[Message Prev][Message Next][Thread Prev][Thread Next][Message Index][Thread Index]

[vsolj-alert 848] VSNET Weekly Campaign Summary



From owner-vsnet-campaign@kusastro.kyoto-u.ac.jp Tue Jan  2 05:19 JST 2001
To: vsnet-campaign
Date: Tue, 02 Jan 2001 05:19:51 +0900
From: Makoto Uemura <uemura@kusastro.kyoto-u.ac.jp>
X-Distribute: distribute [version 2.1 (Alpha) patchlevel=24]
Subject: [vsnet-campaign 644] VSNET Weekly Campaign Summary
Content-Type: text
Content-Length: 9353


VSNET Weekly Campaign Summary
 
*** Last week news ***

(new targets)
  Possible Nova in Pup	(RA = 07h37m56s.91, Dec = -25d56'59".7)

    Kazuyoshi Kanatsu (Matsue, Shimane, Japan) reported the discovery
  of a new variable star, which is likely a nova based on the absence
  of apparent counterparts on his previous image, DSS and 2MASS.
  His discovery magnitude is mag 8.7p on December 22.  K. Takamizawa 
  (Nagano, Japan) reported prediscovery observations (November 28, 8.6p mag) 
  on his patrol films.  Takamizawa reported that the object was not recorded 
  on 22 films (limiting magnitude 14) between 1994 March 14 and 1999 
  December 3.  He further reported the presence of a close companion of 
  14.5 mag USNO star(vsnet-campaign-nova 94).  This USNO star is recorded 
  by 2MASS survey, which gives J=12.50, H=11.75, Ks=11.51, not particularly 
  red among neibouring stars.  K. Takamizawa performed photometry of this 
  companion star (vsnet-campaign-nova 101).  H. Abe performed astrometry 
  and determined above position of the possible nova (vsnet-alert 5492).  
  This position agrees that of the USNO star within 1-2 arcsec.  
  If this star is indeed the progenitor of the erupting object, the color 
  from the comparison between the visual and 2MASS magnitudes becomes 
  V-J = +2.  The color is not particularly red in this field.  Even assuming 
  that the object is not significantly reddened, the color is still bluer 
  than most of symbiotic stars, which have V-J colors of +3 to +5 or even 
  larger.  If the object is a nova, the color suggests either a) usual 
  cataclysmic variable with moderate reddening or b) cataclysmic-type binary 
  with a relatively evolved secondary (vsnet-campaign-nova 104).


  UV Gem		(RA = 06h38m44s.51, Dec = +18d16'05".6)
	
    R. Stubbings reported that the SU UMa-type dwarf nova UV Gem is 
  in outburst at 15.0 on December 27.  Even outburst at this magnitude 
  can be a superoutburst (as in 1999 December one)(vsnet-campaign 628).
  The observed magnitude of 15.1mag on December 28 indicates no significant 
  fading (vsnet-campaign-dn 362). 


  TT Ind		(RA = 20h33m39s.79, Dec = -56d33'43".8)

    As reported by R. Stubbings on December 27, TT Ind is in outburst 
  at 13.5mag (vsnet-campaign 629).  The object became brighter (13.0mag) 
  on December 28 as reported by R. Stubbings (vsnet-campaign-dn 361).

 
(continuous targets)
  RZ Leo		(RA = 11h37m22s.27, Dec = +01d48'58".9)

    From the observation on December 25 by the Kyoto team and S. Kiyota, 
  T. Kato reported the superhumps with narrower peaks and with an amplitude 
  of 0.35 mag (vsnet-campaign 623).  A light curve observed by G. Masi 
  shows one "early superhump" maximum on December 22 (vsnet-campaign 624).  
  The data until December 26 by the Kyoto team, S. Kiyota, and R. Novak, 
  yielded a superhump period of 0.07851 d, which is slightly shorter than 
  the previous determination.  This may suggest a shortening of the 
  superhump period.  In the light curve on December 26, superhumps have 
  become narrower, more resembling those of usual SU UMa type stars.  
  Secondary superhump maxima (small notches) were visible both on Tsukuba 
  and Kyoto data (vsnet-campaign 626).  An analysis of RZ Leo observations 
  obtained by T. Vanmunster combined with data supplied by J. Pietz, 
  revealed a fairly simple superhump signal at 0.0785 +- 0.0002 d. 
  This yields a fractional period excess of 3.3%, which is a rather standard 
  excess value (vsnet-campaign 630).  From a steep fading seen in December 
  27 data by the Kyoto team and S. Kiyota, T. Kato suggested there seems to be 
  a wavy pattern with a period of 2-3 d in the averaged light curve.  
  This is likely caused by the beat phenomenon between the superhump period 
  and the orbital period, a natural consequence of a high-inclination system 
  (vsnet-campaign 633).  A brightening which was seen in the Kyoto team 
  data on December 28 is consistent with the presence of the beat 
  phenomenon (vsnet-campaign 637).  The analysis of all VSNET collaboration 
  data since December 23.5 UT up to the Kyoto December 29 full run has 
  yielded the best superhump period of 0.07863 d (vsnet-campaign 640).
  J. Pietz presented two light curves at his web site (see below "General 
  Information"; vsnet-campaign-dn 354).  A. Oksanen provided the data on 
  December 27 and 28 at [vsnet-campaign 634].  The superoutburst is now 
  ongoing.


