Ultraviolet observations of two hot stars with infrared excesses from circumstellar dust
Abstract
The five channel ultraviolet grating spectrophotometer aboard the Astronomical Netherlands Satellite (ANS) was used to observe HD 45677 and HD 50138. Both objects are peculiar Be stars exhibiting infrared excesses attributed to circumstellar dust. Neither object has an ultraviolet spectral energy distribution resembling the distributions expected for stars surrounded with normal interstellar dust. The HD 45677 has a relatively strong 0.22 micrometer absorption feature that appears to be of circumstellar origin. The HD 50138 has at most a weak 0.22 micron feature. However, this star does appear to be variable and to have a broad ultraviolet absorption feature peaking in strength at a wavelength longward of 0.22 micrometer. If the day to day and month to month ultraviolet spectral variability of HD 50138 is due to the passage of inhomogeneous clouds of circumstellar dust in front of the star, then the ANS data imply that the local dust peaks in absorption near 0.25 micrometer.
- Publication:
-
NASA STI/Recon Technical Report N
- Pub Date:
- 1977
- Bibcode:
- 1977STIN...7814969S
- Keywords:
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- Astronomical Netherlands Satellite;
- Hot Stars;
- Stellar Envelopes;
- Ultraviolet Spectrophotometers;
- Absorption Spectra;
- Energy Distribution;
- Ultraviolet Spectra;
- Astronomy