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[vsnet-campaign-news 111] News from VSNET 81
*** News from VSNET ***
Superhumps were detected during the outburst of DM Dra.
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 November 19, 2001, as VSNET campaign circulation 1229
[Note a large part of detailed information is posted to vsnet-campaign
sub-lists].
VSNET Weekly Campaign Summary
*** Last week news ***
(new targets)
DM Dra (RA = 15h34m12s.13, Dec = +59d48'31".9)
As reported by T. Kinnunen on November 14, an outburst of DM Dra
at 14.6mag was detected (vsnet-campaign 1227). T. Vanmunster
discovered superhumps with an amplitude of 0.36 mag on Novemer
14/15 and revealed its SU UMa-type nature (vsnet-campaign-dn 1890).
He furthermore reported their period of 0.0734 +/- 0.0030 d which
substantially differs from that previously reported
(vsnet-campaign-dn 1891). The Kyoto team also detected superhumps
and reported candidates of the period of 0.0733 d or 0.0750 d
(vsnet-campaign-dn 1910). T. Kato reported that the observation at
Kyoto in 2000 October during a possible superoutburst showed the
amplitude of superhumps were less than 0.1mag. This suggests that
the amplitude of superhumps can quickly decay in this system
(vsnet-campaign 1228). The superoutburst is still ongoing
(vsnet-campaign-dn 1894, 1901, 1906).
SN 2001fz (RA = 06h44m50s.26, Dec = -27d37'12".7)
IAUC 7753 informed the discovery of a SN in the neighbouring galaxy
NGC 2280 in Canis Major. The Beijing Astronomical Observatiory team
discovered SN 2001fz on Nov. 15.8 (17.4 mag) and 16.7 (17.0 mag) at
the nearby galaxy NGC 2280. The position is about 16" east and 66"
north of the nucleus of the inclined spiral galaxy NGC 2280.
It locates the outermost part of the arm region. The host galaxy is
the late type, so there are many H II regions on the disk.
The expected maximum for typical SN Ia in this galaxy is mag about
14.0 (included the Galactic extinction), and mag about 16 for typical
SN II (vsnet-campaign-sn 277, 278).
XRF011030 (RA = 20h43m32s.5, Dec = +77d17'17".4)
Harrison et al. obtained a 47 ksec Chandra observation of the
field containing the BeppoSAX X-ray transient XRF 011030 (GCN 1118),
centered on the radio transient reported by Taylor et al. (GCN 1136).
The X-ray spectrum over 0.2-5 keV is consistent with a power law of
photon index ~1.45. They derived an unabsorbed flux of 2.4e-13 erg
cm^-2 s^-1. (vsnet-campaign-xray 97).
TK5 (RA = 19h17m26s.5, Dec = +37d10'41")
P. A. Dubovsky detected an outburst (14.2mag) of this object
on November 17. It is the brightest outburst reported to VSNET
(vsnet-campaign-dn 1913).
(continuous targets)
EY Cyg (RA = 19h54m36s.77, Dec = +32d21'54".7)
The long rare outburst is still ongoing. The object is now about
12.5mag (vsnet-campaign-dn 1896, 1900, 1907, 1914).
SN 2001fv (RA = 11h04m01s.66, Dec = +28d01'55".7)
The CfA team revealed that SN 2001fv is of type Ia few weeks
after maximum and in the plateau phase (vsnet-campaign-sn 276).
CC Cnc (RA = 08h36m19s.17, Dec = +21d21'05".4)
The superhump detection by the Kyoto team confirmed the current
outburst is a superoutburst (vsnet-campaign-dn 1889).
The superoutburst is still ongoing (vsnet-campaign-dn 1886, 1887,
1895, 1902, 1905). Using the 6 nights observations at Kyoto,
T. Kato reported the superhump period of 0.07571(4) d which is
3.0% longer than the orbital period. Modulations with a period
of 2-3 d is also superimposed on the light curve, suggesting the
presence of a beat phenomenon (vsnet-campaign-dn 1911). In the
data observed by J. Pietz, T. Kato noticed a possible low-amplitude
QPO feature (vsnet-campaign-dn 1915).
AK Cnc (RA = 08h55m21s.21, Dec = +11d18'14".7)
The object showed a possible rapid fading on November 14
(vsnet-campaign-dn 1897), and then again brightened. The early
brightening may be precursor of the current possible superoutburst
(vsnet-campaign-dn 1904).
1RXS J232953.9+062814 (RA = 23h29m54s.30, Dec = +06d28'10".9)
The object is now very gradually fading (vsnet-campaign-dn 1884,
1885, 1892, 1893). A. Oksanen reported the object has faded to
16.6mag on November 17 (vsnet-campaign-dn 1903). The light curve
showed superhumps and sometimes double humps (vsnet-campaign-dn 1885).
Using the data on November 13 and 14, the period analysis yielded
0.04591(8) d, which is 0.8% shorter than the superhump period.
The emergence of a significantly different period is highly
suggestive of the (co-)existence of orbital modulations
(vsnet-campaign-dn 1888). The superhump signal became weak on
November 16, and the overall feature resembles the quiescent light
curve. The period analysis of the data on November 14 and 16
yielded the period of 0.04522 d, which means the superhump excess
is about 2% (vsnet-campaign-dn 1899).
U Gem (RA = 07h55m05s.55, Dec = +22d00'09".2)
The object is going back to quiescence (vsnet-campaign-dn 1908).
WZ Sge (RA = 20h07m36s.53, Dec = +17d42'15".3)
The gradual fading still continues (vsnet-campaign-dn 1909).
SN 2001fe (RA = 09h37m57s.10, Dec = +25d29'41".3)
The CfA team revealed that SN 2001fe is of type Ia, near maximum
on Nov. 14 (vsnet-campaign-sn 276).
SN 2001ff (RA = 08h57m00s.97, Dec = +13d11'59".5)
The CfA team revealed that SN 2001ff is of type II past maximum
(vsnet-campaign-sn 276).
IX Dra (RA = 18h12m32s.2, Dec = +67d04'41")
As reported by Pavol A. Dubovsky on November 17, the ER UMa-type
dwarf nova, IX Dra is undergoing a bright outburst (14.6mag),
which may be a superoutburst (vsnet-campaign-dn 1912).
*** Future schedule ***
WZ Sge campaign
D. Steeghs wrote:
"Several of us are organizing a campaign on the current outburst
of WZ Sge, using a large variety of ground based facilities as well as
space observatories. A web-page has been setup listing the scheduled
observations so far which we intend to keep up to date at:
http://vsnet.astro.soton.ac.uk/~ds/wzsge.html
"
For more information, see [vsnet-campaign 1039]
Supernova campaign: A great opportunity for amateurs by M. Schwartz.
For more detailed information, see [vsnet-campaign-sn 233]
announce on the HST observations, see [vsnet-campaign-sn 240, 246]
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]
Blazar meeting at Tuorla: June 17-21, 2002
for more information, see http://vsnet.astro.utu.fi/blazar02
[vsnet-campaign-blazar 232]
*** General information ***
Spectra of recent supernovae:
http://cfa-www.harvard.edu/cfa/oir/Research/supernova/RecentSN.html
[vsnet-campaign-sn 276]
DM Dra
Observations by T. Vanmunster:
http://vsnet.lunarpages.com/cbabelgium
[vsnet-campaign-dn 1898]
(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
VSNET Home Page