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VSNET Weekly Campaign Summary
*** Last week news ***
(new targets)
SN 2003gd (RA = 01h36m42s.65, Dec = +15d44'20".9)
A bright SN II 2003gd was discovered in M74, the same galaxy as
'hypernova' SN 2002ap (vsnet-campaign-sn 636, 637). The discovery
was made on June 12.82 UT at 13.2mag. The first spectrum was taken
on the same night at America, i.e. June 13.46 UT = 0.64 days after
discovery. The IR spectrum shows a series of strong and broad
hydrogen Paschen emission lines, which indicates that it is a type
II SN around maximum (vsnet-campaign-sn 638).
VY Scl (RA = 23h29m00s.4, Dec = -29d46'45")
S. Kerr reported on June 8 that VY Scl was fainter than usual.
The ASAS-3 data also indicated that the object was 0.5-0.7 mag
fainter than usual. This may be a start of a fading episode, which
has not been observed in recent years. In deepest minima, the
object may reach as faint as 18.5 mag (vsnet-campaign-nl 128).
SN 2003fd (RA = 13h41m43s.70, Dec = +40d52'38".5)
SN 2003fd is hosted by UGC 8670, a distant spiral galaxy. The
expected maximum for typical SN Ia is consistent with the discovery
magnitude (17.8-17.4mag) (vsnet-campaign-sn 635).
(continuous targets)
GO Com (RA = 12h56m37s.0, Dec = +26d36'44")
Superhumps persisted with slightly decreasing amplitudes on June
9. The superhumps sometimes showed double-humped profile, which is
most likely interpreted as the appearance of secondary superhump
maxima. On late June 9, the superhump maxima appeared significantly
later than the earlier trend (vsnet-campaign-dn 3766). This trend
was then confirmed, and the object must have undergone a major
period increase. Such a striking period change was very unexpected
for an SU UMa-type dwarf nova in the middle of its superoutburst
plateau. The overall (averaged) period derivative dot(P)/P =
+8x10^(-5). This value is rather unusually large for a system with
this superhump period (vsnet-campaign-dn 3768).
The data on June 10 indicated that the amplitude of the superhumps
has grown again. This variation of the superhump amplitude may be
probably related to the beat phenomenon (vsnet-campaign-dn 3771).
The data on June 11 indicated 0.1 mag rebrightening superimposed on
the general fading trend. This occurrence of a rebrightening is
rather unexpected during the plateau stage of a superoutburst
(vsnet-campaign-dn 3776). The data on June 12 suggested that the
object was fading from the transient brightening. It may be also a
signature of the terminal stage of the superoutburst plateau, or the
beginning of an oscillation phase, as observed in WZ Sge 2001.
There was a sudden period change before the brightening, and the
superhumps now maintains the longer period. The overall (averaged)
superhump period change (Pdot) is positive (vsnet-campaign-dn 3778).
On June 12-13, the most striking feature was that the decrease of
the superhump period. The period change is never monotonous in GO
Com (vsnet-campaign-dn 3780).
The object was reported to fade by 0.5 mag on June 14. This
fading very likely signifies the termination of the superoutburst
plateau (vsnet-campaign-dn 3783, 3784). The rapid fading is ongoing
(vsnet-campaign-dn 3772, 3785, 3786).
V803 Cen (RA = 13h23m44s.5, Dec = -41d44'30".1)
The superoutburst plateau phase lasted at least until the June 8.0
UT. The object entered the rapid fading stage probably at around
June 8.5. The object faded by 1 mag within the next 10 hours.
Althought the fading became slightly slower, the linear fading trend
continued at least until June 9.0 UT. Superhumps were singly peaked
during the early plateau phase, but secondary maxima appeared during
the rapid fading stage. This behavior resembles "late superhumps"
in hydrogen-rich SU UMa-type stars (vsnet-campaign-dn 3767).
