[vsnet-alert 9904] Discovery of optically violently variable quasar QSO B0133+47

Seiichi Yoshida comet at aerith.net
Sun Feb 10 02:36:45 JST 2008

Dear colleagues,

We discovered a quasar QSO B0133+47 is an optically violently variable
QSO in the course of the MISAO Project. 


# Execuse me, but this is just a summary report. As this list is for
  alert notification, I will not post any further discussions of this
  quasar to this list. I will add further information to the web page
  above. Of couser, I will post to this list if I get a new alert event ;-)

The variation of this quasar was discovered by Seiichi Yoshida (MISAO
Project) in the MISAO Project nova survey. It was picked up as one of
the nova candidates from Youichirou Nakashima (Okayama, Japan)'s
unfiltered CCD images on 2007 Nov. 11 by the PIXY System 2. Yoshida
checked Nakashima and Nobuo Ohkura (Okayama, Japan)'s CCD images
between 2000 and 2007, and confirmed that the object is a real

Here are the data of this quasar:

  QSO B0133+47  QSO  01 36 58.5948 +47 51 29.100  18.0V
  DA 55  01h36m58s.6 +47o51'29"  19.5 mag(O)  -24.4 mag(abs)  z=0.859
  USNO-A2.0 1350.01532368  01h36m58s.635 +47o51'29".19  Mag(R):18.3  Mag(B):18.5

It is recorded as a very faint object at 18-19 mag in these catalogs.
However, it was so bright as 14 mag in 2007 November by the MISAO
Project observations.

Quasar is a very distant active galactic nucleus. It is usually
recorded by radio observations, but also optically visible. The radio
flux is variable, and it also changes its brightness optically.
However, Taichi Kato (Kyoto University) commented that a quasar with
such a large amplitude is rare. 

This quasar will be classified as a blazar called "optically violently
variable QSO". Kazuya Ayani (Bisei Observatory) commented that it is a
rare type among quasars. This quasar is about 7 billion light years
from our planet, and the apparent brightness of 14 mag is
extraordinary at this distance.

This quasar has been well researched in the radio observations and
known to be radio variable, however, little observed optically. Nobody
has noticed that this quasar becomes so bright. 

Therefore, we the MISAO Project registered it as the 1436th new
variable star, and assigned the designation "MisV1436".

    R.A.  01h36m58s.63
    Decl. +47o51'29".0  (2000.0)
    Mag.  14.1-16.6C
    Type  OVV-QSO


Here are the observation data by the MISAO Project:

  2000 Dec.  1.47  16.2 mag  (*1)
  2001 Dec. 11.46  15.5 mag  (*1)
  2002 Jan.  2.40  16.6 mag  (*1)
  2007 Sept.12.81  15.4 mag  (*2)
       Oct.  6.75  15.3 mag  (*3)
       Nov. 11.63  14.1 mag  (*2)
       Dec.  3.52  14.9 mag  (*2)

  (*1) Nobuo Ohkura  500-mm camera lens + SBIG ST-8
  (*2) Youichirou Nakashima  7.6-cm f/6.6 refractor + SBIG ST-8
  (*3) Nobuo Ohkura and Youichirou Nakashima  7.6-cm f/6.6 refractor + SBIG ST-8

I also investigated the past brightness of this quasar in the
Digitized Sky Survey POSS-I / POSS-II plates using:

  USNO Flagstaff Station Integrated Image and Catalogue Archive Service

I selected one star with similar brightness around the quasar in each
plate. Here is the list with the magnitude in the USNO-A2.0 catalog.

  Date       Star with similar brightness to the quasar, and its brightness
  1953.7810  18.7 mag  USNO-A2.0 1350-01532664  18.6R  18.9B
  1953.7810  18.7 mag  USNO-A2.0 1350-01532664  18.6R  18.9B
  1989.7426  17.8 mag  USNO-A2.0 1350-01531592  17.7R  17.9B
  1989.7509  17.8 mag  USNO-A2.0 1350-01531592  17.7R  17.9B
  1990.8268  18.7 mag  USNO-A2.0 1350-01532664  18.6R  18.9B
  1991.7577  19.0 mag  USNO-A2.0 1350-01532064  18.7R  19.5B
  1992.8008  18.7 mag  USNO-A2.0 1350-01532664  18.6R  18.9B
  1992.9760  17.2 mag  USNO-A2.0 1350-01533365  16.9R  17.8B
  1993.6222  15.8 mag  USNO-A2.0 1350-01532017  15.6R  16.1B
  1993.7235  17.0 mag  USNO-A2.0 1350-01530812  16.9R  17.1B
  1995.8207  15.8 mag  USNO-A2.0 1350-01532017  15.6R  16.1B
  2007.8620  14.2 mag  USNO-A2.0 1350-01538026  13.9R  14.8B  (*4)

It has been so faint as around 18 mag until 1992. But small outbursts
have occurred twice in 1993 and 1995.

However, the quasar was much brighter than any past DSS plates in the
MISAO Project CCD images on 2007 November 11 (*4). The MISAO Project
succeeded to catch its brightest record in the history.

John Greaves investigated the UCAC2 and CMC14 catalogs. The UCAC2
catalog lists this quasar as 14.3 mag, which suggests this quasar was
very bright around mid July in 2002. The CMC14 catalog lists it as
15.0 mag, which also suggests it was bright around late 2002. The
standard deviation of the CMC14's magnitude is over 0.7 mag, which
suggests this quasar's variation.

Reinder J. Bouma searched the Skymorph archive and found that this
quasar was bright as 15.0 mag on 2002 September 24. 

No records brighter than 18 mag have been found before 1992, and no
records fainter than 17 mag have been found after 1995. This quasar
may became very active in recent years.

Ayani commented that this quasar is highly polarized, typical for a
large optical variation. The spectrum in the following literature
shows broad emission lines, which supports that this quasar is
classified as an "optically violently variable QSO", not a BL Lac


Greaves introduced the radiograms of this quasar at the NASA/IPAC
Extragalactic Database. Greaves commented that this object has a
relativistic radio jet, and the radio variability looks to stem from
the interaction of this jet.

  Images and maps in NED archive for object [HB89] 0133+476

About the MISAO Project and the PIXY system 2:

Best regards,

Seiichi Yoshida
comet at aerith.net

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