Flare Stars
Just like our Sun has explosions on its surface ,
which we call flares, flare stars have momentary brightenings
observed on them. Generally their characteristics are:
-
Nearby
-
Stars with spots
-
Spectral Class type M (ie ~3000K)
-
Intrinsically faint
-
Rotating rapidly
-
Emission Lines (ie H-Alpha, Ca II H&K)
-
X-ray sources
The flares:
-
Rise to peak brightness very rapidly
-
Decay to normal brightness in an exponential curve
-
Blue amplitude is much larger than Red
-
Lots of X-ray emission
-
Occur at unpredicable times
-
Larger amplitudes(0.5 R mag) last for longer times
(hours)
We have discovered a few of these stars, since we started
looking at X-ray sources.
| BL Psc |
B.Kellett, G.Bromage, et.al |
ApJ.438,p354 |
1995 |
RE0044+09 |
| QT And |
RM Robb |
IBVS 4652 |
1995 |
RE0041+342 |
| ?? Peg |
R. Greimel and RM Robb |
IBVS 4652 |
1998 |
RX220111+2818 |
| ?? CVn |
RM Robb, DD Balam, R Greimel |
IBVS 4714 |
1999 |
RX133146+291631 |
Light curve of the latest star
This is a plot of our observations of the brightness variations of the
star RX1620. The dots and pluses are from
last year and the circles and x's are from this year. Some of us think the
variations are caused by spots, but the cause could still be
pulsations of the star.
for more info mail me at
robb@
uvic.ca
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