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[vsnet-campaign-news 183] News from VSNET
*** News from VSNET ***
A superoutburst of CT Hya started.
RX And may have entered a low state.
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 18, 2002, as VSNET campaign
circulation 1349
[Note a large part of detailed information is posted to vsnet-campaign
sub-lists].
VSNET Weekly Campaign Summary
*** Last week news ***
(new targets)
CT Hya (RA = 08h51m04s.50, Dec = +03d07'43".5)
As detected by R. Stubbings on November 11, the large-amplitude
SU UMa-type dwarf nova CT Hya is now in a superoutburst. The last
reported superoutburst occurred in 2000 December. The star was
claimed to be something intermediate between usual SU UMa stars and
WZ Sge-type stars, see Nogami et al. 1996 (vsnet-campaign-dn 3020).
The data on November 12 taken by K. Torii, indicated the emergence
of superhumps (amplitude 0.10-0.15 mag). A period analysis yielded
a substantially longer period than the previously determined
superhump period (0.06643 d, Kato et al. 1999). This difference
seems to indicate that the object was experiencing the early
development stage of the superhumps (vsnet-campaign-dn 3027). The
light curve on November 13 by K. Torii, clearly showed fully grown
superhumps (amplitude 0.3-0.4 mag). Some QPO-like variations (time
scales ~10 m) were superimposed (vsnet-campaign-dn 3030). The
outburst is now ongoing (vsnet-campaign-dn 3026, 3029, 3038, 3032,
3036).
SN 2002hz (RA = 22h27m49s.54, Dec = +38d35'09".5)
SN 2002hz was discovered by the LOTOSS team on images taken on
November 16, at about 17.8mag. UGC 12044, a host galaxy of SN
2002hz, is an edge-on spiral galaxy with low galactic latitude
(b=-16o). The expected maximum for typical SN Ia (without a
reddening in the host galaxy) is mag about 16.3, but judged from the
reports (0.6 mag rise in 4 days), it is possibly a reddened (or
subluminous) SN Ia or a core-collapse event (vsnet-campaign-sn
507).
SN 2002ia (RA = 01h45m38s.52, Dec = +24d08'07".9)
Wood-Vasey et al. reported the discovery of SN 2002ia on images
taken on Oct. 30 and confirmed on Nov. 13 (at mag 18.6) and 14 (mag
18.5). A host galaxy of SN 2002ia is anonymous and quite dim (USNO
rmag is 19.1). Its appearance on the DSS image suggest that it is
possibly a spiral galaxy (vsnet-campaign-sn 507).
SN 2002hy (RA = 10h54m39s.18, Dec = -21d03'41".2)
SN 2002hy was discovered by B. Monard on images taken on Nov. 12
at 16.4mag. NGC 3464, a host galaxy of SN 2002hy, has also produced
SN Ic 2002J (reported brightest mag = 16.4) in this January
(vsnet-alert 7079). NGC 3464 is an open spiral galaxy, and SN is
superimposed on the inner northern arm. It seems to be a rather
bright core-collapse event (like as SN Ic) or a somewhat reddened SN
Ia near the maximum light (vsnet-campaign-sn 505).
(continuous targets)
KV And (RA = 02h17m13s.85, Dec = +40d41'30".6)
The object has shown a characteristic linear fading since November
6. The November 5 data did not fit this trend, indicating that the
system was still in its early development stage. Superhumps
appeared on all observed nights. There was a hint of secondary
superhumps on November 8 (vsnet-campaign-dn 3028). The object
entered a rapid fading phase on November 16 (vsnet-campaign-dn 3002,
3015, 3035).
RX And (RA = 01h04m35s.55, Dec = +41d17'58".0)
Recent observations indicate that the unusual Z Cam-type dwarf
nova with occasional low states, RX And, may have entered its low
(faint) state. Since the last small outburst around November 3-4,
no brightening has been observed. This small outburst followed a
bright outburst in late November. The present behavior seems to
reproduce the start of the 1996 August-September event. The 1996
August-September event was the first event which revealed the
peculiarity of RX And. The faint state lasted until 1997 January
(vsnet-campaign-dn 3033).
SN 2002hc (RA = 08h17m06s.05, Dec = -27d27'27".0)
H. Yamaoka reported a revised estimation of magnitude on September
9 to be 15.4CR mag based on GSC2.2 Fmag and UCAC1 magnitude. He
claimed that the discovery magnitude reported in IAUC 7999 (mag
about 17) seems to be underestimated (vsnet-campaign-sn 504, 506).
