ARAS Group Additional Optical Spectroscopy of Classical Nova ASASSN-16ig (Sgr 2016 no. 2)
ATel #9379; Lorenzo Franco, Terry Bohlsen (ARAS)
on 16 Aug 2016; 15:21 UT
Distributed as an Instant Email Notice Novae
Credential Certification: S. N. Shore (firstname.lastname@example.org)
Referred to by ATel #: 9613
We supplement ATel #9377 with results for ASASSN-16ig (N Sgr no. 2) from ARAS observers covering the period just before that report and after the Liverpool Telescope observation reported in ATel #9375. Spectra were obtained on Aug. 12.82 (Balzaretto IT, Alpy60, R=560, total exposure time of 4200 sec, 3840-7234A), and Aug. 13.53 (Mirranook Armidale AU, LISA, R=1500, total exposure time 1769 sec, absolute flux calibrated, 3800-7249A). The Aug. 12.8 spectrum was notable in showing strong C II 4267A emission (equiv. width = 100 A) that was not seen in the later spectra. As in earlier reports, strong P Cyg profiles were present on the Balmer (Halpha-Hgamma) lines with vrad(max,blue) = -2000 km/s. Fe II 4924, 5018, and 5169A all displayed broad emission peaks and blueshifted absorption trough at about -1400 km/s; the spectrum was a strong Fe-curtain stage aside from the 4267A line; Na I D may have been detected with a possible P Cyg profile at lower velocity on Aug. 12.8. The Aug. 13.5 spectrum confirmed Na I D with vrad=-1300 and -850 km/s components in absorption (possibly affected by the doublet structure, but agreeing very well with double absorption components on Fe II 4924, 5018, and 5169A and with the Balmer lines). The Halpha/Hbeta/Hgamma ratio (erg/s/cm^2) was 1.6E-11: 1.9E-12: 2.3E-13. The integrated flux (3840-7310A) was 2.4E-10 erg/s/cm^2 (if, e.g., E(B-V)=1.0, 3.6E-9). The C II 7113A was present on both spectra (that along with the C II line point to a CO nova, but this will require monitoring of later stages). Observations are continuing and the spectra are publicly available through the ARAS Database.