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[vsnet-campaign-news 141] News from VSNET
*** News from VSNET ***
The fifth hypernova, SN 2002bl was discovered.
A new short-period SU UMa-type dwarf nova was discovered.
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 March 11, 2002, as VSNET campaign circulation 1297
[Note a large part of detailed information is posted to vsnet-campaign
sub-lists].
VSNET Weekly Campaign Summary
*** Last week news ***
(new targets)
1RXP J113123+4322.5 (RA = 11h31m22s.426, Dec = +43d22'38".51)
As reported by Pavol A. Dubovsky on March 5, the ROSAT-selected
cataclysmic variable 1RXP J113123+4322.5 is undergoing the
first-ever secure outburst (13.5mag) (vsnet-campaign-dn 2149,
vsnet-campaign-news 140). The outburst was promptly confirmed by
O. Pejcha (vsnet-campaign-dn 2150). Time-series photometry by the
Kyoto team on March 6 revealed the presence of superhumps in the
light curve, which provides evidence for the SU UMa-type nature of
this object (vsnet-campaign-dn 2154). The superhump decreased in
amplitude from 0.3mag to 0.15mag during the superoutburst. The
superhump period was first reported to be 0.068(1)d, and then,
revised with combined data sets to be 0.06495(2) d (reported on
March 8), 0.06497(1) d (March 10), 0.06501(1) (March 11). They
indicate a possible period increase of superhumps during the early
phase of superoutburst (vsnet-campaign-dn 2156, 2158, 2169, 2173,
vsnet-campaign 1296). The ~0.065 period is a relatively short
among SU UMa stars. T. Kato commented that the early appearance
of genuine superhumps looks somewhat unusual for a short-period
system, and that it may be related to ER UMa stars
(vsnet-campaign-dn 2159). D. West and H. Yamaoka independently
performed astrometry. The object makes a pair with a very neighbor
star. Its precise position indicates that the object corresponds
to the northwestern of the pair (vsnet-campaign-dn 2151, 2152,
2155, 2160). The outburst is still ongoing, and it is now about
13.3mag (vsnet-campaign-dn 2153, 2157, 2162, 2167, 2168, 2170).
SN 2002bl (RA = 10h12m17s.28, Dec = +27d51'52".4)
M. Armstrong discovered a SN on March 2.9 at a mag 17.0, which
was revealed to be a hypernova. It is the fifth example of
hypernova, but somewhat more distant. The position is about 5"
west and 9" north of the nucleus of the highly tilted barred-spiral
galaxy UGC 5499. The spectrum of this object was obtained with
Keck-I telescope on Mar. 7. It shows a quite resemblance with
'hypernovae' about 2 weeks after the explosion. The recession
velocity of UGC 5499 is 4753 km/s (NED), which shows good
coincidence with that of a hypernova, SN 1998ey (4839 km/s).
The maximum of this hypernova was mag about 16.8, which is also
in good agreement of the discovery mag of the new object
(vsnet-campaign-sn 364). Radio observations were performed by E.
Berger et al. on March 8. They reported that no radio source was
detected at the position of the SN down to a 2-sigma limit
(vsnet-campaign-sn 372).
SN 2002bo (RA = 10h18m06s.51, Dec = +21d49'41".7)
P. Cacella reported a possible supernova in NGC 3190 in his
image taken on March 9.08 (vsnet-campaign-sn 365, 371). T. Kato
reported no minor planet was present at the position
(vsnet-campaign-sn 366). W. Li promptly confirmed the object
on March 9.4 (vsnet-campaign-sn 367). H. Yamaoka then commented
that the object can reach 12mag without significant extinction
while it nearly superimposed on the dark lane of the host galaxy
(vsnet-campaign-sn 368). W. Li showed that the object is
pretty red and, hence, heavily reddened by much extinction
(vsnet-campaign-sn 369). H. Kawakita et al. revealed that it is
of type Ia at the very early phase (vsnet-campaign-sn 373, 374).
