Japanese version Home Page Updated on March 15, 2008
MisV1436: Discovery of Optically Violently Variable Quasar QSO B0133+47
2008 Feb. 10 We discovered a quasar QSO B0133+47 is an optically violently variable QSO in the course of the MISAO Project.
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Field of view: about 12 arcmin. 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 variable. 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".
Here are the observation data by the MISAO Project:
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 Band Star with similar brightness to the quasar, and its brightness --------------------------------------------------------------------------------- 1953.7810 R 18.7 mag USNO-A2.0 1350-01532664 18.6R 18.9B 1953.7810 B 18.7 mag USNO-A2.0 1350-01532664 18.6R 18.9B 1989.7426 R 17.8 mag USNO-A2.0 1350-01531592 17.7R 17.9B 1989.7509 R 17.8 mag USNO-A2.0 1350-01531592 17.7R 17.9B 1990.8268 I 18.7 mag USNO-A2.0 1350-01532664 18.6R 18.9B 1991.7577 R 19.0 mag USNO-A2.0 1350-01532064 18.7R 19.5B 1992.8008 B 18.7 mag USNO-A2.0 1350-01532664 18.6R 18.9B 1992.9760 B 17.2 mag USNO-A2.0 1350-01533365 16.9R 17.8B 1993.6222 B 15.8 mag USNO-A2.0 1350-01532017 15.6R 16.1B 1993.7235 I 17.0 mag USNO-A2.0 1350-01530812 16.9R 17.1B 1995.8207 I 15.8 mag USNO-A2.0 1350-01532017 15.6R 16.1B --------------------------------------------------------------------------------- 2007.8620 CCD 14.2 mag USNO-A2.0 1350-01538026 13.9R 14.8B (*4) 
Palomar plate in 1992 (MisV1436 is 18.7 mag)
Palomar plate in 1993 (MisV1436 is 15.8 mag) 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 object. http://ads.nao.ac.jp//full/1996ApJS..107..541L/0000564.000.html 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 (Supplement on February 10, 2008) Our discovery was announced in CBET 1249. (Supplement on February 14, 2008) SIMBAD query result: http://cdsweb.u-strasbg.fr/cgi-bin/bibobj?2005A%26A...434..449R&0133%2B476 (Supplement on February 26, 2008) Kazuhiro Nakajima's image and observations: http://www.ztv.ne.jp/web/K.Nakajima/Light_curve3/QSO_B133+47.htm
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