  WY Tri		(RA = 02h25m12s.08, Dec = +33d00'31".5)

    M. Uemura (Kyoto team) reported a rapid fading of WY Tri on December 27. 
  The first confirmed superoutburst was terminated (vsnet-campaign-dn 368).
  Observations by the Kyoto team and R. Novak yielded the best candidate of  
  the superhump period to be 0.078483 day(vsnet-campaign-dn 376).  
J. Pieatz presented light curves at his web site (see "General Information"; 
  vsnet-campaign 641).

 
  UV Per		(RA = 02h10m13s.58, Dec = +57d11'26".8)

    From the observation on December 25 at Kyoto, T. Kato reported 
  the detection of growing superhumps whose amplitude grew from
  less than 0.1 mag to 0.15 mag, and relatively rapid fading (0.3 mag/d).  
  The superhump period was somewhat longer than that obtained by other 
  authors on earlier superoutbursts.  This suggests that the superhump 
  was still is in its unsteady phase.  It is also striking to note such 
  an early appearance of superhumps in such a short period system 
  (vsnet-campaign 622).  The Kyoto data on December 26 shows that UV Per 
  had risen by ~0.5 mag compared to December 25.  Fully grown superhumps, 
  with amplitudes nearly 0.4 mag, were seen (vsnet-campaign 627).  
  The Kyoto data on December 27 show smooth superhumps with an amplitude 
  of 0.25 mag, and the rising stopped, and the object is apparently at 
  maximum (vsnet-campaign 632).  The object has been steadily fading 
  since December 28.  Clear superhumps with an amplitude of 0.2 mag are 
  present in the light curve on December 28 (vsnet-campaign 636).  
  T. Kato reported the analysis of combined data with Kyoto and B. Martin's 
  observations, the best superhump period is determined as 0.06661 d 
  (after the evolution of full superhumps), which is slightly longer than 
  the previously published period (vsnet-campaign 639).  The object 
  showed somewhat rapid fading on December 29 (vsnet-campaign-dn 371, 372).  
  J. Pietz presented a light curve at his web site (see "General Information"; 
  vsnet-campaign 641).  T. Kato presented a light curve obtained by 
  VSNET collaboration team at vsnet ftp site (see "General Information"; 
  vsnet-campaign 642).  The superoutburst is now ongoing.


  BL Lac		(RA = 22h02m42.86s, Dec = +42d16'37.6")

    The observation reported by T. Kinnunen showed temporary fading (14.8mag) 
  on December 27 (vsnet-campaign-blazar 121).


  TV Col		(RA = 05h29m25s.5, Dec = -32d49'05".2)
    
    Following the last outburst on December 24, no major outburst is not 
  observed on December 25 and 26 (vsnet-campaign-ip 23).


  OJ 287		(RA = 08h51m57s, Dec = 20d17'59")
   
    The bright state continues.  The current magnitude is about 14.4 
  (vsnet-campaign-blazar 120).


  3C 66A		(RA = 02h22m39s.6, Dec = +43d02'08")
    The object further brightened to 14.0mag on December 28 as reported by 
  M. Simonsen (vsnet-campaign-blazar 119).

 
  Delta Sco		(RA = 16h00m19s.9, Dec = -22d37'17")

    Some observations confirmed Delta Sco is still bright 
  (vsnet-campaign-be 72, 73).    

   
*** Future schedule ***

  TV Col campaign conducted by A. Retter (2001 January 2 - 15):

    "Recently using previously published data, we discovered evidence for
     another periodicity in the light curve of TV Col. The 6.4-h period would
     be the longest recorded positive superhump. To confirm this period, I'll
     carry out continuous photometry on TV Col during two weeks in January
     (2-15) using the 0.75-m reflector with the UCT CCD in Sutherland, South
     Africa.

     I am calling for a campaign on TV Col during these nights. As the
     candidate periodicity is relatively long, multi-longitude continuous
     monitoring of the object is extremely important to reduce the aliasing
     problem. So, if you can observe the object for at least ~4 h (preferably
     more than one 6.4-h cycle), please let me know."

   for more information, see [vsnet-campaign 579],[vsnet-campaign-ip 15]


*** General information ***

  RZ Leo 
    Lightcurves presented by J. Pietz:
	http://home.t-online.de/home/Jochen.Pietz/rzleo1.gif
	http://home.t-online.de/home/Jochen.Pietz/rzleo2.gif
						[vsnet-campaign-dn 354]
  WY Tri
    Lightcurves presented by J. Pietz:
	http://home.t-online.de/home/Jochen.Pietz/wytri1.gif
        http://home.t-online.de/home/Jochen.Pietz/wytri2.gif
						[vsnet-campaign 641]
  UV Per
    Lightcurves presented by J. Pietz:
	http://home.t-online.de/home/Jochen.Pietz/uvper1.gif
						[vsnet-campaign 641]
    VSNET collaborator's light curve presented by T. Kato:
	http://ftp.kusastro.kyoto-u.ac.jp/pub/vsnet/DNe/UV_Per/001229.gif
						[vsnet-campaign 642]

  The summary of the VSNET Weekly Campaign Summaries in 2000 
  "VSNET 2000" is available at:
	http://vsnet.kusastro.kyoto-u.ac.jp/vsnet/Summary/vsnet2000.html


(This summary is reproduction free.)

Regards,
Makoto Uemura




VSNET Home Page

Return to Daisaku Nogami


vsnet-adm@kusastro.kyoto-u.ac.jp