Strong J-band variability but no radio or X-ray emission from Nova PGIR20eig
ATel #14165; A. Babul (Columbia), K. De (Caltech), J. Sokoloski (Columbia), M. M. Kasliwal (Caltech), K. V. Sokolovsky (MSU), M. Ashley (UNSW), L. Chomiuk (MSU), M. Hankins (Caltech), V. Karambelkar (Caltech), A. Kawash (MSU), R. M. Lau (ISAS/JAXA), J. D. Linford (NRAO), A. Moore (ANU), K. Mukai (NASA/GSFC), E. O. Ofek (Weizmann), M. P. Rupen (NRC), M. Sharma (Columbia), J. Soon (ANU), R. Soria (NAOC), T. Travouillon (ANU)
on 10 Nov 2020; 20:42 UT
Credential Certification: Aliya-Nur Babul (aliya.babul@columbia.edu )
Subjects: Radio, Infra-Red, X-ray, Nova
The near-infrared transient PGIR20eig was discovered on UT 2020-07-13 by the Palomar Gattini-IR survey (De et al. 2020, Moore & Kasliwal 2019) and was confirmed as a nova on UT 2020-08-02 (ATel #13914). The source initially had a J magnitude of 13.35 +/- 0.22 AB mag and rose to a magnitude of 12.55 +/- 0.11 on 2020-07-31 (ATel #13914). On 2020-09-06, the light-curve rose to a J band magnitude of 9.79 +/- 0.09 and began displaying irregular variations with amplitudes of more than half a magnitude. Selected J band magnitudes during the period of variations are listed below:
Date J mag
2020-09-06 9.79 +/- 0.09
2020-09-16 10.53+/- 0.2
2020-10-06 9.99 +/- 0.09
2020-10-20 10.55 +/- 0.2
2020-10-24 10.28+/- 0.14
2020-11-02 10.69 +/- 0.2
We initiated radio monitoring of PGIR20eig with the Karl G. Jansky Very Large Array (VLA). The first observation was conducted on 2020-10-16, which resulted in non-detections at frequencies between 12GHz and 36 GHz. The image RMS at 13.5 GHz was 25 microJy, at 16.5 GHz was 27 microJy, at 29.5GHz was 25 microJy, and at 35 GHz was 62 microJy.
Swift observed PGIR20eig for 1.1ks on 2020-10-25.120. Swift/XRT detected no X-ray source at the position of the transient with an upper limit (Bayesian 90% confidence interval) of 0.002 ct/s, corresponding to a flux ~1e-13 erg/cm2/s. Assuming the photon index of 1.7 and hydrogen column density of 3x10^20 cm^-2 we obtain the unabsorbed 0.3-10.0 keV flux limit of 1x10^-13 ergs/cm^2/s. Swift/UVOT measured the V band magnitude of the nova as 15.64 +/-0.04 (AB system).
Further follow-up observations are encouraged.
