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*** News from VSNET ***
PU CMa experienced a bright, short outburst.
R CrB started fading.
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 February 17, 2003, as VSNET campaign
circulation 1370
[Note a large part of detailed information is posted to vsnet-campaign
sub-lists].
VSNET Weekly Campaign Summary
*** Last week news ***
(new targets)
PU CMa (RA = 06h40m47s.67, Dec = -24d23'14".6)
As reported by R. Stubbings in [vsnet-outburst 5213] on February
13, the short-period (candidate) SU UMa-type dwarf nova PU CMa
experienced a bright outburst (11.2mag). PU CMa, with its outburst
properties strongly resembling a normal SU UMa-type dwarf nova may
be the first object filling the gap between the extreme WZ Sge-type
and ER UMa-type systems (vsnet-campaign-dn 3434, 3435). The object
was still bright at about 11.7mag on February 14 (vsnet-campaign-dn
3437). Based on the data mainly on Feb. 14, T. Kato reported the
detection of small-amplitude (0.03 mag) variations. The best period
was around 0.053 d, which is shorter than the orbital period. It
may have been possible some sort of "negative superhumps"
transiently appeared during this stage (vsnet-campaign-dn 3441). On
February 15, the object started rapid fading (vsnet-campaign-dn
3443, 3444). The light curve on February 16 was dominated by
large-amplitude variations (~0.3 mag). The phase-folded light curve
shows a single-peaked profile (mean amplitude 0.3 mag), which is
reminiscent of superhumps. There also existed variations with
shorter time scales, but they looked more aperiodic or
quasi-periodic (vsnet-campaign-dn 3445).
SN 2003am (RA = 13h20m43s.57, Dec = -22d02'53".5)
SN 2003am is hosted by ESO 576-G40, an edge-on spiral galaxy with
notable disturbance. It had produced SN Ia 1997br, which was
intrinsically bright but somewhat reddened and whose maximum was R
about 13.7 (vsnet-campaign-sn 557).
SN 2003sn (RA = 13h27m53s.55, Dec = +28d30'29".2)
SN 2003an is hosted by MCG +05-32-22, a probable spiral galaxy.
The discovery magnitude is consistent with the expected maximum
for SN Ia (vsnet-campaign-sn 557).
Possible Nova in M81 (RA = 09h55m48s.59, Dec = +69d03'04".3)
The new object is located at about 83"E , 51"S of the nucleus of
M81. The absolute magnitude of this object is estimated as about
-10, which is extremely bright for a classical nova
(vsnet-campaign-sn 557). T. Kato commented that if this is indeed a
nova, it may fade rapidly, as suggested by the absolute magnitude
(vsnet-campaign-nova 1151).
X1901+031 (RA = 19h03m33s, Dec = +03d12'.4)
According to IAUC No. 8070, Galloway et al. reports a new outburst
of the X-ray transient X1901+031. The object is suggested to be a
Be-type high-mass X-ray binary (vsnet-campaign-xray 191).
SN 2003ao (RA = 09h45m48s.46, Dec = -14d22'14".0)
SN 2003ao is hosted by NGC 2993, a disturbed spiral galaxy making
an interacting pair Arp 245 with NGC 2992. The SN is superimposed
on the central bulge region. The expected maximum for typical SN
Ia is mag about 14.4, but the reported magnitudes (17.3: mag)
suggest it is probably a core-collapse event in its plateau phase
(vsnet-campaign-sn 559).
SN 2003ap (RA = 09h50m52s.83, Dec = -21d51'10".1)
SN 2003ap is hosted by 2MASXi J0950528-215109, a very small
galaxy. It lies about 6'.6 from ESO 566-G18, which produced SN II
2001af. The CTIO spectrum of SN 2003ap taken on Feb. 11.20 UT
revealed that it was type Ia SN near maximum, superimposed on an
active-galaxy spectrum. The recession velocity of the host galaxy
is coincident with that of ESO 566-G18, so the reported magnitude
(16.7C mag) is consistent to the expected maximum for typical SN Ia,
on the other hand SN 2001af seems to had been quite luminous as a SN
II (vsnet-campaign-sn 560).
