SOAR/MeerLICHT classification of the Galactic plane transient AT2022jrn as a microlensing event
ATel #15394; K. De (MIT), P. Groot (Radboud, UCT, SAAO), P. Vreeswijk (Radboud), C. Johnston (Radboud)
on 23 May 2022; 17:19 UT
Credential Certification: Kishalay De (kde1@mit.edu)
Subjects: Infra-Red, Optical, Microlensing Event, Transient
The transient AT 2022jrn was discovered on UT 2022-05-10 by MeerLICHT (Groot & Vreeswijk; TNS #146827) as a reddened Galactic plane transient. On UT 2022-05-12, we obtained a near-infrared (1.0 - 2.5 micron) spectrum of the transient with TripleSpec on SOAR. The reduced spectrum shows a red continuum peaking in H-band with strong absorption features Si I, Na I and Ca I in H and K bands, and of the CO-band heads in K band. No emission features suggestive of a nova / dwarf nova outburst are detected. Together with the lack of TiO and VO bands in J band, the spectrum is consistent with a reddened K3-type star. Photometric coverage from MeerLICHT after the discovery shows the transient to have smoothly faded from i~14.6 mag to i~17.5 mag in ~ 7 days.
Overall, the photometry and spectrum suggest that AT 2022jrn is a reddened microlensing event in the direction of the Galactic bulge. We thank the SOAR staff for assistance with these observations.
