Transient nature of J195754+353513

TL;DR

This study reports the discovery of a transient radio source, J195754+353513, exhibiting significant variability over twenty years, with potential near-infrared counterpart, but its exact nature remains uncertain.

Contribution

First detailed analysis of the transient behavior of J195754+353513 using two decades of archival data, revealing its variability and polarization properties.

Findings

Source varies from <0.3 mJy to 201 mJy

Detected intra-day variability with flux rising from ~20 mJy to ~180 mJy in 700 seconds

Circular polarization detected with V/I between 0.15 and 0.25

Abstract

We have searched for transient and/or variable radio sources in the field of Galactic micro-quasar Cygnus X-1 in 1.4 GHz (L band) using data from the Karl G. Jansky Very Large Array (JVLA). We used twenty years of data between 1983 and 2003. We found a source J195754+353513 showing transient behavior. The source was also mentioned earlier in NVSS and WENSS catalog but its transient nature was not reported earlier. The source is located 23.8 arcminutes far from Cygnus X-1. It is detected many times during the span of our study and it varied between less than 0.3 mJy to 201 mJy. J195754+353513 also showed high intra-day variability. In one occasion, the source rose from ~20 mJy to ~180 mJy 700 second. For limited number of cases circularly polarized emission could be detected from the source with V/I vary between 0.15 to 0.25. 2MASS J19575420+3535152 may be the near-infrared counterpart of the source. We compared the properties of the source with other Galactic transient sources having similar properties. The nature of the source is still unknown. We speculate on its possible nature.