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Hydrodynamic models of a cepheid atmosphere. ph.d. thesis - maryland univ., college park
| Content Provider | NASA Technical Reports Server (NTRS) |
|---|---|
| Author | Karp, A. H. |
| Copyright Year | 1974 |
| Description | A method for including the solution of the transfer equation in a standard Henyey type hydrodynamic code was developed. This modified Henyey method was used in an implicit hydrodynamic code to compute deep envelope models of a classical Cepheid with a period of 12(d) including radiative transfer effects in the optically thin zones. It was found that the velocity gradients in the atmosphere are not responsible for the large microturbulent velocities observed in Cepheids but may be responsible for the occurrence of supersonic microturbulence. It was found that the splitting of the cores of the strong lines is due to shock induced temperature inversions in the line forming region. The adopted light, color, and velocity curves were used to study three methods frequently used to determine the mean radii of Cepheids. It is concluded that an accuracy of 10% is possible only if high quality observations are used. |
| File Size | 4666360 |
| Page Count | 193 |
| File Format | |
| Alternate Webpage(s) | http://archive.org/details/NASA_NTRS_Archive_19750007448 |
| Archival Resource Key | ark:/13960/t5hb3ws0g |
| Language | English |
| Publisher Date | 1974-11-01 |
| Access Restriction | Open |
| Subject Keyword | Astronomy Stellar Atmospheres Energy Spectra Atmospheric Models Turbulence Effects Hydrodynamic Equations Line Spectra Cepheid Variables Cepheus Constellation Atmospheric Optics Ntrs Nasa Technical Reports Server (ntrs) Nasa Technical Reports Server Aerodynamics Aircraft Aerospace Engineering Aerospace Aeronautic Space Science |
| Content Type | Text |
| Resource Type | Thesis |
