The radio and optical counterpart of the new Fermi LAT flaring source J0109+6134

ATel #2421; J. M. Paredes (University of Barcelona), J. Martí (University of Jaen), M. Peracaula (University of Girona)
on 4 Feb 2010; 18:37 UT
Credential Certification: Josep Martí (jmarti@ujaen.es)

Tweet

Following the recent ATELs #2414, #2416 and #2420 concerning the Fermi-LAT, AGILE and Swift/XRT consistent detections of the new gamma-ray flaring source J0109+6134, we wish to remind that the proposed radio counterpart (VCS2 J0109+6133/GT 0106+613) was extensively observed nearly two decades ago by different authors in the context of the GT catalogue of Galactic Plane radio sources (Taylor and Gregory 1983, AJ, 88, 1784; Gregory and Taylor 1986, AJ 92, 371). From these historical observations, GT 0106+613 appeared compact and displaying both long-term and short-term radio variability. In particular, day to day variations of 10-20 mJy and yearly changes as high as 200 mJy were reported at 6 cm (see Duric and Gregory 1988, ApJ 95, 1149). The optical counterpart of GT 0106+613 was identified as a faint stellar-like object with magnitude I=19.4 located at (J2000) R.A. 01h09m46.33s DEC +61d33'29.1", whose offset from the GT radio position was within one arc-second (Paredes, Marti, Jordi et al. 1993, A&ASS 102, 381). This optical object is consistent in position with all present day detections including the most accurate Swift/XRT error box. Its galactic/extragalactic nature could not be established from these historic observations. Spectroscopy with modern large telescopes is strongly encouraged.