[新闻] S&T变星观测预警！

This Is SKY & TELESCOPE's AstroAlert for Variable Stars
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                      ***  News from VSNET  ***

NSV 10934 has firmly been established to be an SU UMa-type dwarf nova.

 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.

&nbsplease refer to the VSNET Home Page for more details of events and
objects listed.

      VSNET Home Page: http://www.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 January 6, 2003, as VSNET campaign
circulation 1361
[Note a large part of detailed information is posted to vsnet-campaign
sub-lists].

VSNET Weekly Campaign Summary

*** Last week news ***

(new targets)
 NSV 10934             (RA = 18h40m52s.26, Dec = -83d43'10".24)

   On January 2, R. Stubbings detected an outburst to 15.0mag of
 NSV 10934.  The object further brightened to 12.0-11.9mag on January
 2 and 11.4mag on January 3.  This is the brightest outburst ever
 observed by the VSNET members; the outburst was suspected to be a
 superoutburst (vsnet-campaign-dn 3219, 3222, 3228,
 vsnet-campaign-news 190).  The light curve obtained by C. Stockdale
 on January 3 was rather flat (vsnet-campaign-dn 3236).  The
 following time-series observation by B. Monard on January 3 showed
 modulations up to 0.1mag with no clear periodicity
 (vsnet-campaign-dn 3233).  On January 4, clear superhumps were
 detected by C. Stockdale.  The amplitude of superhumps was ~0.15mag
 and its period was estimated to be 0.0743(8) d.  The object is now
 firmly established to be an SU UMa-type dwarf nova
 (vsnet-campaign-dn 3228).  The light curve also showed a possible
 QPOs (vsnet-campaign-dn 3239).  On January 5, the superhumps further
 grown to a full amplitude of 0.3mag or even greater.  The best mean
 superhump period was 0.07615(6) d.  There seems to have been a rapid
 period change during this evolution period (vsnet-campaign-dn
 3253). The superoutburst is now ongoing (vsnet-campaign-dn 3242,
 3243, 3257).


 VW Tuc         (RA = 00h20m19s.08, Dec = -73d52'07".9)

   As reported by R. Stubbings, a possibly rare outburst (15.1mag) of
 the dwarf nova VW Tuc started on January 2.  Although there have
 been substantial gaps between observations, the last reported
 outburst occurred in 1997 November.  The object is in the SMC field,
 and is also known as SMC V0012 = HV 6327 (vsnet-campaign-dn 3220).
 B. Monard reported it was 15.6CR mag on January 3 (vsnet-campaign-dn
 3232), and the fading trend was confirmed on January 4
 (vsnet-campaign-dn 3245).  In light curves on January 3 and 4
 observed by P. Nelson and B. Heathcote, no apparent superhumps were
 observed, suggesting that the object is an SS Cyg-type (UGSS) dwarf
 nova.  The mean decline rate was 0.4 mag/d, which implies a moderate
 orbital period (vsnet-campaign-dn 3254).


 TU Tri (RA = 01h39m15s.41, Dec = +31d24'19".3)

   An outburst (14.6mag) was reported by M. Simonsen on January 1.
 The last reported possible outburst was in 1998, by T. Kinnunen.
 Further two outbursts were recorded in 1995 by M. Iida's CCD
 monitoring.  It may be possible that many outbursts have escaped
 visual detection because of the faintness (vsnet-campaign-dn 3216).
 K. Torii confirmed that it was still in outburst on January 4, and
 the resultant light curve showed no superhumps, likely indicating
 that this object is an SS Cyg-type dwarf nova (vsnet-campaign-dn
 3237, 3262).  The object has faded (vsnet-campaign-dn 3247).


 SN 2002kf (RA = 06h37m15s.31, Dec = +49d51'10".2)

   SN 2002kf was discovered by S. Brady on an image taken on December
 27 when it was about 15.9mag.  CGCG 233-023, a host galaxy of SN
 2002kf is a small galaxy near the Galactic plain (vsnet-campaign-sn
 524).  The CfA team revealed that it was type Ia SN near the maximum
 at Dec. 31.34 UT.  The expected maximum is consistent with the
 discovery magnitude (vsnet-campaign-sn 525).


