15 Feb 2016

Photo Alert: A bright active Blazar [Mag 13.8] is now exciting Indian Astronomers

A blazar is a very compact quasar (quasi-stellar radio source) associated with a presumed supermassive black hole at the center of an active, giant elliptical galaxy. Blazars are among the most energetic phenomena in the universe and are an important topic in extragalactic astronomy.
 
Many of these exotic deep sky objects are faint, and very few are in range of amateur size telescope, however, Indian astronomers are now observing at active Blazar named OJ 287 of Mag 14 in the Constellation of Cancer, located to the left of M44 the Praesepe, which is increasing in brightness. An active jet is now coming into view and pointing in the direction of the Earth.
RA 08h 54m 54.48s DEC + 20 06' 14.40"
Astro photographers are urged to image the Blazar over the coming nights to monitor its activity as It could brighten to Mag 12.9.  If you do obtain images I would like to use them in a future program, please send them to rprarson46@yahoo.com.
Please click on the images to enlarge.


 
The astronomers report UBVRI photometric and polarimetric observations of the BL Lac object OJ 287 made on 12 February 2016. This object was recently detected in a high activity state. The polarimetry was carried out with a two beam, broadband, three channel polarimeter attached to the 1 m Carl Zeiss telescope at Vainu Bappu, India.
 
The polarimetric observation listed against the ‘R' band was made in integrated light in the VRI spectral region. The Visual mag and the broadband colours obtained are: V = 14.4, U-B = -0.50, B-V = 0.50, V-R = 0.40, V-I = 1.70. The uncertainty in Visual is around 0.1 mag, while that of a broadband colour is around 0.05 mag.


 
The Indian astronomers also report the temporal brightness variation of OJ 287 on the same night. The photometric observations were made in R band with a TEK 1k x 1k CCD camera attached to the 0.75-m telescope at VBO. Differential R magnitudes of OJ 287 with respect to a comparison star (J2000.0: R.A.= 08:54:54.48, Dec.=20:06:14.40; R = 14.34 mag).
 
OJ287 has been monitored in the optical wavelength with small telescopes since the beginning of September, 2015. In November and December, an unprecedented outburst in the optical band was noticed, with OJ287 reaching 12.9 mag in the Red filter. This outburst, with a possible significant thermal component, was followed by two flares of smaller amplitudes with maxima occurring on Dec 22, 2015 and January 12, 2016, originating in the jet.
The renewed optical activity of OJ287 that started on February 5. 2016. The Brightness of OJ287 rapidly rose from about 15 Mag (Feb 5) to 13.87 (Feb 10) in the R band. Most recent observation taken with PROMPT5 at 3 UT, Feb 10, indicate the target to be still increasing its brightness. On Feb 3 the degree of polarization measured using the RINGO3 polarimeter on the Liverpool Telescope was ~10%, rising to ~17% on Feb 7 and to 18-19% on Feb 8. This may also confirm the flare to be of jet origin.
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