Astronomy and Astrophysics – Astrophysics – Solar and Stellar Astrophysics
Scientific paper
2010-04-08
Astronomy and Astrophysics
Astrophysics
Solar and Stellar Astrophysics
4 pages, 3 figures, accepted by A&A
Scientific paper
We present a Chandra observation of the exceptional planet bearing A5V star HR 8799, more precisely classified as a kA5hF0mA5 star and search for intrinsic X-ray emission. We clearly detect HR 8799 at soft X-ray energies with the ACIS-S detector in a 10 ks exposure; minor X-ray brightness variability is present during the observation. The coronal plasma is described well by a model with a temperature of around 3 MK and an X-ray luminosity of about Lx = 1.3 x 10^28 erg/s in the 0.2-2.0 keV band, corresponding to an activity level of log Lx/Lbol ~ -6.2. Altogether, these findings point to a rather weakly active and given a RASS detection, long-term stable X-ray emitting star. The X-ray emission from HR 8799 resembles those of a late A/early F-type stars, in agreement with its classification from hydrogen lines and effective temperature determination and thus resolving the apparent discrepancy with the standard picture of magnetic activity that predicts mid A-type stars to be virtually X-ray dark.
Robrade Jan
Schmitt Juergen H. M. M.
No associations
LandOfFree
X-ray emission from the remarkable A-type star HR 8799 does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with X-ray emission from the remarkable A-type star HR 8799, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and X-ray emission from the remarkable A-type star HR 8799 will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-713327