 L414, L940, L96

   M. Regalado reported three new red variables, L414, L940, L96.
 With more than 320 observations by A. Violat and T. Benasar, they
 estimated periods of 107.35 d for L414 and 143.68 d for L940
 (vsnet-campaign-unknown 170).


 V485 Cen (RA = 12h57m23s.30, Dec = -33d12'06".8)

   An outburst (14.0mag) of an ultrashort-period (Porb = 59 min)
 system was reported on January 3 by R. Stubbings.  The last outburst
 (superoutburst?) was reported in 2002 August (vsnet-campaign-dn
 3230).  It was still in outburst on January 4 and 5 without rapid
 fading, which indicate that it is a superoutburst.  The supercycle
 of 160 d seems to be now established (vsnet-campaign-dn 3244, 3260).


 MKN 421 (RA = 11h04m27s, Dec = +38d12'32")

   The object was reported brighter by G. Poyner on January 4
 (vsnet-campaign-blazar 293).


 FI Cas (RA = 00h06m10s.07, Dec = +55d58'51".1)

   M. Linnolt reported that FI Cas was bright at 15.0mag on January
 4 (vsnet-campaign-dn 3250).  K. Torii confirmed the outburst on
 January 5 at about 15.5mag (vsnet-campaign-dn 3252).  


 UV Gem (RA = 06h38m44s.16, Dec = +18d16'11".5)

   As reported by R. Stubbings on January 5, UV Gem is undergoing a
 possible superoutburst (14.4mag).  Although the SU UMa-type nature
 of UV Gem has been established, there has been a report that at
 least one of long outburst did not show clear superhumps.  Further
 observations are clearly needed (vsnet-campaign-dn 3255, 3258).


(continuous targets)
 V1208 Tau (RA = 04h59m44s.00, Dec = +19d26'23".7)

   A clear growth of secondary superhumps were observed in the end of
 December (vsnet-campaign-dn 3215).  On January 3, T. Kato reported
 that there may be some hint of beat-like modulation of the mean
 brightness (vsnet-campaign-dn 3224).  The superoutburst continues
 (vsnet-campaign-dn 3231, 3263).


 GZ Cnc (RA = 09h15m51s.70, Dec = +09d00'50".2)

   On January 4, a new outburst (13.3-13.4mag) was reported by
 R. Stubbings (vsnet-outburst 5015).  The observations by the VSNET
 collaboration team since the last outburst showed that there have
 always been quasi-periodic variations with periods 1 hr or slightly
 shorter (vsnet-campaign-dn 3240, 3246).  In a new light curve by
 K. Torii on January 4, there seemed to exist persistent short-period
 (i.e. relative to orbital) variations (vsnet-campaign-dn 3251).


 SN 2002ap             (RA = 01h36m23s.85, Dec = +15d45'13".0)

   A. Henden reported that the object was V=19.5 on December 31.  He
 commented that  there is an underlying star-formation region at this
 location, so further quality photometry will have to wait until the
 SNe fades (vsnet-campaign-sn2002ap 207, 208).


 OJ287                 (RA = 08h51m57s, Dec = 20d17'59")

   The active state still continues (vsnet-campaign-blazar 294).


 DI UMa (RA = 09h12m22s.16, Dec = +50d49'39".1)

   A new outburst (15.4mag) was reported by G. Poyner on January 4
 (vsnet-campaign-dn 3259).


 AT Cnc (RA = 08h28m36s.92, Dec = +25d20'02".6)

   The object is still in a standstill (vsnet-campaign-dn 3248).


 RX J1155.4-5641 (RA = 11h55m27s.0, Dec = -56d41'53")

   On January 3, the object brightened again following a
 superoutburst (vsnet-campaign-dn 3229).


 BU Tau (RA = 03h49m11s.19, Dec = +24d08'12".4)

   D. West reported that BU Tau has not actually brightened, but
 HD 23873, which was a comparison star he used, has apparently faded
 (vsnet-campaign-be 207).  On the other hand, S. Otero reported that
 his observation on January 5 showed no fading of HD 23873
 (vsnet-campaign 1359).  D. West reported that BU Tau hasn't changed
 in H beta magnitude since the observation of The Hauck and
 Mermilliod 1998 catalog (vsnet-campaign-be 208, vsnet-campaign 1360).  

