SETI bioastro: Fw: BZ UMa Outburst (AAVSO Special MyNewsFlash)

From: LARRY KLAES (ljk4_at_msn.com)
Date: Wed Feb 25 2004 - 16:38:03 PST

  • Next message: LARRY KLAES: "SETI bioastro: Fw: Big Sunspot"

    ----- Original Message -----
    From: aavso_at_aavso.org<mailto:aavso_at_aavso.org>
    To: ljk4_at_msn.com<mailto:ljk4_at_msn.com>
    Sent: Wednesday, February 25, 2004 10:51 AM
    Subject: BZ UMa Outburst (AAVSO Special MyNewsFlash)

    0846+58 BZ UMa appears to be in outburst, its first since December,
    2002. Recent observations:

      FEB 23.1924 16.27 MDW CCDV Err: 0.06
      FEB 23.9215 <14.0 MUY
      FEB 25.2944 11.6 SXN
      FEB 25.3014 11.6 SXN

      MDW MACDONALD II, WALTER J. WINCHESTER, ONTARIO, CANADA
      MUY MUYLLAERT, EDDY OOSTENDE, BELGIUM
      SXN SIMONSEN, MICHAEL A. IMLAY CITY, MI. USA

     Precision time-series CCD observations in V are urgently requested.
    Outbursts tend to be short so please observe as soon as possible and
    for as long as possible. Possible phenomenon to be detected could be
    of very low amplitude so please take care to make your observations
    as precise as possible. Take extra good flat field images and keep
    your SNR high. Please report your error/uncertainty. Observations in
    V are preferred. If you have access to a B filter and a filter wheel
    then consider observing in both B and V, but only if it does not cut
    into your V observation time and lower its SNR.

     AAVSO f-scale charts with B and V CCD data from Henden (USNO) are
    available:
         http://www.aavso.org/cgi-bin/searchcharts3.pl?name=bz%20uma>
     Latest data & light curves:
         
    http://www.aavso.org/cgi-bin/quickquick.pl?star=bz%20uma>

     BZ UMa is classified as a UG by the GCVS. However, it is suggested
    to be a SU UMa subtype due to its short orbital period and mass
    ratio (Jurcevic et. al. PASP 05/1994). If it is a SU Uma, then
    superhumps should be detected in superoutbursts and as of today,
    none have been. However, some evidence of other forms of modulation
    whose cause is unknown have been detected (Ringwald, BAAS 09/1990 &
    Kato, IBVS #4768). It is also a bright X-ray source and it has been
    suggested that this could be a type of intermediate magnetic
    variable (Ishioka et al. 2002, PASJ 54, 581).
     Please submit your observations to the AAVSO as soon as possible.

    Clear skies!
       Aaron Price, Technical Assistant
       on behalf of Elizabeth Waagen, Interim Director
       and Janet A. Mattei, Director
    --------------------------------------------------------------------
    ABOUT AAVSO NEWSFLASH SPECIAL NOTICE:

         AAVSO News Flash Special Notices are sent when
    circumstances warrant to subscribers of the AAVSO MyNewsFlash
    system on an average of one notice per month.

         Archives of Special Notices will be kept at:
          
    http://www.aavso.org/publications/newsflash/special.shtml>

         To unsubscribe from Special Notices simply reply to this
    e-mail. It will not affect your regular MyNewsFlash
    subscription.

    --------------------------------------------------------------------


  • Next message: LARRY KLAES: "SETI bioastro: Fw: Big Sunspot"

    This archive was generated by hypermail 2.1.6 : Wed Feb 25 2004 - 16:49:29 PST