The evolutionary state of the red giant star L<sub>2</sub> Puppis
Context. L 2 Puppis (L 2 Pup) is a nearby red giant star and an important object in late-type star research because it has a dust disc and potentially a companion. Aims. L 2 Pup is often called the second-closest asymptotic giant branch (AGB) star to the sun, second only to R Doradus. However, whether the star is indeed on the AGB or the red giant branch (RGB) is questionable. We review its evolutionary state. Methods. We analysed high-resolution optical archive spectra to search for absorption lines of the third dredge-up indicator technetium (Tc) in L 2 Pup. We also compared the star to a sample of well-known AGB stars in terms of luminosity and pulsation properties and placed it in a Gaia -2MASS diagram. Results. L 2 Pup is found to be Tc-poor. Thus, it is not undergoing third dredge-up events. The star is fainter than the RGB tip and fainter than all Tc-rich stars in the comparison sample. L 2 Pup pulsates in the fundamental mode, similar to Mira variables, but its pulsation properties do not allow us to distinguish between the RGB and AGB stages. Conclusions. In conclusion, L 2 Pup could be an RGB or early AGB star, but it is more likely to be an RGB than an AGB star. Our findings are important for a better understanding of the L 2 Pup system and its past and future evolution.
Authors
- S. Uttenthaler (ORCID: https://orcid.org/0000-0002-0055-3815)
Institutions
- TU Wien (AT)
Publication Details
- Journal
- Astronomy and Astrophysics
- Published
- 2024-11-22
- DOI
- https://doi.org/10.1051/0004-6361/202452173
- Citations
- 2
- Primary Topic
- Astronomy and Astrophysical Research
- Type
- article
- Field-Weighted Citation Impact
- 1.01
Funders
- National Science Foundation
- National Aeronautics and Space Administration
- California Institute of Technology
- European Space Agency
- Monash University
- Austrian Science Fund
- Jet Propulsion Laboratory
- University of California, Los Angeles