Rapid line sharpening and ionization increase in V3890 Sgr
ATel #13081; U. Munari (INAF Padova) and F. M. Walter (Stony Brook University)
on 5 Sep 2019; 20:06 UT
Credential Certification: U. Munari (ulisse.munari@oapd.inaf.it)
Subjects: Optical, Cataclysmic Variable, Nova
The recurrent nova V3890 Sgr has recently gone into outburst for the third
time. Reports about optical spectra have appeared in ATel #13047, #13059,
#13060, #13062, #13069, and Swift X-ray and UV data in ATel #13050, #13072.
We are continuing the daily spectroscopic monitoring of the eruption of
V3890 Sgr with Asiago 1.22m and SMARTS 1.5m telescopes. The spectral
evolution proceeds at a fast pace.
On our latest spectrum for Sept 5.77 UT HeI and OI lines have sharpen to
FWHM~490 and 380 km/s, respectively, with no broad pedestal underneath,
while Balmer lines are characterized by a two-component profile with a
FWHM~830 km/s Gaussian on top of a broader FWHM~4200 km/s Gaussian base
(with FWZI~8000 km/s). For Halpha, the integrated flux of narrow and broad
components are 3.70x10(-11) and 6.84x10(-11) erg/cm2 s Ang, respectively (all
fluxes below are given in these same units).
HeII is rapidly gaining in strength, and on Sept 5.77 UT it has FWHM~520 km/s,
and an integrated flux 5.29x10(-12), only fractionally smaller than the
flux of the narrow component of Hbeta at 7.07x10(-12). At the same time,
low ionization FeII line remains present with all major multiplets fully
formed (like 27, 37, 38, 40, 42, 46, 48, 49, 74, etc.). For reference FeII
multiplet 42 at 5169 Ang has an integrated flux 1.43x10(-12). It is not yet
possible to infer if any [FeX] 6375 is already present because of still
strong SiII doublet at 6347, 6372 and FeII at 6384.
The Bowen excitation chain for NIII 4642 is clearly in place as indicated by
the presence of OIII at 3429, 3445. No [NeV] lines have yet emerged as of Sept
5.77 UT, with other high ionization forbidden lines remaining rather weak (like
[FeVII] with an integrated flux of 1.32x10(-13).
