The pti carbon star angular size survey: effective temperatures and non-sphericity
Article
Article Title | The pti carbon star angular size survey: effective temperatures and non-sphericity |
---|---|
ERA Journal ID | 1057 |
Article Category | Article |
Authors | van Belle, Gerard T. (Author), Paladini, Claudia (Author), Aringer, Bernhard (Author), Hron, Josef (Author) and Ciardi, David (Author) |
Journal Title | The Astrophysical Journal: an international review of astronomy and astronomical physics |
Journal Citation | 775 (1), pp. 45-63 |
Article Number | 45 |
Number of Pages | 19 |
Year | 2013 |
Publisher | IOP Publishing |
Place of Publication | United States |
ISSN | 0004-637X |
1538-4357 | |
Digital Object Identifier (DOI) | https://doi.org/10.1088/0004-637X/775/1/45 |
Web Address (URL) | http://iopscience.iop.org/article/10.1088/0004-637X/775/1/45 |
Abstract | We report new interferometric angular diameter observations of 41 carbon stars observed with the Palomar Testbed Interferometer. Two of these stars are CH carbon stars and represent the first such measurements of this subtype. Of these, 39 have Yamashita spectral classes and are of sufficiently high quality that we can determine the dependence of effective temperature on spectral type. We find that there is a tendency for the effective temperature to increase with increasing temperature index by 120 K per step, starting at T EFF ≃ 2500 K for C3, y, although there is a large amount of scatter in this relationship. Overall, the median effective temperature of the carbon star sample is 2800 ± 270 K and the median linear radius is 360 ± 100 R. We also find agreement, on average within 15 K, with the T EFF determinations of Bergeat et al. and a refinement of the carbon star angular size prediction based on V and K magnitudes is presented that is good to an rms of 12%. A subsample of our stars have sufficient {u, v} coverage to permit non-spherical modeling of their photospheres, and a general tendency for detection of statistically significant departures from sphericity with increasing interferometric signal-to-noise is seen. The implications of most - and potentially all - carbon stars being non-spherical is considered in the context of surface inhomogeneities and a rotation-mass-loss connection. |
Keywords | infrared: stars; high angular resolution; interferometers; carbon stars; star distances; star fundamental parameters |
Contains Sensitive Content | Does not contain sensitive content |
ANZSRC Field of Research 2020 | 510109. Stellar astronomy and planetary systems |
519999. Other physical sciences not elsewhere classified | |
Public Notes | For access to this article, please click on the URL link provided. |
Byline Affiliations | Lowell Observatory, United States |
University of Vienna, Austria | |
National Institute of Astrophysics, Italy | |
California Institute of Technology (Caltech), United States | |
Institution of Origin | University of Southern Queensland |
https://research.usq.edu.au/item/q4359/the-pti-carbon-star-angular-size-survey-effective-temperatures-and-non-sphericity
1169
total views115
total downloads1
views this month0
downloads this month