Sakurai's Object: characterizing the near-infrared CO ejecta between 2003 and 2007
Abstract
We present observations of Sakurai's Object obtained at 1-5 μm between 2003 and 2007. By fitting a radiative transfer model to an echelle spectrum of CO fundamental absorption features around 4.7μm, we determine the excitation conditions in the line-forming region. We find 12C/13C = 3.5+2.0-1.5, consistent with CO originating in ejecta processed by the very late thermal pulse, rather than in the pre-existing planetary nebula. We demonstrate the existence of 2.2 × 10-6 <= MCO <= 2.7 × 10-6Msolar of CO ejecta outside the dust, forming a high-velocity wind of 500 +/- 80 km s-1. We find evidence for significant weakening of the CO band and cooling of the dust around the central star between 2003 and 2005. The gas and dust temperatures are implausibly high for stellar radiation to be the sole contributor.
- Publication:
-
Monthly Notices of the Royal Astronomical Society
- Pub Date:
- February 2009
- DOI:
- 10.1111/j.1365-2966.2008.14135.x
- arXiv:
- arXiv:0810.4556
- Bibcode:
- 2009MNRAS.393..108W
- Keywords:
-
- stars: abundances;
- stars: AGB and post-AGB;
- circumstellar matter;
- stars: individual: V4334 Sgr;
- stars: individual: Sakurai's Object;
- stars: winds;
- outflows;
- Astrophysics
- E-Print:
- 6 pages, 3 figures, 2 tables