A GHRS/HST Spectral Atlas of Sirius-A
Abstract
The Goddard High Resolution Spectrograph (GHRS) onboard the Hubble Space Telescope has been used to obtain a spectral atlas, covering the wavelength range 1270 - 3200 Angstroms , of the bright star Sirius-A (A1 V). The use of the GHRS first-order gratings provides spectral resolutions between R = 20000 - 35000; however, the rotational velocity (v sin i = 16 km sec(-1) ) limits the spectral resolution. The signal-to-noise ratio over most of the spectrum is approximately 200 by photon statistics. The data are being used to understand the ultraviolet line opacity in warm stars. As a result of this work a new model atmosphere for Sirius will be determined, along with corrections to its bolometric correction and elemental abundances. The spectrum also allows us to test and improve current atomic models. A by-product of our work will be more accurate wavelengths and oscillator strengths for the second spectra of the iron-peak elements that will serve as templates for studying the ultraviolet spectra, obtained at lower spectral resolutions, of other warm stars.
- Publication:
-
American Astronomical Society Meeting Abstracts
- Pub Date:
- December 1993
- Bibcode:
- 1993AAS...183.1806W