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Theoretical studies of mass loss and shock phenomena in cool star envelopes
| Content Provider | NASA Technical Reports Server (NTRS) |
|---|---|
| Author | Hartmann, Lee |
| Copyright Year | 1988 |
| Description | To show the difficulty of producing the blue-shifted emission of (O I) and (S II) from T Tauri stars directly in the stellar wind, an element of gas in a radially expanding stellar wind was followed as it cooled and recombined. Results indicate that T Tauri winds must be heated at large distances from the star to produce the (S II) emission. A shock between the wind and the disk is an attractive mechanism to produce this heating. When the theory is applied to a simple disk model, a number of predictions and implications are evident, for example, that some T Tauri stars eject mass near the equatorial plane. In a second study, spectral energy distributions of T Tauri stars were analyzed to place limits on the amount of accretion which might occur during the early phase of stellar evolution. The best match to H-alpha line profiles is for models in which the turbulent velocity dominates close to the star, while expansion dominates farther out. Such a model predicts, for instance, that a mass loss rate of 1/10,000,000 solar masses per year is required to account for the blue-shifted Na I absorption of some objects. |
| File Size | 802525 |
| Page Count | 20 |
| File Format | |
| Alternate Webpage(s) | http://archive.org/details/NASA_NTRS_Archive_19880007233 |
| Archival Resource Key | ark:/13960/t57d7s33f |
| Language | English |
| Publisher Date | 1988-02-01 |
| Access Restriction | Open |
| Subject Keyword | Astronomy Stellar Spectra Stellar Winds Oxygen Stellar Mass Ejection Spectral Energy Distribution H Alpha Line Stellar Radiation Infrared Spectra Stellar Models Far Infrared Radiation Stellar Envelopes Shock Heating Stellar Mass Accretion Sodium Stellar Mass Emission Spectra Spectrum Analysis T Tauri Stars Sulfur Plasma Heating Ntrs Nasa Technical Reports Server (ntrs) Nasa Technical Reports Server Aerodynamics Aircraft Aerospace Engineering Aerospace Aeronautic Space Science |
| Content Type | Text |
| Resource Type | Technical Report |
