Spectroscopy of Nova Cas 2020 (TCP J00114297+6611190)
ATel #13998; G. M. Hamed (Univ. Istanbul, National Research Institute of Astronomy and Geophysics-Cairo), H. H. Esenoglu (Univ. Istanbul), A. I. Galeev (Kazan Federal University, Academy of Sciences of Tatarstan)
on 8 Sep 2020; 12:37 UT
Credential Certification: Hasan H. Esenoglu (esenoglu@istanbul.edu.tr)
We report low and medium spectroscopic observations of the Nova Cas 2020 using the TUG faint object Spectrograph and Camera (TFOSC) mounted on the 1.5 m mounted on the Russia Turkey Telescope (RTT150) of the TUBITAK National Observatory (TUG) in Bakirlitepe, Antalya, Turkey. We used three grisms covering the spectral ranges 4200-6650, 6190-8190 and 3650-8740 Å with spectral resolutions of 1331, 2189 and 749 respectively. We obtained spectra with exposure times of 600, 900, and 1200 sec. The observations were made on August 10.9, 11.7 and 12.14. Most of the Balmer series lines were in absorption except for H α which showed a prominent P Cygni profile. Hδ was observed in absorption for the first two nights but it could not be seen on Aug. 12.14. Hγ showed an absorption profile on Aug. 10 .9and 11.7. On Aug. 12.14 there was a strong emission line centred at 3451 Å with an equivalent width (EW in Å) of -6.017. On Aug. 10.9 Hβ had an EW of 1.9. On Aug. 11.7 it increased to 3 then the line transitioned to emission on Aug. 12.14 with the EW of -11.06. Hα showed a strong P Cygni profile where the absorption component had an EW of 2.2 and the emission component's EW was about 4.5. On Aug 11.7, the EW of the absorption component increased to about 3.0 and the EW of the emission component became 3.5. On Aug 12.14, the absorption component disappeared and the EW of the emission line became 22.4. The He I 5876 and He II 4868 lines were absent for the spectra taken on Aug. 10.9 and 11.7 but the He I 5876 line was visible on Aug. 12.14. The O I 7772 line showed a P Cygni profile. The Na I 5896 interstellar absorption line showed one strong component. The Ca II doublet 3934, 3968 was strong and blueshifted. The N II 5682 line reported in ATel #13905 was absent in our spectra. The Blue continuum decreased from Aug 10.9 to Aug 11.7 by about one order of magnitude.
The link below contains a table showing the main parameters of some of the most prominent lines. The flux was not corrected for Interstellar extinction and the integrated absolute in erg/cm2 s. Equivalent width values are shown with a plus sign for absorption component and with a minus sign for emission ones. However, the fluxes are specified as the opposite sign of EWs. The link also shows a plot showing the transition H α line from P Cygni to pure emission.
We thank TUBITAK National Observatory for a partial support in using RTT150 with project numbers 1628 and 949. GMH also thanks Turkey Scholarships Postdoctoral Research Fellowship for the financial support. The work of AIG was carried out at the expense of a grant allocated by the KFU (project 0671-2020-0052 of the state task 075-00216-20-05).
Table and H alpha plot
