Massachusetts Institute of Technology | 2017 Feb 14
Jennifer Chu wrote:
Scientists observe first planet-induced stellar pulsations.
[img3="For the first time, astronomers have observed a star pulsing in response to its orbiting planet. The star, HAT-P-2, pictured, is one of the most massive exoplanets known today. The planet, named HAT-P-2b, tracks its star in a highly eccentric orbit, flying extremely close to and around the star, then hurtling far out before eventually circling back around. Image courtesy of NASA (edited by MIT News)"]http://news.mit.edu/sites/mit.edu.newso ... ulse_0.jpg[/img3][hr][/hr]For the first time, astronomers from MIT and elsewhere have observed a star pulsing in response to its orbiting planet.
The star, which goes by the name HAT-P-2, is about 400 light years from Earth and is circled by a gas giant measuring eight times the mass of Jupiter — one of the most massive exoplanets known today. The planet, named HAT-P-2b, tracks its star in a highly eccentric orbit, flying extremely close to and around the star, then hurtling far out before eventually circling back around.
The researchers analyzed more than 350 hours of observations of HAT-P-2 taken by NASA’s Spitzer Space Telescope, and found that the star’s brightness appears to oscillate ever so slightly every 87 minutes. In particular, the star seems to vibrate at exact harmonics, or multiples of the planet’s orbital frequency — the rate at which the planet circles its star.
The precisely timed pulsations have lead the researchers to believe that, contrary to most theoretical model-based predictions of exoplanetary behavior, HAT-P-2b may be massive enough to periodically distort its star, making the star’s molten surface flare, or pulse, in response. ...
Spitzer Hears Stellar 'Heartbeat' from Planetary Companion
NASA | JPL-Caltech | Spitzer | 2017 Feb 14
Planet-Induced Stellar Pulsations in HAT-P-2's Eccentric System - Julien de Wit et al
- Astrophysical Journal Letters 836(2):L17 (2017 Feb 20) DOI: 10.3847/2041-8213/836/2/L17
arXiv.org > astro-ph > arXiv:1702.03797 > 13 Feb 2017