Abstract
The activity levels of stars are influenced by several stellar
properties, such as stellar rotation, spectral type, and the presence of
stellar companions. Analogous to binaries, planetary companions are also
thought to be able to cause higher activity levels in their host stars,
although at lower levels. Especially in X-rays, such influences are hard
to detect because coronae of cool stars exhibit a considerable amount of
intrinsic variability. Recently, a correlation between the mass of
close-in exoplanets and their host star's X-ray luminosity has been
detected, based on archival X-ray data from the ROSAT All-Sky Survey.
This finding has been interpreted as evidence for star-planet
interactions. We show in our analysis that this correlation is caused by
selection effects due to the flux limit of the X-ray data used and due
to the intrinsic planet detectability of the radial velocity method, and
thus does not trace possible planet-induced effects. We also show that
the correlation is not present in a corresponding complete sample
derived from combined XMM-Newton and ROSAT data.
| Original language | English |
|---|---|
| Pages (from-to) | 59 |
| Journal | The Astrophysical Journal |
| Volume | 735 |
| Issue number | 1 59 |
| Publication status | Published - 01 Jul 2011 |
Keywords
- planet-star interactions
- stars: activity
- stars: coronae
- X-rays: stars