On June 9-10, the rapid fading of V803 Cen was halted and probably
reversed around magnitude 15.0. On June 10, T. Richards reported
that the star was at about mag 14.8 and aside from a steady decline
of ~0.1 mag/hr exhibited no variations significantly above the noise
level of ~0.03 mag (vsnet-campaign-dn 3770). After reaching a sharp
peak on June 10.87 UT, the object started fading again (at a slower
rate). During this observation, superhumps were only transiently
active. The overall variation bears some resemblance to
post-superoutburst rebrightening in a hydrogen-rich dwarf novae
(vsnet-campaign-dn 3777). Following the fading on June 11, the
object returned to its maximum (plateau) phase 1 day later, and
subsequently showed a precipitous decline. On the next night, the
object brightened again.
The amplitudes of these oscillations were initially about 1 mag,
and seem to be damping (vsnet-campaign-dn 3773, 3779). The maxima
of the oscillations have been linearly fading at a mean rate of 0.1
mag/d, which is on a smooth extension from the initial superoutburst
plateau. The overall behavior (period and amplitude) of the current
oscillation stage is _strikingly similar_ to the "post-dip" behavior
of WZ Sg observed during its 2001 superoutburst (vsnet-campaign-dn
3782).
rho Cas (RA = 23h54m22s.99, Dec = +57d29'58".7)
No major fading has been observed (vsnet-campaign-rhocas 20).
V729 Sgr (RA = 19h16m49s.15, Dec = -26d14'33".2)
R. Stubbings reported an outburst (13.8mag) on June 10. It is
probably a short outburst (vsnet-campaign-dn 3774).
AH Her (RA = 16h44m09s.99, Dec = +25d15'02".1)
It has possibly entered a new standstill (vsnet-campaign-dn 3775).
MV Lyr (RA = 19h07m15s.93, Dec = +44d01'10".7)
On June 9, quasi-periodic oscillations (QPOs) with a period of 11
min were very clearly detected by T. Krajci. The characteristic
coherence times (coherence lengths) were about 5 cycles, clearly
signifying the QPO nature of this variation (vsnet-campaign-nl 127).
The very bright state continues (vsnet-campaign-nl 129). The most
prominent QPO signal on June 12 was P=9 min. There was a frequency
drift as well as the phase drift in QPOs (vsnet-campaign-nl 130).
EE Cep (RA = 22h09m22s.8, Dec = +55d45'24")
Reported observations showed the object passed the minimum
(vsnet-campaign-ecl 85, 87). Observations by P. A. Dubovsky confirmed
it (vsnet-campaign-ecl 86).
*** Future schedule ***
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]
IAU JD17 "ATOMIC DATA FOR X-RAY ASTRONOMY"
ON JULY 22-23, 2003 at the XXVth IAU GENERAL ASSEMBLY
SYDNEY, AUSTRALIA, JULY 13-26, 2003
for more information:
http://vsnet.astronomy.ohio-state.edu/~pradhan/Iau/iau.html
[vsnet-campaign-xray 227]
"X-ray and Radio Emission of Young Stars"
July 28 - 29, 2003, Rikkyo University, Tokyo, Japan
for more information , please contact to kitamoto@rikkyo.ne.jp
[vsnet-campaign-xray 218]
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 ***
Flares in Mira stars, see [vsnet-campaign-mira 66, 67]
Corrected parameters for delta Velorum, see [vsnet-campaign-deltavel 41]
Eclipes ephemeris, see [vsnet-campaign-dn 3774]
LR Com
Eclipse observed by O. Pejcha, see [vsnet-campaign-ecl 82, 83]
Updated phase plot by D. West:
http://members.aol.com/dwest61506/page39.html
[vsnet-campaign-ecl 84]
V803 Cen
Light curve on June:
http://vsnet.kusastro.kyoto-u.ac.jp/vsnet/DNe/v803cen0306.html
[vsnet-campaign-dn 3781]
(This summary can be cited.)
Regards,
Makoto Uemura
Return to the Powerful Daisaku Nogami
vsnet-adm@kusastro.kyoto-u.ac.jp
