Spectroscopic observations of the latest outburst of Nova LMC 1968
ATel #16761; Steven N. Shore (Univ. Pisa; INAF/OATS),Stephane Charbonnel, Olivier Garde, Pascal Le Du, Lionel Mulato, Thomas Petit (2SPOT, ARAS Group)
on 9 Aug 2024; 02:00 UT
Distributed as an Instant Email Notice Transients
Credential Certification: S. N. Shore (shore@df.unipi.it)
Subjects: Nova, Transient
A 6000 sec spectrum was obtained on 2024 Aug. 5.3 UT (day 4.7) at a resolution of about 570 (Alpy600) and minimum S/N ratio of about 15 (for He II 5411 A) covering 3600-7800 A by the 2SPOT consortium. The spectrum is quite simple, only emission lines were detected at this resolution. He I 5876 A may be present but extremely weak, while neither He I 6678 A nor 7065A was visible. He II 4686 dominates the spectrum, with a ratio He II 4686/Hbeta= 2.1+/-0.1; the Balmer decrement (corrected for E(B-V) = 0.15) is 3.8:1.0:0.9:0.7. The Halpha profile shows broad wings extending to +/-5000 km/s with a narrower central portion in the interval -900 to 1780 km/s and no evidence on an absorption component on any lines. The He II 4686 profile is virtually the same as Halpha, there is a hint of the N III 4640A line but it is very weak relative to He II. No metal lines are present. We note that the profiles are different from Fig. 15 in Kuin et al. (2020, MNRAS, 491, 655), suggesting that the ejecta structure may change among outbursts; the profiles are more similar to those in the 1991 IUE sequence on the same day. Observations began as soon as the weather cleared at the 2SPOT site in Chile and will continue, further spectroscopy at higher resolution is urged.
ARAS Spectral Database Novae
