Full Text Available
Note: Clicking the button above will open the full text document at the original institutional repository in a new window.
An analysis of beta cephei stars in NGC 3293 and the effects of stellar rotation
Bibliography: p. 243-248.
Saved in:
| Main Author: | |
|---|---|
| Other Authors: | |
| Format: | Thesis |
| Language: | English |
| Published: |
Department of Astronomy
2015
|
| Subjects: | |
| Tags: |
No Tags, Be the first to tag this record!
|
| _version_ | 1867613182512594944 |
|---|---|
| access_status_str | Open Access |
| author | Engelbrecht, Christian Albertus |
| author2 | Balona, Luis |
| author_browse | Balona, Luis Engelbrecht, Christian Albertus |
| author_facet | Balona, Luis Engelbrecht, Christian Albertus |
| author_sort | Engelbrecht, Christian Albertus |
| collection | Thesis |
| description | Bibliography: p. 243-248. |
| format | Thesis |
| id | oai:open.uct.ac.za:11427/15999 |
| institution | University of Cape Town (South Africa) |
| language | eng |
| last_indexed | 2026-06-10T12:32:05.102Z |
| license_str | Not specified — see source repository |
| provenance_str_mv | Harvested via OAI-PMH from UCTD — University of Cape Town Open Access Repository |
| publishDate | 2015 |
| publishDateRange | 2015 |
| publishDateSort | 2015 |
| publisher | Department of Astronomy |
| publisherStr | Department of Astronomy |
| record_format | dspace |
| source_str | UCTD — University of Cape Town Open Access Repository |
| spelling | oai:open.uct.ac.za:11427/15999 An analysis of beta cephei stars in NGC 3293 and the effects of stellar rotation Engelbrecht, Christian Albertus Balona, Luis Warner, Brian Astronomy Bibliography: p. 243-248. An intensive photometric study in the Johnson B band of ten β Cephei stars in the open cluster NGC 3293 is presented. High sampling rates of the stars' light curves allow the identification of many formerly unknown pulsation frequencies in these stars, by means of Fourier periodogram analysis. All of the stars are found to be multiperiodic, with up to five frequencies identified for individual stars. Physical parameters of the stars are determined from previous photometric results in the literature. These parameters are used to make a comparison of the observed frequencies with theoretical predictions, including the effects of rotation. The results imply a preference for first and second overtone quadrupole (l=2) pulsation in these stars, while a weak relationship between stellar mass and pulsation overtone is identified. One of the stars is identified as a member of an eclipsing binary system, only the second β Cephei star to be identified as such. Physical parameters of the system are determined. The effects of rapid rotation (specifically, the distortion of the stellar profile from a perfect sphere) on alternative methods of pulsation mode identification are investigated for a model β Cephei star. Ratios between light and velocity amplitudes show extreme differences between rotationally distorted and undistorted models, but these ratios show high sensitivity to other parameters as well. Thermally broadened spectral line profiles are calculated for the same model, for modes with l = 0 to 4 and equatorial rotation velocities up to 400 km/s. Neglect of rotational distortion is shown to lead to underestimation of true equatorial rotation velocities by as much as 253. This result confirms that observed B stars are probably rotating at break-up velocities. In summary, various aspects of the behaviour of the β Cephei stars in NGC 3293 in particular, and of β Cephei stars in general, including rapid rotators, are illuminated and augmented by this study. 2015-12-28T06:10:08Z 2015-12-28T06:10:08Z 1994 Doctoral Thesis Doctoral PhD http://hdl.handle.net/11427/15999 eng application/pdf Department of Astronomy Faculty of Science University of Cape Town |
| spellingShingle | Astronomy Engelbrecht, Christian Albertus An analysis of beta cephei stars in NGC 3293 and the effects of stellar rotation |
| thesis_degree_str | Doctoral |
| title | An analysis of beta cephei stars in NGC 3293 and the effects of stellar rotation |
| title_full | An analysis of beta cephei stars in NGC 3293 and the effects of stellar rotation |
| title_fullStr | An analysis of beta cephei stars in NGC 3293 and the effects of stellar rotation |
| title_full_unstemmed | An analysis of beta cephei stars in NGC 3293 and the effects of stellar rotation |
| title_short | An analysis of beta cephei stars in NGC 3293 and the effects of stellar rotation |
| title_sort | analysis of beta cephei stars in ngc 3293 and the effects of stellar rotation |
| topic | Astronomy |
| url | http://hdl.handle.net/11427/15999 |
| work_keys_str_mv | AT engelbrechtchristianalbertus ananalysisofbetacepheistarsinngc3293andtheeffectsofstellarrotation AT engelbrechtchristianalbertus analysisofbetacepheistarsinngc3293andtheeffectsofstellarrotation |