Superoutburst of Var21 CrB = VW CrB

CCD light curve by R. Novak

VSNET V-band chart

Var21 CrB [UG, 14.5 - <17.5p]
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Tonny Vanmunster, CBA Belgium reports his detection by CCD of an outburst of this CVAP object.

1997 May 9.030 UT, <16.0  (G. Poyner, 0.40-m refl.);
     May 9.880 UT,  14.1  (T. Vanmunster, 0.25-m SCT, unfilt. CCD);

Var21 CrB was last seen in outburst on 1997, Jan 28 by Lasse Jensen, CBA Denmark [CVC 128], at mag. 15.5 (unfiltered CCD image). The object underwent a bright outburst in August 1996 [CVC 104], but failed to reveal any superhumps, despite CCD coverage [CVC 107].

Var21 CrB was discovered by S.V. Antipin [IBVS 4343], who announced two types of outbursts : short ones and long (>15d) ones. The photometric data suggest that the short ones are not necessarily fainter than the long ones. Var21 CrB is located at : R.A. = 16h00m03s.7 and Decl. = +33d11'15" (J2000.0).

Observations!

(vsnet-obs 5742)

Dear colleagues,

I've just made CCD image (and start continuous imaging) of Var 21 CrB. Using R filter (Kron-Cousins) and GSC mag of brightest star in a field (13.2mag) determine Var's magnitude near to 14.7 Because of windy wether can suspect that soon will come clouds. If I'll have some results I'll send them soon. Have a nice day Rudolf

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* Rudolf Novak                              Private:         Rudolf Novak *
* Nicholas Copernicus Observatory                    Bohuslava Martinu 50 *
* Kravi Hora 2                                                BRNO 602 00 *
* BRNO 616 00                                              Czech Republic *
* Czech Republic                                                          *
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*                    e-mail: rudolfn@physics.muni.cz                      *
*                    h-page: http://www.sci.muni.cz/~rudolfn              *
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*             " ... no, There's no dark side of the Moon ... "            *
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Superhumps!

(vsnet-alert 890)

Dear colleagues,

I've just analyzed 115 images (t_exp=90s, R-band, ST-7) of Var 21 CrB. Some light oscilations looks as superhumps were detected. Right now our telescope still observing but high clouds - cirrus- came so realy don't know how suitable will be other images. During first run was not sky clear but light changes with amplitude about 0.3 ~ 0.6 mag are detected. (Comparison stars are constant with deviation from 0.02 to 0.04 mag). I would be very happy if someone could confirm this result through this mailing list or directly to me (adress below). I'll send more analyzis when all images will be done.

Have a nice dreams

Rudolf

New SU UMa star!

(vsnet-alert 892)

Dear colleagues,

We made 4.08 hour long observing run of Var 21 CrB. This CVAP listed object shows superhumps with large aplitude 0.4mag and period aprox. 0.0767 +- 0.0001 d. The star was about 14.6mag in R-band Kron-Cousins filter using mentioned GSC 13.2mag star close to Var 21 CrB position. Light curve will be placed on VSNET and GAMA home page soon. A few points were deleted from dataset beacuse of clouds and sunrise (I went out and found out that Monday definitely come...)

I'm definitely death and going for sleep have a nice day/night and clear sky to confirm this observation. With best regards