[vsnet-alert 10076] Re: Possible start of fading episode of BB Dor

[Taichi Kato]

> BB Dor is about to show why it is classified as a vy scl type novalike.
>
> Regular observations over many years at CBA Pretoria show that BB Dor 
> (EC0528-58)
> normally evolves between magnitudes 13.8 and 14.4 . Lately it has been
> observed to be fainter than that.
> Timeseries photometry last night (17-18 April 2008) show the usual 
> modulation but between 14.4
> and 14.9 and also a gradual fading trend.
>
> The last such fade was in 2002 if I'm not wrong.

  ASAS-3 observations seem to support this fading:

  YYYYMMDD(UT)   mag  observer
  20071113.8090 142CR  (Berto Monard)
  20071114.2837 <14.50V  (ASAS (Pojmanski, G. 2002, Acta Astron. 52,397))
  20071117.2676 14.427V  (ASAS (Pojmanski, G. 2002, Acta Astron. 52,397))
  20071120.3175 14.382V  (ASAS (Pojmanski, G. 2002, Acta Astron. 52,397))
  20071123.2983 14.277V  (ASAS (Pojmanski, G. 2002, Acta Astron. 52,397))
  20071126.1955 <14.50V  (ASAS (Pojmanski, G. 2002, Acta Astron. 52,397))
  20071128.2464 14.319V  (ASAS (Pojmanski, G. 2002, Acta Astron. 52,397))
  20071201.1740 14.277V  (ASAS (Pojmanski, G. 2002, Acta Astron. 52,397))
  20071203.2350 14.872V  (ASAS (Pojmanski, G. 2002, Acta Astron. 52,397))
  20071206.1656 14.089V  (ASAS (Pojmanski, G. 2002, Acta Astron. 52,397))
  20071209.1894 14.394V  (ASAS (Pojmanski, G. 2002, Acta Astron. 52,397))
  20071214.2658 14.020V  (ASAS (Pojmanski, G. 2002, Acta Astron. 52,397))
  20071219.2282 <14.50V  (ASAS (Pojmanski, G. 2002, Acta Astron. 52,397))
  20071222.1260 <14.50V  (ASAS (Pojmanski, G. 2002, Acta Astron. 52,397))
  20071224.2089 <14.50V  (ASAS (Pojmanski, G. 2002, Acta Astron. 52,397))
  20071227.1644 <14.50V  (ASAS (Pojmanski, G. 2002, Acta Astron. 52,397))
  20071229.2465 14.846V  (ASAS (Pojmanski, G. 2002, Acta Astron. 52,397))
  20071229.8690 142CR  (Berto Monard)
  20080101.1598 15.267V  (ASAS (Pojmanski, G. 2002, Acta Astron. 52,397))
  20080103.2782 <14.50V  (ASAS (Pojmanski, G. 2002, Acta Astron. 52,397))
  20080106.2810 <14.50V  (ASAS (Pojmanski, G. 2002, Acta Astron. 52,397))
  20080109.2404 <14.50V  (ASAS (Pojmanski, G. 2002, Acta Astron. 52,397))
  20080112.2566 14.746V  (ASAS (Pojmanski, G. 2002, Acta Astron. 52,397))
  20080115.0914 <14.50V  (ASAS (Pojmanski, G. 2002, Acta Astron. 52,397))
  20080119.1025 14.355V  (ASAS (Pojmanski, G. 2002, Acta Astron. 52,397))
  20080121.1635 <14.50V  (ASAS (Pojmanski, G. 2002, Acta Astron. 52,397))
  20080123.1961 13.952:V (ASAS (Pojmanski, G. 2002, Acta Astron. 52,397))
  20080125.2188 13.478V  (ASAS (Pojmanski, G. 2002, Acta Astron. 52,397))
  20080127.2405 13.879V  (ASAS (Pojmanski, G. 2002, Acta Astron. 52,397))
  20080129.2436 13.580V  (ASAS (Pojmanski, G. 2002, Acta Astron. 52,397))
  20080202.1975 14.510V  (ASAS (Pojmanski, G. 2002, Acta Astron. 52,397))
  20080205.1357 <14.50V  (ASAS (Pojmanski, G. 2002, Acta Astron. 52,397))
  20080207.2250 14.498V  (ASAS (Pojmanski, G. 2002, Acta Astron. 52,397))
  20080210.1250 <14.50V  (ASAS (Pojmanski, G. 2002, Acta Astron. 52,397))
  20080212.2082 14.903V  (ASAS (Pojmanski, G. 2002, Acta Astron. 52,397))
  20080214.1903 <14.50V  (ASAS (Pojmanski, G. 2002, Acta Astron. 52,397))
  20080216.2207 <14.50V  (ASAS (Pojmanski, G. 2002, Acta Astron. 52,397))
  20080220.1340 <14.50V  (ASAS (Pojmanski, G. 2002, Acta Astron. 52,397))
  20080222.1933 <14.50V  (ASAS (Pojmanski, G. 2002, Acta Astron. 52,397))
  20080224.2140 <14.50V  (ASAS (Pojmanski, G. 2002, Acta Astron. 52,397))
  20080226.2065 14.748V  (ASAS (Pojmanski, G. 2002, Acta Astron. 52,397))
  20080229.0765 <14.50V  (ASAS (Pojmanski, G. 2002, Acta Astron. 52,397))
  20080304.1580 <14.50V  (ASAS (Pojmanski, G. 2002, Acta Astron. 52,397))
  20080307.1016 14.840:V (ASAS (Pojmanski, G. 2002, Acta Astron. 52,397))
  20080313.0515 <14.50V  (ASAS (Pojmanski, G. 2002, Acta Astron. 52,397))
  20080315.0682 14.645V  (ASAS (Pojmanski, G. 2002, Acta Astron. 52,397))
  20080317.0813 <14.50V  (ASAS (Pojmanski, G. 2002, Acta Astron. 52,397))
  20080323.1035 <14.50V  (ASAS (Pojmanski, G. 2002, Acta Astron. 52,397))
  20080328.1184 <14.50V  (ASAS (Pojmanski, G. 2002, Acta Astron. 52,397))
  20080331.0336 <14.50V  (ASAS (Pojmanski, G. 2002, Acta Astron. 52,397))
  20080402.0557 14.740V  (ASAS (Pojmanski, G. 2002, Acta Astron. 52,397))
  20080404.1048 <14.50V  (ASAS (Pojmanski, G. 2002, Acta Astron. 52,397))
  20080407.0344 <14.50V  (ASAS (Pojmanski, G. 2002, Acta Astron. 52,397))
  20080409.0621 <14.50V  (ASAS (Pojmanski, G. 2002, Acta Astron. 52,397))
  20080412.0171 <14.50V  (ASAS (Pojmanski, G. 2002, Acta Astron. 52,397))
  20080414.0277 <14.50V  (ASAS (Pojmanski, G. 2002, Acta Astron. 52,397))
  20080416.0543 <14.50V  (ASAS (Pojmanski, G. 2002, Acta Astron. 52,397))

   The 2002 fading (Monard's data)

  YYYYMMDD(UT)   mag  observer
  20020316.722  144CR  (Berto Monard)
  20020318.742  140CR  (Berto Monard)
  20020324.725  145CR  (Berto Monard)
  20020417.741  166CR  (Berto Monard)
  20020428.731  175CR  (Berto Monard)
  20020503.690  <175CR  (Berto Monard)