Palomar Gattini-IR discovery and classification of a new highly reddened Galactic nova PGIR22akgylf in the active TESS field

ATel #15587; K. De (MIT), R. Soria (NAOC), M. Badenas Agusti (MIT), M. Kong (Caltech), V. Karambelkar (Caltech), M. Hankins (ATU), M. M. Kasliwal (Caltech), J. Sokoloski (Columbia), M. Ashley (UNSW), A. Babul (Columbia), R. M. Lau (ISAS/JAXA), A. Moore (ANU), E. O. Ofek (Weizmann), M. Sharma (Columbia), R. Simcoe (MIT), J. Soon (ANU), R. Soria (NAOC), T. Travouillon (ANU), A. Vanderburg (MIT) on behalf of the Palomar Gattini-IR
on 3 Sep 2022; 11:41 UT
Distributed as an Instant Email Notice Novae
Credential Certification: Kishalay De (kde1@mit.edu)

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We report the discovery and spectroscopic classification of the highly reddened transient PGIR22akgylf / AT 2022sfe in the ongoing TESS Sector 55. The transient was identified in regular survey operations of Palomar Gattini-IR (De et al. 2020; Moore & Kasliwal 2019).

PGIR22akgylf was first detected as a transient source on UT 2022-08-16 at a brightness of J = 13.4 +/- 0.3 mag, at J2000 coordinates
RA = 20:00:29.26
Dec = +34:53:09.14
Corresponding to a Galactic latitude of 2.5 degrees. The source has subsequently brightened to J = 10.4 +/- 0.01 mag on UT 2022-09-01. There is no source at this position in archival 2MASS images. The source is also detected in public data from the Zwicky Transient Facility (Bellm et al 2019.; Graham et al. 2019) as ZTF22abazrjk rising to a magnitude of g ~ 18 mag, suggesting it is highly reddened. The integrated line of sight extinction along the direction is ~ 8 mag in V band and ~ 2.1 mag in J band.

On UT 2022-08-29, we triggered our Target of Opportunity program on the Magellan Clay telescope (PI: De) to obtain a high resolution (R ~ 40000) spectrum of the transient source (0.49 - 0.96 micron). The spectrum shows strong and broad emission lines of the Balmer series, the Paschen series, He I (5876, 6678, 7066, 7281 Angstrom), N II and Ca II. The H alpha line shows a P-Cygni profile with a weak absorption component at a velocity of ~ 1050 km/s. Overall, the photometric and spectroscopic characteristics are consistent with a highly reddened nova in the active TESS field.

Further follow-up is underway and encourage rapid multi-wavelength follow-up observations of this active nova in the TESS field.