Difference between revisions of "Triggers:RCrB"
From Gaia Science Alerts Working Group
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[[File:figure_rcrb_mag.png|300px|right|thumb|Example of RCrB star in the LMC as seen by OGLE-II]] | [[File:figure_rcrb_mag.png|300px|right|thumb|Example of RCrB star in the LMC as seen by OGLE-II]] | ||
| − | Only around 50 known in the Galaxy and Magellanic Clouds. | + | Only around 50 known in the Galaxy and Magellanic Clouds. They are rare type of evolved carbon-rich supergiants that are thought to result from the merger of two white dwarfs, called the Double Degenerate (DD) scenario. This scenario is also studied in context of SN Ia explosions, therefore better understanding of RCrB stars is crucial. |
Characteristics: | Characteristics: | ||
* sudden and non-periodic drops in magnitude | * sudden and non-periodic drops in magnitude | ||
| − | * drops by up to | + | * drops by up to 9 magnitudes |
* some small variation in the baseline | * some small variation in the baseline | ||
* the "dark" stage can last from days to years | * the "dark" stage can last from days to years | ||
* recovers slowly to the baseline | * recovers slowly to the baseline | ||
| + | |||
| + | RCrB can be distinguished from other Red Giants based on the fact that an RCB’s circumstellar shell seem thinner than that of most common AGB stars [http://arxiv.org/abs/0905.3224 Tisserand et al. 2009]. | ||
| Line 16: | Line 18: | ||
[[File:DYPer.png|300px|right|thumb|Example OGLE light curve of DY Per-type candidate]] | [[File:DYPer.png|300px|right|thumb|Example OGLE light curve of DY Per-type candidate]] | ||
| − | + | These are another Carbon stars. Their drops in magnitude are much smaller than in RCrBs and seem to be periodical (P~1000d). | |
Revision as of 12:54, 12 October 2009
R Corona Borealis stars
Only around 50 known in the Galaxy and Magellanic Clouds. They are rare type of evolved carbon-rich supergiants that are thought to result from the merger of two white dwarfs, called the Double Degenerate (DD) scenario. This scenario is also studied in context of SN Ia explosions, therefore better understanding of RCrB stars is crucial.
Characteristics:
- sudden and non-periodic drops in magnitude
- drops by up to 9 magnitudes
- some small variation in the baseline
- the "dark" stage can last from days to years
- recovers slowly to the baseline
RCrB can be distinguished from other Red Giants based on the fact that an RCB’s circumstellar shell seem thinner than that of most common AGB stars Tisserand et al. 2009.
DY Persei
These are another Carbon stars. Their drops in magnitude are much smaller than in RCrBs and seem to be periodical (P~1000d).
