Optical and Infrared Spectroscopy of Nova Ophiuchi 2018 No.2
ATel #11670; R. J. Rudy, J. C. Mauerhan, R. W. Russell, J. P. Subasavage, S. J. Wiktorowicz, D. L. Kim (Aerospace Corporation.), M. L. Sitko (U. of Cincinnati)
on 23 May 2018; 21:24 UT
Credential Certification: Richard Rudy (richard.j.rudy@aero.org)
Subjects: Infra-Red, Optical, Nova
Over a two week period coming approximately two months after outburst, Nova Ophiuchi 2018, No.2 (CBET 4492) was observed spectroscopically using instruments from three different facilities: 2018 May 6, using the Spex instrument at the Infrared Telescope Facility (0.7-2.5 microns); 2018 May 14, using the Broadband Array Spectrograph System on the 3.6 meter Advanced Electro-Optical Systems telescope (3-13 microns); 2018 May 19, with the VNIRIS spectrograph on the Aerospace Corporation's one meter telescope (0.47-2.5 microns). No significant changes were seen between the May 6 and May 19 observations. Excitation of the emission line gas was fairly low during this period with C I, N I, O I lines were still present in the spectrum and the He I lines just emerging. The strongest emission features were H-alpha and the O I lines at 0.8446 and 1.1287 microns. The latter transitions are excited by Lyman Beta fluorescence and their relative strengths, together with the O I transition at 1.3165 microns, indicate a reddening value of E(B-V) = 0.55 +- 0.15. This extinction is interstellar in origin as there was no indication of dust present in the nova ejecta. Line widths were approximately 1400 km/sec as measured from their full width half maxima.
