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[vsnet-campaign-news 110] News from VSNET 80
*** News from VSNET ***
The detection of 66-min superhumps strongly indicates that
1RXS J232953.9+062814 is a dwarf nova below the "period minimum"
of cataclysmic variables.
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 12, 2001, as VSNET campaign circulation 1226
[Note a large part of detailed information is posted to vsnet-campaign
sub-lists].
VSNET Weekly Campaign Summary
*** Last week news ***
(new targets)
SN 2001fh (RA = 21h20m42s.50, Dec = +44d23'53".2)
IAUC 7744 tells the discovery of SN 2001fh at r=17.87 by the
KAIT team on November 3.2 and 5.2. H. Yamaoka reported that
PGC 66592, the host galaxy of SN 2001fh, is a spiral galaxy
enbedded on the Galactic plane. The expected maximum of SN Ia
on the distance of this galaxy is mag about 15.2, but there is
a large obsecuration by the interstellar medium in our Galaxy
(vsnet-campaign-sn 272). The Asiago team and the CfA team has
taken the spectrum around Nov. 7.0. It was revealed that it was
of type Ia slightly before maximum (vsnet-campaign-sn 274).
SN 2001fu (RA = 08h52m16s.58, Dec = -17d44'29".8)
The discovery of SN 2001fu was made on Nov. 5.5 at mag about 15.1.
The position is about 25" west and 11" north of the nucleus of the
spiral galaxy MCG -03-23-11 (vsnet-campaign-sn 273). The CfA team
also observed SN 2001fu and revealed that it was of type Ia a few
weeks past maximum. They measured the recession velocity of the
host galaxy as 1730 +/- 30 km/s. The expected maximum for typical
unreddened SN Ia in this galaxy is mag about 13.5, which occured
probably on some date in 2001 September or October
(vsnet-campaign-sn 274).
4U 1608-522 = QX Nor (RA = 16h12m42s.6, Dec = -52d25'21")
According to ATEL #77 (Rutledge), this X-ray transient (neutron
star transient) is in outburst, based on RXTE/ASM observations
(vsnet-campaign-xray 95).
EY Cyg (RA = 19h54m36s.77, Dec = +32d21'54".7)
The object is now in a rare outburst as reported by H. McGee
on November 8 (vsnet-campaign-dn 1862). The outburst is still
ongoing, and the current magnitude is about 12.6mag
(vsnet-campaign-dn 1867, 1881).
SAX J2043.6+7717 (RA = 20h43m42s.48, Dec = +77d17'34".8)
Heise et al. reported in GCN 1138 that this X-ray rich and weak
gamma-ray transient is a totally new class of transient phenomena.
X-ray emissions during its eruption is non-thermal and the ourburst
duration is less than a few thousand seconds. The optical and
infrared counterpart of this object have not been significantly
detected (vsnet-campaign-xray 96).
SN 2001fv (RA = 11h04m01s.66, Dec = +28d01'55".7)
IAUC 7750 tells the discovery of SN 2001fv at 16.8mag by
M. Armstrong on November 3. H. Yamaoka reported that NGC 3512,
the host face-on spiral galaxy of SN 2001fv, has nearly the same
distance as the Virgo Cluster. The expected maximum for typical
SN Ia is mag about 13. The maximum, however, was possibly missed
during the solar conjunction (vsnet-campaign-sn 275).
CC Cnc (RA = 08h36m19s.17, Dec = +21d21'05".4)
As reported by M. Simonsen on November 10, the SU UMa-type
dwarf nova CC Cnc is undergoing a bright outburst (13.2mag).
The present outburst may be a superoutburst. Since the superhump
period has not been precisely determined yet, we would encourage
time-series observations to precisely determine the superhump period,
superhump excess and the period change (vsnet-campaign 1221).
AK Cnc (RA = 08h55m21s.21, Dec = +11d18'14".7)
As reported by M. Simonsen on November 10, the SU UMa-type
dwarf nova AK Cnc is undergoing an outburst (13.2mag). The
brightness may suggest a superoutburst, though there was already
one in this April (vsnet-campaign 1222). The outburst is still
ongoing (vsnet-campaign-dn 1872).
(continuous targets)
CI UMa (RA = 10h18m13s.01, Dec = +71d55'42".8)
The analysis of the Kyoto Oct. 31 - Nov. 4 data has yielded a
superhump period of 0.0628 d. The amplitude of superhumps has
decreased during this interval (vsnet-campaign-dn 1846).
1RXS J232953.9+062814 (RA = 23h29m54s.30, Dec = +06d28'10".9)
The short periodicity of superhumps were confirmed by T. Vanmunster
on November 5/6. This object is now a new SU UMa star below the
period minimum (vsnet-campaign 1211, 1212, 1213).
The observational campaign has become extensive. The VSNET
collaboration team has obtained time-series observations from
the Kyoto team (vsnet-campaign-dn 1853, 1875), D. Starkey
(vsnet-campaign-dn 1843), J. Pietz (vsnet-campaign-dn 1847),
S. Kiyota (vsnet-campaign-dn 1850, 1858), T. Vanmunster
(vsnet-campaign-dn 1863), K. Torii (vsnet-campaign 1220), T. Tanabe
and K. Matsumoto (vsnet-campaign 1220), T. Krajci (vsnet-campaign 1224),
and A. Giambersio.