   
 V844 Her              (RA = 16h25m01s.69, Dec = +39d09'25".9)

   The superoutburst continues (vsnet-campaign-dn 3218).


 V803 Cen (RA = 13h23m44s.5, Dec = -41d44'30".1)

   It again showed a bright outburst (12.8mag) on December 31, as
 reported by R. Stubbings (vsnet-campaign-dn 3217).  The outburst
 quickly faded on January 2 (vsnet-campaign-dn 3223).  It again
 brightened to 14.4mag on January 4 (vsnet-campaign-dn 3249).


 RR Tau (RA = 05h39m30s.53, Dec = +26d22'26".3)

   The object is now recovering from the last deep fading
 (vsnet-campaign-orion 39).


 U Gem                 (RA = 07h55m05s.55, Dec = +22d00'09".2)

   The object is fading from the outburst (vsnet-campaign-dn 3214, 3221).


 MisV1147 (RA = 22h54m03s.78, Dec = +58d54'02".1)
 
   It has brightened from the last fading in the end of December
 (vsnet-campaign-unknown 169).


 V854 Cen (RA = 14h34m49s.8, Dec = -39d33'18")

   It is now faint, as reported to be 13.5mag by R. Stubbings on
 December 31 (vsnet-campaign-rcb 87).


 ASAS 000155-6707.7    (RA = 00h01m54s.2, Dec = -67d07'49")

   M. Morel commented that this variable is included in the Downes &
 Shara _Living Edition_ of their Catalog and Atlas of CVs under the
 name 1RXS J0001-6707, with max. mag of 13.4.  The ASAS3 catalogue
 gives a light curve, showing two maxima which have the
 characteristic rapid rise and fall of a UG star, but the amplitude
 is a bit small, only 2.5 mag (vsnet-campaign-dn 3256).


*** Future schedule ***

 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://www.uv.es/2003supernovae/
[vsnet-campaign-sn 342]
[vsnet-campaign-sn 452]
[vsnet-campaign-sn 512]

*** General information ***

 VW Tuc
   Chart and Preliminary Sequence provided by M. Simonsen:
     http://joevp.20m.com/charts/provisional/
[vsnet-campaign-dn 3225]
   Information of comparison stars by B. Skiff, see
     [vsnet-campaign-dn 3227]

   Image taken by B. Monard:
     ftp://vsnet.kusastro.kyoto-u.ac. ... VW_Tuc/vwtucmon.gif
[vsnet-campaign-dn 3234]
   Image taken by B. Heathcote:
     ftp://vsnet.kusastro.kyoto-u.ac. ... W_Tuc/heathcote.jpg
[vsnet-campaign-dn 3241]
   Image taken by P. Nelson:
     ftp://vsnet.kusastro.kyoto-u.ac. ... e/VW_Tuc/nelson.jpg
     ftp://vsnet.kusastro.kyoto-u.ac. ... e/VW_Tuc/nelson.gif
[vsnet-campaign-dn 3261]
 NSV 10934
   Chart and Preliminary Sequence provided by M. Simonsen:
     http://joevp.20m.com/charts/provisional/
[vsnet-campaign-dn 3226]
   Image taken by C. Stockdale:
     ftp://vsnet.kusastro.kyoto-u.ac. ... 0934/stockdale1.gif
   Image taken by B. Monard:
     ftp://vsnet.kusastro.kyoto-u.ac. ... NS10934/monard1.gif
[vsnet-campaign-dn 3235]
   Superhump profile:
     ftp://vsnet.kusastro.kyoto-u.ac. ... /NSV10934/nsvsh.gif
   VSNET Special Page:
     http://www.kusastro.kyoto-u.ac.jp/vsnet/DNe/nsv10934.html
[vsnet-campaign-dn 3239]
 ASAS 000155-6707.7
   Sequence, see [vsnet-campaign-dn 3256]

 V838 Mon
   Recent multicolor observations by S. Kiyota, see
     [vsnet-campaign-v838mon 406]
     (also see, [vsnet-campaign-v838mon 407, 408]

 VSNET 2002
   The annual review of [vsnet-campaign] is now available from the
   top page of VSNET, or directly at:
   http://vsnet.kusastro.kyoto-u.ac ... 2002/vsnet2002.html


(This summary can be cited.)

Regards,
Makoto Uemura