SN 2002hw (RA = 00h06m49s.06, Dec = +08d37'48".5)
The CfA team revealed that it is a type Ia SN a few days
before maximum light but reddened (vsnet-campaign-sn 503).
AT Cnc (RA = 08h28m36s.92, Dec = +25d20'02".6)
The possible standstill continues (vsnet-campaign-dn 3034).
DM Lyr (RA = 18h58m45s.02, Dec = +30d15'39".9)
Observations by K. Torii showed that DM Lyr was still bright on
Nov. 8, and entered the rapid decline stage on Nov. 9
(vsnet-campaign-dn 3022).
SW UMa (RA = 08h36m42s.80, Dec = +53d28'38".2)
The data just before a rapid fading taken by K. Torii, clearly
indicated the late-stage superhumps with diminishing amplitudes
(vsnet-campaign-dn 3021). QPOs were prominent during the rapidly
declining phase on Nov. 9. This finding confirms the 2000 finding
that super-QPOs become prominent during the decline phase from a
superoutburst (vsnet-campaign-dn 3025). On Nov. 10, the rapid
fading stopped. There was a prominent hump feature (0.5 mag), which
is likely a late superhump (vsnet-campaign-dn 3023). The large
amplitude QPOs (periods 3-4 min) were also still prominent
(vsnet-campaign-dn 3024). On November 12, short-period variations
became less prominent. On November 13, the variation became
stronger again (0.1-0.4 mag), some of which look like late
superhumps (vsnet-campaign-dn 3031).
MisV1147 (RA = 22h54m03s.78, Dec = +58d54'02".1)
On November 10, the object was reported to be 14.5mag, which
indicated that the object became fainter again
(vsnet-campaign-unknown 124, 125).
Z And (RA = 23h33m40s.02, Dec = +48d49'06".1)
The outburst is still ongoing. It is now about at 10mag
(vsnet-campaign-symbio 42).
V838 Mon (RA = 07h04m04s.816, Dec = -03d50'50".94)
D. West performed multi-color photometry on November 11 and
reported that V=15.9+/-0.2 and V-Ic=6.1+/-0.2 for V838 Mon and
V-Ic=1.8+/-0.2 for the light echo (vsnet-campaign-v838mon 403, 404,
vsnet-campaign-nova 1145).
GSC 6846:6 (RA 18h03m14s.47, Dec = -25d14'22".1)
D. West reported a fading of this object on November 11
(vsnet-campaign-unknown 126, 127).
MV Lyr (RA = 19h07m15s.93, Dec = +44d01'10".7)
The brightening continued, as reported by S. Shugarov
(vsnet-campaign-nl 99, 100, 101, vsnet-campaign-dn 3037).
*** Future schedule ***
MINE OBSERVATIONS OF CYG X-1
F. Mirabel announced that the INTEGRAL satellite will point to
Cygnus X-1 for 1 million seconds between November 24 and December
6. In the context of the "MINE" collaboration
(http://elbereth.obspm.fr/~fuchs/mine.html), monitoring programs are
recommended for this period.
[vsnet-campaign-xray 166]
For further information, please, be in contact with Yael Fuchs
(yfuchs@discovery.saclay.cea.fr).
IAU Colloquium 194
"Compact Binaries in the Galaxy and Beyond"
17-22 November 2003, La Paz, Mexico
Contact Details
Web page: http://bufadora.astrosen.unam.mx/~iau194
Email: iau194@astrosen.unam.mx
[vsnet-campaign-sn 467]
[vsnet-campaign-xray 154]
Texas in Tuscany
XXI Symposium on Relativistic Astrophysics
Florence, Italy, December 9-13, 2002
For more information:
http://vsnet.arcetri.astro.it/~texaflor/
[vsnet-campaign-xray 142]
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]
*** General information ***
SN 2002hw
Spectrum taken by the CfA team:
http://cfa-www.harvard.edu/cfa/oir/Research/supernova/spectra/sn2002hw-20021111.flm.gif
[vsnet-campaign-sn 503]
CI Aql
Preprint by K. Matsumoto et al.:
http://ftp.kusastro.kyoto-u.ac.jp/pub/vsnet/preprints/CI_Aql/ciaql2.{pdf,ps.gz}
[vsnet-campaign-nova 1146]
V838 Mon
Images using DRIZZLE provided by D. West:
http://members.aol.com/dwest61506/page41.html
[vsnet-campaign-v838mon 405]
(This summary can be cited.)
Regards,
Makoto Uemura
Return to Daisaku Nogami
vsnet-adm@kusastro.kyoto-u.ac.jp
VSNET Home Page