Near Infrared spectroscopy of the recurrent nova M31N 2008-12a
ATel #16968; D. P. K. Banerjee (Physical Research Laboratory, India), T. R. Geballe (NOIRlab/Gemini Observatory), A. Evans (Keele University), C. E. Woodward (University of Minnesota), S. Starrfield (Arizona State University)
on 8 Jan 2025; 22:31 UT
Credential Certification: Dipankar P.K. Banerjee (dpkb12345@gmail.com)
Subjects: Infra-Red, Nova
We obtained a near-infrared (0.82-2.52 micron)spectrum of the 2024 eruption of the recurrent nova M31N 2008-12a (see Atel #16942) on 2024 December 20 from 6.95 to 8.48 hrs UTC, some 6.3 days after the eruption. The data were obtained with the facility spectrometer GNIRS on the 8m Gemini North telescope, with the instrument in its cross-dispersed mode, using the 32 l/mm grating and a 1 arcsec slit (giving spectral resolving power on the nova of ~1000 ) and a 4800s exposure time. The HeI triplet at 1.0833 micron is clearly present, with a deconvolved FWHM of ~1500 km s^-1, a line peak-to-continuum ratio of about 7, and an estimated flux of 4 x 10^-19 W m^-2. Also present are weak features on its blue and red wings; we tentatively identify the shorter wavelength emission component with the [Fe XIII] 1.07498 micron coronal line. The red wing is probably not H I Pa gamma, as the H I Pa beta line at 1.28 micron was not detected. The emission lines lie on a weak continuum that rises toward the blue end of the spectrum. Analysis of a second spectrum, obtained on 2024 December 23.3050 UTC (about 10.3d after discovery), is currently under way, but it is clear that the He I 1.0833 micron line had faded below the detection limit by this time.
The data were obtained during Director's Discretionary Time for this program (GN-2024B-DD-106).
