[vsnet-alert 9993] Re: 4C 09.57

[Taichi Kato]

> This is our second optically violently variable quasar discovery,
> after QSO B0133+47 discovered on 2008 Feb. 8. However, we do not know
> whether the variation of this quasar was already known or not.

>   This is well-known blazar (BL Lac-type) OT 081.  The same outburst
> and fading has been reported to VSNET:

   Just for historical reference:

http://adsabs.harvard.edu/abs/1980AJ.....85.1442P

   See description under 1749+09.

  Updated info, including ASAS-3 data, on the 2007 outburst:

  YYYYMMDD(UT)   mag  observer
  20070402.3704 13.885V  (ASAS (Pojmanski, G. 2002, Acta Astron. 52,397))
  20070412.3748 14.451V  (ASAS (Pojmanski, G. 2002, Acta Astron. 52,397))
  20070415.3538 14.085V  (ASAS (Pojmanski, G. 2002, Acta Astron. 52,397))
  20070423.3669 13.982V  (ASAS (Pojmanski, G. 2002, Acta Astron. 52,397))
  20070425.997  14.12CV  (Stefan Karge)
  20070508.206  14.11CV  (Stefan Karge)
  20070510.3118 14.765V  (ASAS (Pojmanski, G. 2002, Acta Astron. 52,397))
  20070516.008  14.52CV  (Stefan Karge)
  20070711.1591 14.611V  (ASAS (Pojmanski, G. 2002, Acta Astron. 52,397))
  20070818.0489 14.997V  (ASAS (Pojmanski, G. 2002, Acta Astron. 52,397))
  20070820.0578 15.008V  (ASAS (Pojmanski, G. 2002, Acta Astron. 52,397))
  20070824.867   148  (Christopher P. Jones)
  20070831.881  14.45CV  (Diego Rodriguez)
  20070904.856   146  (Christopher P. Jones)
  20070904.906  14.40CV  (Diego Rodriguez)
  20070906.860  14.59CV  (Diego Rodriguez)
  20070912.828   148  (Christopher P. Jones)
  20070915.856   151  (Christopher P. Jones)
  20070928.819  15.02CV  (Diego Rodriguez)
  20080203.183  18.19C  (Stefan Karge)
  20080209.208  18.36C  (Stefan Karge)