Optical echelle spectroscopy of the classical nova PNVJ17261813-133809354

ATel #16442; Steve Shore (Univ. Pisa, INAF/OATS),Steve Shore (Univ. of Pisa, INAF/OATS), Stéphane Charbonnel (2SPOT), Olivier Garde (2SPOT), Pascal Le Dû (2SPOT), Lionel Mulato (2SPOT), Thomas Petit (2SPOT)
on 13 Feb 2024; 17:24 UT
Distributed as an Instant Email Notice Novae
Credential Certification: S. N. Shore (shore@df.unipi.it)

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We report medium resolution (R~11000) optical echelle spectroscopy of the classical nova PNVJ17261813-133809354, discovered in outburst on 2024 Feb 8.8 UT ATel #16440, CBET #5346) . The nova being been continually monitored by the 2SPOT collaboration using automated telescopes in Chile equipped with an eShel spectrograph covering the spectral interval 3858 - 7616 A. Here we report the results from the spectra obtained on 2024 Feb 11.3 UT (HJD 2460351.847, with an exposure time = 3621 sec), Feb. 12.3 UT (2460352.840, exp. time = 3625 sec), and Feb. 13.3 (2460353.783, exp. time = 6000 sec). The data are pipeline processed with ISIS V6.1.1 software. The continuum, as previously reported, is very heavily reddened. The integrated hydrogen column density N_H ~ 2E21 cm^-2 (LAB survey, Kalberla, P.M.W.et al. 2005, A&A, 440, 775) implying A_V > 1 mag but it is possibly higher than E(B-V) > 1.5 mag using the standard Galactic E(B-V) extinction law to flatten the continuum. The Na I D IS components show EWs of 1.01 and 0.83 A, the ratio is consistent with a high extinction. Our spectra do not extend to the K I lines. The interstellar DIBs at 5783 and 5790 have equivalent widths of 0.53+/-0.02 and 0.16+/-0.02 A, respectively, no others were detected in these spectra. The spectra showed Na I D with a broad absorption extending to about -3000 km/s (Feb. 11) with a maximum depth at -1100 km/s (Feb. 11) and -1600 (Feb. 12); the emission component extended to > +2000 km/s and was about the same strength as the absorption. The latest spectrum shows Na I D with a stronger absorption trough extending to -2800 km/s w(minimum at -1900 km/s). and a similarly extended red wing. There is no terminal edge. The Balmer lines all show strong, very asymmetric profiles that developed rapidly over the three days. The Halpha emission wing extended to -3000 km/s on the first two days days but the profile blue emission edge was at -1200 km/s (Feb 11); it extended to -3500 km/s on Feb 12 with the asymmetry appearing more like a nascent absorption. Hbeta showed a similar profile and development (the red wing is, however, blended with other emission features); Hgamma displayed a red wing extending to about +2000 km/s with a similar profile on the blue wing as the other Balmer lines. None showed a fully developed absorption trough comparable to the Na I lines. The Fe II profiles (e.g., RMT 42) show similar profiles to Hbeta with a red wing extending to -3000 km/s. On Feb. 12 the Fe II RMT 42 profiles showed a blue cutoff of the central emission that coincides in radial velocity with the absorption trough on Na I; except for the depth of the blue component, the emission core and red wing of these profiles are the same. Si II 6347,6370 were not detected, in the first two spectra but may be present on Feb. 12 with a profile similar to the Fe II lines. Neither Ca II K, [O I] 5577,6300,6364 nor the [Ca II] 7291,7323 lines (that might have indicated a different class of transient such as a LNR or ILOT). The metal line profiles are severely blended because of the high ejecta velocities and the source is clearly still very optically thick. The principal changes were the strength of the Balmer and strongest Fe II emission lines and an increase in the strength of the Na I D emission. Spectroscopic monitoring is continuing.

ARAS Database: Novae