Strömgren color-temperature relations for cool stars
| dc.contributor.author | Clem, James Lewis | en_US |
| dc.date.accessioned | 2024-08-13T17:54:13Z | |
| dc.date.available | 2024-08-13T17:54:13Z | |
| dc.date.copyright | 2001 | en_US |
| dc.date.issued | 2001 | |
| dc.degree.department | Department of Physics and Astronomy | |
| dc.degree.level | Master of Science M.Sc. | en |
| dc.description.abstract | Color temperature relations and bolometric corrections are commonly employed not only to infer the physical properties of a star from its photometric color indices, but more importantly to translate stellar evolutionary tracks and isochrones from the theoretical temperature-luminosity plane to the observational color-magnitude plane. The current work discusses the efforts to develop a new and extensive grid of synthetic Stromgren colors applicable to cool, low mass stars (i.e., those having 3000 K ::; Terr::; 8000 K, - 0.5::; logg ::; 5.0, and -3. 0 ::; [Fe/HJ::; +0 . 5) . These purely theoretical colors, based on the latest versions of the MARCS model atmosphere and SSG spectral synthesis codes, are placed onto the observational systems by applying color calibrations derived from the uvby photometry of field stars having accurate H ipparcos parallaxes and effective temperatures determined using the infrared flux method. The resultant color transformations are able to reproduce the observed colors of the classic Population II subdwarfs quite satisfactorily, as well as yield a very good fit of a 4 Gyr isochrone, whose T eff scale is normalized to the Sun, to the observational color-magnitude diagram of the open cluster M 67. To supplement this investigation, recent photometric observations in the uvby filter system of the open clusters NGC 188 and NGC 6819 were obtained to further constrain the accuracy of the new Stromgren color-temperature relations for solar metallicities. Moreover, when the latest theoretical isochrones of Bergbusch & VandenBerg (2001) are transformed to the various Stromgren color planes, they provide superb fits to the CMDs of such globular clusters as M 92, M 13, NGC 288, and 4 7 Tue when reasonable estimates for the basic cluster parameters (i.e. distance, reddening, and metallicity) are assumed. | |
| dc.format.extent | 124 pages | |
| dc.identifier.uri | https://hdl.handle.net/1828/17478 | |
| dc.rights | Available to the World Wide Web | en_US |
| dc.title | Strömgren color-temperature relations for cool stars | en_US |
| dc.type | Thesis | en_US |
Files
Original bundle
1 - 1 of 1
Loading...
- Name:
- CLEM_James_Lewis_MSc_2001_1213490.pdf
- Size:
- 19.47 MB
- Format:
- Adobe Portable Document Format