Time resolved spectroscopy of KPD1930+2752
| dc.creator | Geier, S. | |
| dc.creator | Heber, U. | |
| dc.creator | Przybilla, N. | |
| dc.creator | Kudritzki, R. P. | |
| dc.date | 2005-10-28 | |
| dc.date.accessioned | 2026-07-07T06:44:03Z | |
| dc.date.available | 2026-07-07T06:44:03Z | |
| dc.description | We present the analysis of 200 high-resolution and 150 low-resolution spectra of the pulsating subdwarf close binary KPD 1930+2752 obtained with the Keck and the Calar Alto 2.2 m telescopes. Using metal-rich, line blanketed LTE model atmospheres the atmospheric parameters T_{eff} = 35500 +/- 500 K, log g = 5.56 +/- 0.05 and log n(He)/n(H) = -1.48 +/- 0.02 were derived. The radial velocity curve was measured and combined with all available published and unpublished radial velocity data in order to get results of high accuracy (K = 341 +/- 1 km/s, P = 0.0950933 +/- 0.0000015 d). For the first time we measured the projected rotational velocity. The preliminary result is v_{rot}sin{i} = 97 +/- 9 km/s. Since the rotation of the sdB star is very likely tidally locked to the orbit, we can constrain the inclination of the system. Assuming the companion to be a white dwarf, the mass of the sdB is limited from 0.44M_{sun} to 0.63M_{sun} and the total mass range of the system is 1.3 M_{sun} to 2.0 M_{sun}. It is very likely that the total mass exceeds the Chandrasekhar limit. Hence KPD 1930+2752 is a candidate for a progenitor of a Type Ia supernova. According to the derived limits for the inclination angle, eclipses are likely to occur. | |
| dc.description | 8 pages, 5 figures, to appear in Proc. of the Second Meeting on Hot Subdwarf Stars an Related Objects | |
| dc.identifier | https://arxiv.org/abs/astro-ph/0510795 | |
| dc.identifier | http://arxiv.org/abs/astro-ph/0510795 | |
| dc.identifier.uri | http://salesiana.dossiersoluciones.com/handle/123456789/102649 | |
| dc.subject | Astrophysics | |
| dc.title | Time resolved spectroscopy of KPD1930+2752 | |
| dc.type | text |