Var73 Dra (RA = 20h23m38s.193, Dec = +64h36m26s.91)
The Kyoto observations on February 12 confirmed that Var73 Dra is
undergoing a new superoutburst. This observation confirms that
suggested claim of a very short supercycle (vsnet-campaign-dn 3430).
SN 2003aq (RA = 14h10m07s.24, Dec = +17d37'05".3)
SN 2003aq is hosted by NGC 5490C = Arp 79, a face-on barred spiral
galaxy. The SN is superimposed on the northeastern arm. NGC
5490C belongs to a group (or cluster) of galaxies led by NGC 5490
(elliptical), which had produced peculiarly less luminous SN Ia
1997cn. The expected maximum for typical SN Ia in this group is
mag about 16.1, then SN 2003aq (18.5C, 18.0C mag) seems to be a
gravitational-collapse event (vsnet-campaign-sn 561).
SN 2003ar (RA = 16h02m08s.11, Dec = +70d24'55".5)
SN 2003ar is hosted by MCG +12-15-47, which is probably identified
with poorly coordinated NGC 6071, an early-type galaxy. The
expected maximum for typical SN Ia is mag about 16.7
(vsnet-campaign-sn 561).
SN 2003as (RA = 05h28m45s.81, Dec = +49d52'59".1)
SN 2003as is hosted by MCG +08-10-7, a spiral galaxy near the
Galactic plane. The expected maximum for typical SN Ia is mag
about 17.6 in R, but unfiltered CCD observation (16.8C mag) would
make a brighter magnitude because of the infrared leak
(vsnet-campaign-sn 561, 562).
beta CMi (RA = 07h27m09s.24, Dec = +08d17'23".4)
A possible fading (3.3mag) was reported on February 16
(vsnet-campaign-be 212). T. Gandet announced that they will take
Coude spectra of Beta CMi later this week and calls for observations
(vsnet-campaign-be 213).
MV Lyr (RA = 19h07m15s.93, Dec = +44d01'10".7)
G. Comello reported that the VY Scl-type variable MV Lyr is
apparently in outburst at 12.5 mag on Feb. 14 and 12.8mag on Feb. 16
(vsnet-campaign-nl 107).
SN 2003at (RA = 16h38m47s.81, Dec = +66d01'23".7)
SN 2003at is hosted by MCG +11-20-23, a dim spiral? galaxy. It
seems to be a foreground galaxy of the cluster Abell 2218. There is
a dim (mag about 18) foreground star about 21" due south of the
nucleus of MCG +11-20-23 (vsnet-campaign-sn 563).
(continuous targets)
SN 2003af (RA = 11h10m21s.69, Dec = +23d24'50".9)
The CfA team has taken spectra, and revealed that it was type Ia
supernova, near maximum on Feb. 9 (vsnet-campaign-sn 558).
SN 2003ag (RA = 11h26m01s.82, Dec = +01d59'02".8)
It is also a type Ia supernova, near maximum on Feb. 9
(vsnet-campaign-sn 558).
SN 2003ai (RA = 13h00m58s.68, Dec = +39d51'24".5)
It was type Ia supernova about a week before the maximum on
Feb. 10. It seems to be possibly a luminous event, judged from the
strength of Si II 635 nm absorption (vsnet-campaign-sn 558).
BC UMa (RA = 11h52m15s.88, Dec = +49d14'42".0)
Using the combined data set reported by the VSNET collaboration
team, T. Kato reported that after the initial period of the period
increase, the period suddenly started shortening. The overall
period behavior somehow looks like that of AL Com in 1995, but the
amplitude of the variation is larger (vsnet-campaign-dn 3431).
The object started rapid fading from the superoutburst on February
13 (vsnet-campaign-dn 3427, 3432, 3436, 3438, 3439, 3442).
Time-series observations on Feb. 13-14 revealed the presence of
humps. There was a main hump with an amplitude of 0.3 mag and a
smaller hump at phase 0.5, suggesting that the profile is a
combination of superhumps and late superhumps (vsnet-campaign-dn
3440).