RX J0806.3+1527 (RA = 08h06m22s.9, Dec = 15d27'31".0)
According to astro-ph/0203043, RX J0806.3+1527 is identified
with a variable emission-line object with a pulse period of 321s.
The object is interpreted as a double-degenerate (AM CVn-type)
cataclysmic variable. Since this object is not reddened as in
V407 Vul, further monitoring is strongly encouraged to check
long-term variation (vsnet-campaign 1294).
SAX J1805.5-2031 (RA = 18h05m34s, Dec = -20d30'.8)
According to IAUC 7843, P. Lowes et al. reported the detection
of a new X-ray transient. A search for the optical counterpart
is encouraged (vsnet-campaign-xray 121, 122).
HR Car (RA = 10h22m53s.89, Dec = -59d37'28".0)
P. Williams reported that the SDOR star HR Car appears to be
unsteady between 7.4-7.8mag since 2002 January (vsnet-campaign-sdor
14). B. Monard commented that the object is a tricky star to
estimate, and it is in an active state over two years
(vsnet-campaign-sdor 15).
V844 Her (RA = 16h25m01s.69, Dec = +39d09'25".9)
P. Schmeer reported a possible outburst (13.5mag) of V844 Her
on March 9 (vsnet-campaign-dn 2163). No confirmation was
reported, and the object faded on March 10.
T Ori (RA = 05h35m50s.33, Dec = -05d28'39".1)
Recent observations show that T Ori is now very bright
(9.4-9.8mag) (vsnet-campaign-orion 27).
GU Sgr (RA = 18h24m15s.57, Dec = -24d15'26".1)
GU Sgr is still faint (vsnet-campaign-rcb 18).
(continuous targets)
Nova LMC 2002
(RA = 05h36m46s.4, Dec = -71d35'35".34)
W. Liller took a low resolution spectra, in which H-alpha
emission line was detected. This indicates that the object
is a genuine nova (vsnet-campaign-nova 857). W. Liller and
B. Monard independently measured the position of this nova
(vsnet-campaign-nova 857, 866). The nova is fading gradually,
and now about 11.2mag (vsnet-campaign-nova 858, 859, 860, 863,
864, 867, 868, 871).
SN 2002bj (RA = 05h11m46s.37, Dec = -15d08'10".7)
This SN turned out to be of type II, but shows somewhat peculiar
feature. It does not show a prominent H-alpha emission but a
very blue continuum with shallow features, and it resembles that
of SN II 2001hg or luminous SN IIn 1998S (Gunma team and CfA group).
It was mag about 14.7 on Mar. 3, which suggest that it was quite
luminous (vsnet-campaign-sn 363).
SN 2002bf (RA = 10h15m42s.31, Dec = +55d40'06".7)
This supernova is of type Ia at maximum on Mar 6-7 UT, with
somewhat high expansion velocity (CfA team and UCB-Keck team).
Such high velocity is observed among the luminous SNe Ia
(vsnet-campaign-sn 370).
SN 2002bg (RA = 14h59m39s.23, Dec = +13d12'44".5)
This SN turned out to be a type Ia, 2 weeks after maximum on
Mar. 6.50 UT as shown by the CfA group (vsnet-campaign-sn 363).
SN 2002bh (RA = 09h51m06s.56, Dec = +09d00'05".7)
This SN turned out to be a type-II SN near maximum on Mar. 6
(Asiago team and CfA team). It was mag about 17.4 on Mar. 2
(vsnet-campaign-sn 363).
SN 2002bi (RA = 13h32m54s.45, Dec = +09d31'18".0)
It turned out to be of type Ia, but roughly 1 month past
maximum on Mar. 7, as revealed by UCB - Keck team
(vsnet-campaign-sn 370).
HadV98 (RA = 17h23m14s.5, Dec = -22d52'05")
The object is now faint (V=12.68 on March 9, by S. Kiyota)
(vsnet-campaign-rcb 19, vsnet-campaign-unknown 67).
