG/SN2002DP/
[vsnet-campaign-sn 444]
(This summary can be cited.)
Regards,
Makoto Uemura
Return to Daisaku Nogami
vsnet-adm@kusastro.kyoto-u.ac.jp
VSNET Home Page