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Optical flare observed in the flaring gamma-ray blazar S5 1044+71

ATel #9956; Tapio Pursimo (NOT), Pere Blay (IAC-NOT), John Telting (NOT), and Roopesh Ojha (NASA/GSFC/UMBC)
on 11 Jan 2017; 15:38 UT
Credential Certification: Roopesh Ojha (Roopesh.Ojha@gmail.com)

Subjects: Optical, Gamma Ray, >GeV, AGN, Blazar, Quasar

We report optical photometry of the blazar S5 1044+71, obtained with the 2.56m Nordic Optical Telescope in La Palma, to look for any enhanced optical activity associated with a recent flare in the daily averaged gamma-ray flux (ATel#9928). This flare is evident in the public lightcurve from the Fermi/LAT instrument:https://fermi.gsfc.nasa.gov/FTP/glast/data/lat/catalogs/asp/current/lightcurves/S51044+71_86400.png

These NOT observations were made using the ALFOSC (Andalucia Faint Object Spectrograph and Camera) instrument at the epochs 2017-01-04T06:51, 2017-01-04T19:14 and 2017-01-05T06:09. Standard IRAF data reduction (de-biasing + flat field correction) was carried out and aperture photometry was performed. The brightness was estimated against the star (GSC2.3) N7R8000008 (10 48 43.226 +71 45 38.87 F(=R)=15.14+/-0.45). The std-dev of the zero point for N7R8000008 + three other stars is < 0.02 mag. We find that S5 1044+71 had a R-magnitude = 15.44+/-0.2.

This result suggests that there is significant enhancement in its optical magnitude. For example the Gaia measurement of G=18.56 indicates R about 18.4 (assuming V-R-colour 0.4 and G to V conversion based on Jordi et al. 2010, A&A 523, A48). Other archival magnitudes (obtained using the CDS/Aladin Tool) include NOMAD R-magnitude of 17.490 and GSC2.3 F(=R)-mag=18.31.

Given the nature of this object and its continuing gamma-ray activity we encourage further multi-wavelength coverage. We will continue to monitor this source and report future developments using this and other platforms.