On the Symbiotic X-ray Binary Nature of the Star Cgcs 5926
Abstract
We report on multiwavelength (from X-ray to optical) follow up observations of a carbon star CGCS 5926, motivated by the fact that it is positionally coincident with a faint X-ray source of the ROSAT catalog, thus suggesting its possible symbiotic X-ray binary (SyXB) nature. Our optical spectroscopy confirms that this is a carbon star of type C(6,2). This allows us to infer for CGCS 5926 a distance of ∼ 5 kpc. BVR CI C photometry of the star shows variability of ∼ 0.3 mag with a periodicity of 151 days, which we interpret as due to radial pulsations. The source is not detected with the Swift satellite in X-rays down to a 0.3--10 keV luminosity of ∼ 3 × 1032 erg s-1. This nondetection is apparently in contrast with the ROSAT data; however, the present information does not rule out that CGCS 5926 can be a SyXB. This will be settled by more sensitive observations at high energies.
- Publication:
-
Baltic Astronomy
- Pub Date:
- 2012
- DOI:
- 10.1515/astro-2017-0380
- Bibcode:
- 2012BaltA..21..206M
- Keywords:
-
- stars: carbon;
- AGB;
- stars: individual (CGCS 5926);
- stars: oscillations