According to Jingyao et al (1998), The outburst spectrum resembles
that of an A-star. The quiescent spectrum was dominated by Balmer
and He I emission lines, indicating that the object is not
hydrogen-poor (vsnet-campaign-dn 1844). Time-resolved spectroscopy
during quiescence had been performed by Zharikov and Tovmassian.
They reported that a possible orbital period of 0.0446 d, indicating
the superhump excess of 3.7% (vsnet-campaign-dn 1852). During this
outburst, spectroscopy and infrared photometry were taken by Dr.
David Barrado y Navascues at Calar Alto (vsnet-campaign-dn 1860).
The Gunma team also performed spectroscopy and reported a spectra
with weak absorption lines of H-beta, H-gamma and H-delta, and the
H-alpha emission (vsnet-campaign-dn 1861).
B. Skiff reported a proper motion of this object to be 0".049/yer
using USNO-A2.0 and GSC-2.2 catalogues (vsnet-campaign-dn 1851).
H. Yamaoka also reported to be 0".05 - 0".06 /yr using the Kyoto
images (vsnet-campaign-dn 1857).
The superhump period was calculated to be 0.046330(10) d
(vsnet-campaign-dn 1845, 1847, 1854). T. Kato reported a period
increase of superhumps. The mean period derivative is dot{P}/P =
6x10^(-5) (vsnet-campaign-dn 1859). The amplitude of humps became
smaller with time, and on November 7, the object rapidly faded
(vsnet-campaign 1218, 1219). The fading rate became gradual
on November 9 (vsnet-campaign-dn 1864). On late November 9, the
object experienced a rebrightening reaching 13.0mag
(vsnet-campaign 1220). During this rebrightening, T. Vanmunster
detected superhumps as in the plateau phase (vsnet-campaign 1223,
1225). It has faded with the duration of about 1 day
(vsnet-campaign-dn 1876, 1877, 1878). T. Kato wrote in
[vsnet-campaign-dn 1879] that the persistence of superhumps is
similar to ER UMa stars (vsnet-campaign-dn 1879). The D. Starkey's
data on the fading phase show a slightly shorter periodicity of
0.04608(4) d, indicating a possible orbital modulations
(vsnet-campaign-dn 1880).
T Leo (RA = 11h38m26s.96, Dec = +03d22'08".1)
The superoutburst seems to finish around November 6
(vsnet-campaign-dn 1855, 1871).
AM Cas (RA = 02h26m23s.40, Dec = +71d18'32".3)
The outburst is still ongoing. The current magnitude is about
12.8mag (vsnet-campaign-dn 1868).
U Gem (RA = 07h55m05s.55, Dec = +22d00'09".2)
The outburst is fading now (vsnet-campaign-dn 1856, 1869).
SDSSp J173008.38+624754.7 (RA = 17h30m08s.38, Dec = +62d47'54".7)
The observation on November 6 by the Kyoto team showed the
object brightened again. This brightening may be a
post-superoutburst rebrightening, or may represent the start of
the phase of recurring normal outbursts. In the latter case,
the recurrence time is expected to be short as inferred by the
observation (vsnet-campaign-dn 1849).
Nova Cen 2001 (RA = 13h55m41s.27, Dec = -64d15'57".9)
The object was further fading under 12.5mag
(vsnet-campaign-nova 654).
MV Lyr (RA = 19h07m15s.93, Dec = +44d01'10".7)
The object is rather steady at around 13.4mag
(vsnet-campaign-nl 51).
WZ Sge (RA = 20h07m36s.53, Dec = +17d42'15".3)
The slow fading still continues. The object is now about 14.9mag
(vsnet-campaign-dn 1870, 1882).
BL Lac (RA = 22h02m42.86s, Dec = +42d16'37.6")
The object was slightly brighter (vsnet-campaign-blazar 231).
RU Peg (RA = 22h14m02s.58, Dec = +12d42'11".4)
The object is rather active around about 12.2mag
(vsnet-campaign-dn 1873).
DW Cnc (RA = 07h58m56s.80, Dec = +16d16'48".2)
The object is still acrive (vsnet-campaign-dn 1874,
vsnet-campaign-nl 52).
*** 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 ***
1RXS J232953.9+062814
Superhump light curve by the Kyoto team:
http://ftp.kusastro.kyoto-u.ac.jp/pub/vsnet/DNe/J2329/hump.gif
[vsnet-campaign 1214]
Image during the outburst by the Kyoto team:
http://ftp.kusastro.kyoto-u.ac.jp/pub/vsnet/DNe/J2329/im.gif
[vsnet-campaign 1215]
VSNET web page:
http://vsnet.kusastro.kyoto-u.ac.jp/vsnet/DNe/J2329.html
[vsnet-campaign 1216]
ROSAT CVs in Jingyao, H. et al., 1998, Ann. Shanghai Obs., Acad. Sin.,
19, 235
1RXS_J012750.5+380830 012750.60 +380812.0 R=16.8 (UG:)
1RXS_J062518.2+733433 062516.23 +733438.9 R=14.5 (UG:)
1RXP_J113123+4322.5 113122.40 +432238.0 R=14.9 (UG:)
1RXS_J230949.6+213523 230949.28 +213519.0 R=15.6 (*)
[vsnet-campaign 1217]
TK4
revised chart presented by A. Henden:
http://ftp.nofs.navy.mil/pub/outgoing/aah/temp/tk4v.jpg
[vsnet-campaign-dn 1865, 1866]
WZ Sge
eclipse ephemeris, see [vsnet-campaign-dn 1883]
(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