Difference between revisions of "Triggers:Flares"
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[[File:yzcmi_spec.png|thumb|450px|border|left|Example of a flare spectrum with an excess of radiation at short wavelengths and pronounced Balmer emission lines. From [http://adsabs.harvard.edu/abs/2010ApJ...714L..98K Kowalski 2010].]] | [[File:yzcmi_spec.png|thumb|450px|border|left|Example of a flare spectrum with an excess of radiation at short wavelengths and pronounced Balmer emission lines. From [http://adsabs.harvard.edu/abs/2010ApJ...714L..98K Kowalski 2010].]] | ||
− | [[File: | + | [[File:M_star_spectrum.png|thumb|450px|border|right|Spectrum of an M6 dwarf is extremely red. From [http://www.sdss3.org/dr8/data_access.php SDSS DR8]]] |
Revision as of 14:03, 11 September 2011
M dwarf flares
Statistical study of M dwarf flares in Stripe 82 is presented in Kowalski et al. 2009.
- Colour range for M-dwarfs (r − i) > 0.53 and (i − z) > 0.3 and (u-r) > 3
- The most flaring are late type M-dwarfs (M4-M6), earlier types (M2-M3) flare half as often as late types and M0-M1 dwarfs flare only 20% as often as late types.
- flares are the most pronounced in u-band
- around 35% of M-dwarfs are in binary systems - these have bluer u-g. Most single M-dwarfs will have u-g > 1.8
- g - K > 4 - significantly brighter in IR (2MASS cross-match) than Visual.
- amplitude in u > 0.7 mag up to 5 mag.
- large and small flares possible on the same star
- flaring fraction: 0.0108%, i.e. 1 of every 10,000 observation of a M-dwarf in Stripe 82 resulted in a flare
- Sloan (5yrs) flaring star probabilities for different types of Mdwarf: M0-M1: 38/35,000; M2-M3: 79/13,000; M4-M6: 119/2120.
- 1.3 flares per hour sq.deg with <math>\Delta u > 0.7</math> mag, with slightly more flares towards the galactic plane.
Light curve examples
![](/images/thumb/3/36/Uv_ceti.png/550px-Uv_ceti.png)
High temporal resolution observations of a flare from UV Cet star. From Bopp & Moffett 1973.
![](/images/thumb/c/cd/Yzcmi.png/450px-Yzcmi.png)
The YZ Cmi U-band flare. From Kowalski 2010
![](/images/thumb/7/7e/Cn_leo.png/350px-Cn_leo.png)
Outburst of the flare star CN Leo. From Sokolowski 2008.
![](/images/thumb/8/85/Gj3332.png/450px-Gj3332.png)
High temporal resolution observations of a flare star by Pi of the Sky. From Sokolowski 2008.
Spectrum examples
![](/images/thumb/d/d7/Yzcmi_spec.png/450px-Yzcmi_spec.png)
Example of a flare spectrum with an excess of radiation at short wavelengths and pronounced Balmer emission lines. From Kowalski 2010.
![](/images/thumb/e/e1/M_star_spectrum.png/450px-M_star_spectrum.png)
Spectrum of an M6 dwarf is extremely red. From SDSS DR8