Blazar Optical Sky Survey (BOSS) Project


Blazar Optical Sky Survey (BOSS) Project is an optical monitoring program, initiated on April 2013 by Dr. Kosmas Gazeas at the University of Athens. It aims at monitoring the optical variability on active Blazars, in parallel with other multi-wavelength observations obtained from space and ground-based observatories.

For further information, visit the BOSS Project official webpage.

Artistic representation of blazars and active galactic nuclei.

Blazar variability timescales are often divided into three categories: the intra-day variability (IDV) which ranges between a few minutes up to one day (Wagner & Witzel 1995), the short-term variability (STV) which ranges between a few days to a few months and the long-term variability (LTV), which covers all variations longer than a few months, up to several years (Gupta et al. 2004).

BOSS Project utilizes the 0.40 m f/8 robotic and remote controlled telescope at the University of Athens Observatory. Continuous observations every night are not always easy to occur, mainly due to weather conditions.

The University of Athens Observatory with telescope and instruments inside the dome.

Sample Light Curves

The photometric light curves of Mrk421 in all optical bands (left). Gray areas mark the periods of brightness peak, while the width of each box represents the duration of each peak and the dashed line the day of maximum brightness.

Continuous monitoring of Mrk421 for a total of 370 days (2013-2014) in R-band (right). Luminosity variations of this highly active blazar can be cross-correlated with orbital data and/or other monitoring campaigns in a wider range of energies.

Multiband sample of Mrk421 data, spreading over the entire electromagnetic spectrum from very high energies (gamma rays on top) to very low ones (radio signal at bottom). Vertical dashed lines on the left represent the moment when the high energy flare occurred on 12 April 2013 (MJD 56394) and the corresponding signals detected a few days later in lower energies.

Target list

In the frame of BOSS Project, the following targets are under monitoring schedule:

BOSS Project Target List


Other Names

RA (J2000)

DEC (J2000)



Mrk1018 PGC 8029 02:06:16 -00:17:29 10.3 mag Seyfert 1 Galaxy
1ES 0236+610 LS I +61 303 02:40:32 +61:13:42 10.2 mag HMXB (V615 Cas)
1H 0323+342 PGC 2045127 03:24:41 +34:10:46 13.1 mag Blazar
PKS 0716+714 GSC 0368:0899 07:21:54 +71:19:21 14.3 mag Blazar
OJ287 GSC 1400:0230 08:54:49 +20:06:30 14.1 mag Blazar
Mrk110 PGC 26709 09:25:13 +52:17:11 15.2 mag Seyfert 1 Galaxy
Mrk421 PGC 33452 11:04:27 +38:12:31 8.3 mag Blazar
Mrk180 PGC 35899 11:36:26 +70:09:28 14.5 mag Blazar
3C273 PGC 41121 12:29:07 +02:03:09 14.1 mag Blazar
3C279 PGC 2817645 12:56:11 -05:47:22 15.9 mag Quasar
PKS 1510-089 PGC 2828331 15:12:51 +09:06:00 16.5 mag Quasar
PKS 1553+113 GSC 0947:1098 15:55:43 +11:11:24 14.6 mag Blazar
Mrk501 PGC 59214 16:53:52 +39:45:36 13.3 mag Blazar
1ES 1959+650 PGC 2674942 20:00:00 +65:08:55 11.2 mag Blazar
BL Lac 1ES 2200+42.0 22:02:43 +42:16:40 14.7 mag Blazar (prototype)
CTA 102 PGC 2819036 22:32:36 +11:43:51 16.7 mag Quasar (4C 11.69)
3C 454.3 PGC 2819327 22:53:58 +16:08:54 15.2 mag Quasar
1ES 2344+514 QSO B2344+514 23:47:05 +51:42:18 15.5 mag Blazar
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