Confirmation of TCP J18102829-2729590 in Sagittarius as a classical nova in the optically thick stage

I report optical spectroscopic followup on the nova candidate TCP J18102829-2729590 (CBAT 2016 10 20.383). A low resolution spectrum was obtained with an Alpy600 spectrograph and Atik414 CCD (R=540) from Shenton Park, Australia with 600 sec exposure time and S/N ratio of about 100 on 2016 Oct 10 at 20.4 UT covering 3900-7300A. Based on the line profiles and velocities, the object is a classical nova in the early optically thick stag. The Balmer series showed P Cyg profiles with a maximum absorption velocity of -1500 km/s and an ejecta-like profile with no distinct blue edge; H-alpha and H-beta showed the same absorption, H-gamma was slightly lower in velocity, and H-delta was the last of the series. The HWZI of the redshifted wing was similar in velocity. The Fe II 4923, 5018, 5169 (RMT42) lines all showed P Cyg profiles with maximum absorption velocities similar to the Balmer lines with a ratio of absorption to emission equivalent width of about 0.4. Neither He I, C II, [N II] nor [O I] lines were present. The Ca II H and K lines showed absorption, as did Na I D but at a low velocity (vrad(min) approx. -170 km/s) and may be dominated by an unresolved interstellar contribution with possible weak redshifted emission on Na I D. Spectroscopic monitoring is continuing. The spectra will continue to be posted for open access at the Astronomical Ring for Access to Spectroscopy (ARAS) database.