Academic Journal
Self-Correlation Analysis of R Coronae Borealis Stars: A Pilot Project
| العنوان: | Self-Correlation Analysis of R Coronae Borealis Stars: A Pilot Project |
|---|---|
| المؤلفون: | John R. Percy, Kaushala Bandara, J. Donald Fernie, P. L. Cottrell, Ljiljana Skuljan |
| المساهمون: | The Pennsylvania State University CiteSeerX Archives |
| المصدر: | http://www.aavso.org/publications/ejaavso/v33n1/27.pdf. |
| سنة النشر: | 2005 |
| المجموعة: | CiteSeerX |
| الوصف: | R. Coronae Borealis (RCB) stars are peculiar yellow supergiant stars which suddenly and unpredictably decrease in brightness by up to several magnitudes, then slowly return to normal. Most (perhaps all) RCB stars also pulsate, and the pulsations may be related to the ejection of the dust clouds which produce the fadings. As a pilot project, we have applied self-correlation analysis to two datasets: long-term photometry of R CrB itself by J. D. Fernie, and long-term photometry of several southern RCB stars by P. L. Cottrell, L. Skuljan, and their colleagues. Self-correlation is a simple form of time series analysis which displays the cycle-to-cycle behavior of a variable star, averaged over a dataset. It is especially useful for semiregular variables. Generally, the seasonal pulsation time scales and amplitudes which we derive are in agreement with Fourier analysis of the same datasets. In the case of R CrB, we confirm that there is apparent mode-switching from season to season. 1. What are RCB stars? R Coronae Borealis (RCB) stars are low-mass, carbon-rich, hydrogen-poor, yellow supergiants in an advanced stage of evolution: they may be merged white dwarfs, or undergoing a final helium flash (a “burp ” in their nuclear fusion processes) in the course of changing from an asymptotic giant branch star to a white dwarf. They are also variable stars: most famously, they undergo sudden, unpredictable, irregular, rapid (weeks) fadings of up to 10 magnitudes, then slow (months) returns to normal. They also undergo small-amplitude semiregular variability, with periods of tens of days, due to radial pulsation. Only a few dozen are known; there may be hundreds more waiting to be discovered and studied in our |
| نوع الوثيقة: | text |
| وصف الملف: | application/pdf |
| اللغة: | English |
| Relation: | http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.98.7920; http://www.aavso.org/publications/ejaavso/v33n1/27.pdf |
| الاتاحة: | http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.98.7920 http://www.aavso.org/publications/ejaavso/v33n1/27.pdf |
| Rights: | Metadata may be used without restrictions as long as the oai identifier remains attached to it. |
| رقم الانضمام: | edsbas.F77475FA |
| قاعدة البيانات: | BASE |
| الوصف غير متاح. |