AX Per (RA = 01h36m22s.72, Dec = +54d15'02".7)
The object is still in an eclipse. Observations of 12.4-12.6mag
were reported on March 9-10 (vsnet-campaign-symbio 11).
IM Nor (RA = 15h39m26s.47, Dec = -52d19'18".2)
The object was further fading (vsnet-campaign-nova 861).
A possible brightening was reported on March 4
(vsnet-campaign-nova 865). The object is now at about 10.6-10.7mag
(vsnet-campaign-nova 873).
GK Per (RA = 03h31m12s.50, Dec = +43d54'17".8)
The object further brightened on March 4 (vsnet-campaign-gkper
33, 34), and the rising seems to be gradual (vsnet-campaign-gkper
35, 36, 39, 42, 43, 44, 46, 47, 48, 50). The X-ray observations
are planned with RXTE, XMM-Newton, and Chandra (vsnet-campaign
1295, vsnet-campaign-gkper 41). The Kyoto team performed
time-series photometry on March 8 and 9. The resultant light
curve shows strong modulations with multiple frequencies of 518s
and 4510s (vsnet-campaign-gkper 49).
chi Cyg (RA = 19h50m33s.9, Dec = +32d54'50")
The object is now fading. 4.5-4.8mag were reported during
the last week. (vsnet-campaign-mira 20).
SN 2002bk
This supernova turned out to be a type Ia, about 5 weeks
past maximum on March 7 (vsnet-campaign-sn 370).
HL CMa (RA = 06h45m17s.0, Dec = -16d51'35")
The object gradually faded from an unusual, long outburst.
It is now 11.8-12.5mag (vsnet-campaign-dn 2166).
RR Tau (RA = 05h39m30s.53, Dec = +26d22'26".3)
The object is possibly fading again. Recent observations show
it is about 11.5mag (vsnet-campaign-orion 26).
SN 2002ap (RA = 01h36m23s.85, Dec = +15d45'13".0)
This supernova is now fading gradually. The current magnitude
is about 14.2mag (vsnet-campaign-sn2002ap 189, 190, 191, 192,
193, 194).
V803 Cen (RA = 13h23m44s.5, Dec = -41d44'30".1)
An outburst of 13.8mag was reported on March 4 by R. Stubbings
(vsnet-campaign-dn 2148), but the object faded on March 5 and
remains at a faint state (vsnet-campaign-dn 2164).
V2540 Oph (RA = 17h37m34s.36 Dec = -16d23'18".4)
A possible brightening of 9.9mag was reported on March 4
by B. Tregaskis (vsnet-campaign-nova 862), and it was confirmed
on March 6 at 9.5mag by A. Pearce (vsnet-campaign-nova 869).
The object further brightened to 8.9mag on March 7
(vsnet-campaign-nova 870). It remains at the bright state
(vsnet-campaign-nova 872, 874).
BZ Cam (RA = 06h29m34s.49, Dec = +71d04'39".5)
The object is still relatively active (vsnet-campaign-nl 73).
MV Lyr (RA = 19h07m15s.93, Dec = +44d01'10".7)
Recent observations show that MV Lyr is possibly slightly
fading (vsnet-campaign-nl 74).
SN 2002an (RA = 08h22m47s.76, Dec = +24d17'41".7)
The object is now gradually fading. The current magnitude is
about 16.6mag (vsnet-campaign-sn 362).
V838 Mon (RA = 07h04m04s.816, Dec = -03d50'50".94)
In the spectrum on March 3, C. Buil reported that the H-alpha
emission component was continuously weakening (vsnet-campaign-v838mon
256). M. Fujii took a new spectrum, which show that Na I
absorption has become weaker (vsnet-campaign-v838mon 268).
The relatively rapid brightening continued until about March 4,
and then, the rising rate appears to be gradual
(vsnet-campaign-v838mon 248, 249, 250, 251, 252, 253, 254, 255,
257, 260, 266). C. Sherrod reported that the object was relatively
calm at about 7.7mag on March 5 (vsnet-campaign-v838mon 258).