ST Cha (RA = 10h47m31s.3, Dec = -79d27'17")
The object is still in a standstill (vsnet-campaign-dn 3428).
IGR J16318-4848 (RA = 16h31m52s, Dec = -48d48'.5)
According to IAUC No. 8070, Murakami et al. report that a highly
absorbed X-ray source is present in ASCA archival data close to the
reported position of IGR J16318-4848 (vsnet-campaign-xray 190). The
TOO X-ray observation with XMM-Newton on February 10 revealed a
bright and absorbed X-ray source. This source is likely the soft
X-ray counterpart of the hard X-ray source (vsnet-campaign-xray
193, 194).
R CrB (RA = 15h48m34s.40, Dec = +28d09'23".7)
The object is now fading. It now probably entered 7th mag
(vsnet-campaign-rcb 94, 95, 96, 97, 98).
GZ Cnc (RA = 09h15m51s.70, Dec = +09d00'50".2)
A new outburst was reported on February 11. It was still in a
faint state on February 10 (vsnet-campaign-dn 3429). During this
outburst, time-series observations showed a rapid fading trend and
the presence of oscillations with a typical time-scale of 30 min.
However, in contrast to Jan. 29 observation, there was no clear hint
of short-term (minutes) spike-like variations (vsnet-campaign-dn
3433).
MisV1147 (RA = 22h54m03s.78, Dec = +58d54'02".1)
The object has recovered from the last fading
(vsnet-campaign-unknown 186).
eta Gem (RA = 06h14m52s.87, Dec = +22d30'24".5)
T. Markham also reported that the next Eta Gem eclipse is
predicted for Jly-Aug 2004 (vsnet-campaign-ecl 61, 62).
V4744 Sgr (RA = 17h47m21s.724, Dec = -23d28'22".79)
The fading seems to be even deeper than the previously mentioned
magnitude (vsnet-campaign-nova 1153, 1154).
*** 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, 24,
25, 26]
[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 ***
BC UMa
Profiles of superhumps during the rapid decline phase:
http://vsnet.kusastro.kyoto-u.ac.jp/pub/vsnet/DNe/BC_UMa/bclate.gif
[vsnet-campaign-dn 3440]
eta Gem
Observations by P. Ferenc, see [vsnet-campaign-ecl 59]
IGR J16318-4848
CCD image by B. Monard:
http://vsnet.kusastro.kyoto-u.ac.jp/pub/vsnet/Xray/IGRJ16318-4848/monard2.gif
http://vsnet.kusastro.kyoto-u.ac.jp/pub/vsnet/Xray/IGRJ16318-4848/monard2.fits
[vsnet-campaign-xray 192]
XMM News:
http://xmm.vilspa.esa.es/external/xmm_news/items/IGR/index.shtml
[vsnet-campaign-xray 193, 194]
S. Kiyota's recent observations of novae (V2540 Oph, V4742 Sgr,
V4743 Sgr, V4744 Sgr), see [vsnet-campaign-nova 1152]
V2540 Oph and GSC 6248:1255
Visual chart provided by D. West:
http://hometown.aol.com/dwest61506/page64.html
[vsnet-campaign-unknown 187]
GSC 1448:2869 (TmZ V772)
Visual chart provided by D. West:
http://hometown.aol.com/dwest61506/page65.html
[vsnet-campaign-unknown 188]
V1413 Aql
Comments on the discovery of the eclipse phenomenon in this
object by T. Kato, see [vsnet-campaign-ecl 63],
[vsnet-campaign-symbio 45]
UX UMa
Time-series observation by H. Maehara, see [vsnet-campaign-data
108]
Discussion about "CCD-V Vs visual observations"
[vsnet-campaign-ccd-discussion 29, 30, 31, 32, 33, 34, 35, 36, 37,
38, 39, 40, 41]
(This summary can be cited.)
Regards,
Makoto Uemura
Return to the Powerful Daisaku Nogami
vsnet-adm@kusastro.kyoto-u.ac.jp
