We present an analysis of the red giant component of the recurrent nova V3890 Sgr, using data obtained before and after its 2019 eruption. Its effective temperature is Teff = 3050 ± 200 K for log g = 0.7, although there are modest changes in Teff. There is an overabundance of both carbon (0.20 ± 0.05 dex) and sodium (1.0 ± 0.3 dex) relative to their solar values, possibly the result of ejecta from the 1990 nova eruption being entrained into the red giant photosphere. We find 12C/13C =25 ± 2, a value similar to that found in red giants in other recurrent novae. The interpretation of the quiescent spectrum in the 5-38 μm region requires the presence of photospheric SiO absorption and cool (∼400 K) dust in the red giant environment. The spectrum in the region of the Na i D lines is complex, and includes at least six interstellar components, together with likely evidence for interaction between ejecta from the 2019 eruption and material accumulated in the plane of the binary. Three recurrent novae with giant secondaries have been shown to have environments with different dust content, but photospheres with similar 12C/13C ratios. The SiO fundamental bands most likely have a photospheric origin in the all three stars.
|Original language||English (US)|
|Number of pages||13|
|Journal||Monthly Notices of the Royal Astronomical Society|
|State||Published - Dec 1 2022|
Bibliographical noteFunding Information:
This study was funded as part of the routine financing programme for institutes of the National Academy of Sciences of Ukraine. YP gratefully acknowledges the hospitality of the Nicolaus Copernicus Astronomical Center, Toruń, and support from grant 2017/27/B/ST9/01128 financed by the Polish National Science Center, while this work was being completed. DPKB is supported by a CSIR Emeritus Scientist grant-in-aid and is being hosted by the Physical Research Laboratory, Ahmedabad. RDG was supported by the National Aeronautics and Space Administration (NASA) and the United States Air Force (USAF). FMW acknowledges support of the US taxpayers through NSF grant 1611443.
© 2022 The Author(s).
- circumstellar matter
- infrared: stars
- novae, cataclysmic variables
- stars: abundances
- stars: AGB and post-AGB
- tars: individual: V3890 Sgr