And then, the object again started brightening
(vsnet-campaign-v838mon 259, 261, 262, 263, 264, 265, 267, 269,
270, 271, 272, 273). It is now very bright at about 7.1mag
(vsnet-campaign-v838mon 274).
V1333 Aql (RA = 19h11m16s.09, Dec = +00d35'06".0)
S. Ilovaisky reported that the object is bright also in optical
range. It was Rc=16.5 on March 4 (vsnet-campaign-xray 120).
V854 Cen (RA = 14h34m49s.8, Dec = -39d33'18")
The object stopped rising and remains at 8mag
(vsnet-campaign-rcb 17).
DW Cnc (RA = 07h58m56s.80, Dec = +16d16'48".2)
The object is reported to be brighter (vsnet-campaign-nl 75,
vsnet-campaign-dn 2172).
UX Ori (RA = 05h04m30s.39, Dec = -03d47'18".3)
The object is still very faint at 11mag
(vsnet-campaign-orion 25, 28).
AT Cnc (RA = 08h28m36s.92, Dec = +25d20'02".6)
The object started fading from the standstill
(vsnet-campaign-dn 2165).
CR Boo (RA = 13h48m55s.42, Dec = +07d57'30".3)
M. Uemura reported a new outburst of CR Boo on March 8
(vsnet-campaign-dn 2161). He also detected superhumps, which
provide evidence for the superoutburst nature of the current
outburst. Since the last outburst occurred two weeks ago, it was
revealed that the short supercycle sill continues in this object
(vsnet-campaign-dn 2174). The superoutburst is still ongoing
(vsnet-campaign-dn 2171).
OJ287 (RA = 08h51m57s, Dec = 20d17'59")
The object is still active (vsnet-campaign-blazar 254).
*** Future schedule ***
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]
International workshop
"XEUS - studying the evolution of the hot universe"
March 11-13, 2002 ; MPE Garching, Germany
for more information, see
http://wave.xray.mpe.mpg.de/conferences/xeus-workshop
[vsnet-campaign-xray 98]
[vsnet-campaign-xray 104]
*** General information ***
1RXP J113123+4322.5
Image superimposed by the GSC-2.2 star marks provided by H. Yamaoka:
http://ftp.kusastro.kyoto-u.ac.jp/pub/vsnet/DNe/J1131/
[vsnet-campaign-dn 2160]
SN 2002ap
Light curve provided by L. Cook:
http://vsnet.geocities.com/lcoo/sn2002ap.gif
[vsnet-campaign-sn2002ap 188]
SN 2002ao
Discovery image taken by P. Cacella:
http://users.linkexpress.com.br/cacella/index_i.htm
[vsnet-campaign-sn 365]
GK Per
Comparison stars for GK Per, see [vsnet-campaign-gkper 37, 40]
Sequence presented by B. Skiff, see the links at:
http://vsnet.kusastro.kyoto-u.ac.jp/vsnet/Novae/gkper.html
[vsnet-campaign-gkper 38]
New charts by AAVSO:
http://vsnet.aavso.org/charts/PER/GK_PER/
Special edition of CCD Views (AAVSO):
http://vsnet.aavso.org/ccdviews/ccdviewsspecial-gkper.shtml
[vsnet-campaign-gkper 45]
V838 Mon
Low resolution spectrum on March 3 taken by C. Buil:
http://vsnet.astrosurf.com/buil/us/nmon/nmon.htm
[vsnet-campaign-v838mon 256]
Image taken by C. Sherrod:
http://vsnet.arksky.org/asoimg/v838mon0308.JPG
[vsnet-campaign-v838mon 264]
Spectrum taken by M. Fujii:
http://vsnet1.harenet.ne.jp/~aikow/v838_0309.gif
[vsnet-campaign-v838mon 268]
(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
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