Magellan/FIRE spectroscopy of AT2023tow: Confirmation of a young, highly reddened Galactic Fe II nova with CO emission
ATel #16255; R. Soria (NAOC), K. De (MIT), D. Durovcikova (MIT), R. Simcoe (MIT), V. Karambelkar (Caltech), M. Hankins (ATU), M. M. Kasliwal (Caltech), J. Sokoloski (Columbia), M. Ashley (UNSW), A. Babul (Columbia), R. M. Lau (NOIRLab), A. Moore (ANU), E. O. Ofek (Weizmann), M. Sharma (Columbia), J. Soon (ANU), T. Travouillon (ANU)
on 26 Sep 2023; 21:18 UT
Distributed as an Instant Email Notice Novae
Credential Certification: Kishalay De (kde1@mit.edu)
Subjects: Infra-Red, Optical, Cataclysmic Variable, Nova, Transient
Referred to by ATel #: 16259
We report spectroscopic classification of AT 2023tow,, a bright infrared transient near the Galactic plane detected by the Palomar Gattini-IR, ZTF and Gaia surveys. The source was first detected in Palomar Gattini-IR on UT 2023-09-13 at a flux of J = 8.77 +/- 0.01 mag, at J2000 coordinates
RA = 18:41:41.50
Dec = -07:09:34.49
The source was also previously detected by ZTF on UT 2023-09-11 at g = 17.17 +/- 0.06 mag, and reported to the Transient Name Server by the Gaia survey on 2023-09-25. There is no source at this position in archival 2MASS images. The corresponding Galactic latitude is -1.1 degrees, with a total integrated line of sight extinction of AV ~ 8.5 mag.
On UT 2023-09-26, we obtained a near-infrared 0.9 - 2.5 micron spectrum with our Target of Opportunity program on the Magellan/FIRE instrument. The reduced spectrum shows broad emission lines of H I, He I and O I with P-Cygni profiles and absorption velocities of ~ 900 km/s. We clearly identify broad emission lines of C I, seen in Fe-II type novae (Banerjee & Ashok 2012). Overall, the spectrum and photometric colors are consistent with a young, highly reddened Fe II nova. We clearly detect strong emission in the CO band head in K band, suggesting that the nova is likely to form dust. We encourage continued photometric and spectroscopic observations of the source.
