SMARTS O/IR follow-up observations of blazar PMN J2052-5533

ATel #8282; Isler, Jedidah C. (Vanderbilt University); MacPherson, E., Urry, M., Coppi, P. (Yale University)
on 12 Nov 2015; 18:41 UT
Credential Certification: Jedidah Isler (jedidah.isler@vanderbilt.edu)

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As part of our O/IR blazar program, we monitor gamma-ray-bright blazars with the SMARTS 1.3m+ANDICAM instrument in Cerro Tololo, Chile. On 2015 September 23, the Large Area Telescope (LAT) on the Fermi Gamma-ray Space Telescope detected an unusually hard spectrum gamma-ray flare from a source positionally consistent with the blazar PMN J2052-5533 (ATel #8096). Additional Swift/UVOT observations were made on 2015 September 25 & 26 (ATel #8114) which were faint or undetected in the UV and optical.

We obtained relative aperture photometry of this source between 2015 September 28 and 2015 November 11 in B, R and J bands. Consistent with the Swift/UVOT observations, we find the source to have been in an extremely faint O/IR state, despite considerable hardening of the gamma-ray spectrum and 16-fold flux increase above the four year average flux reported in ATel #8096. The O/IR photometry is listed below.

B:
20150928 2457294.65891 18.75
20150929 2457295.64787 18.74
20151001 2457297.64374 17.56
20151003 2457299.64203 19.03
20151006 2457302.61383 18.59
20151007 2457303.60995 18.04
20151028 2457324.51600 19.20
20151102 2457329.57164 19.70
20151109 2457336.54712 19.32

R:
20150928 2457294.66168 18.53
20150929 2457295.65063 18.56
20151001 2457297.64649 17.03
20151003 2457299.64478 18.21
20151006 2457302.61653 18.17
20151007 2457303.61264 17.78
20151028 2457324.51869 18.77
20151102 2457329.57433 19.61
20151109 2457336.54981 19.22

J:
20150929 2457295.64892 17.46
20151001 2457297.64479 15.50
20151003 2457299.64308 16.86
20151007 2457303.61099 17.44
20151028 2457324.51651 17.18

The weather in Cerro Tololo, Chile has ranged from clear with thin clouds to partially overcast over the course of observations. The least reliable data have been removed from the summary above. The optical errors are likely dominated by errors in the USNO photometry. We estimate our errors to be +/- 0.05 mag in the near-infrared. We will continue to monitor this source on a semi-regular basis as part of our ongoing SMARTS monitoring program.

SMARTS Optical/IR Observations of Fermi Blazars