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Strong Millimeter Band Flaring of B2 0827+24 (J0830+241)

ATEL # 2885; Mark A. Gurwell (Harvard-Smithsonian Center for Astrophysics) & Ann E. Wehrle (Space Science Institute)
on 29 Sep 2010; 18:53 UT
Password Certification: Mark A. Gurwell (

Subjects: Millimeter, Quasars
Referred to by ATEL #: 2894

The Submillimeter Array (SMA) performs ongoing flux density monitoring of quasars that are typically bright in the mm/submm bands, in order to optimally choose quasars for use as interferometric calibration sources. In addition, we carry out targeted monitoring projects that have been accepted through our regular proposal submission process. Through these monitoring efforts, we report that the quasar B2 0827+24(=J0830+241, OJ248, EGRET J0831+24) is currently flaring strongly at millimeter wavelengths. B2 0827+24 is a low polarization radio quasar with redshift 0.96. Its V band magnitude measured by Paul Smith (Steward Observatory) on 16 May 2010 was 17.3+/- 0.02 (

Between February and June 2010, the source varied between 0.4 and 1 Jy at 1.3 mm wavelength. On Sept 14 and 28, the source brightened to 2.26 +/-0.12 and 2.92 +/-0.15 Jy. Strong EGRET gamma ray flares in quasars have occurred "preferentially during the rise or peak" of long millimeter-band (22 and 37 GHz) flares (Valtaoja et al. 2002 Publ. Astron. Soc. Aust. 19, 117 and references therein); we particularly encourage attention to the possibility of a gamma ray flare in the next few weeks or months. Continued monitoring at all wavelength bands is encouraged.


The Submillimeter Array is a joint project between the Smithsonian Astrophysical Observatory and the Academia Sinica Institute of Astronomy and Astrophysics, and is funded by the Smithsonian Institution (USA) and the Academia Sinica (Taiwan).

Click here for futher information on the SMA Quasar Flux Density Monitoring project

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