* Astronomy

Members Login
Username 
 
Password 
    Remember Me  
Home -> Astronomy News -> Exoplanets -> KIC 05807616
Post Info TOPIC: KIC 05807616
Blobrana


L

Posts: 131433
Date:
KIC 05807616
Permalink  
 

Title: A compact system of small planets around a former red-giant star
Authors: S. Charpinet, G. Fontaine, P. Brassard, E. M. Green, V. Van Grootel, S. K. Randall, R. Silvotti, A. S. Baran, R. H. Ostensen, S. D. Kawaler & J. H. Telting

Planets that orbit their parent star at less than about one astronomical unit (1 AU is the Earth-Sun distance) are expected to be engulfed when the star becomes a red giant. Previous observations have revealed the existence of post-red-giant host stars with giant planets orbiting as close as 0.116 AU or with brown dwarf companions in tight orbits, showing that these bodies can survive engulfment. What has remained unclear is whether planets can be dragged deeper into the red-giant envelope without being disrupted and whether the evolution of the parent star itself could be affected. Here we report the presence of two nearly Earth-sized bodies orbiting the post-red-giant, hot B subdwarf star KIC 05807616 at distances of 0.0060 and 0.0076 AU, with orbital periods of 5.7625 and 8.2293 hours, respectively. These bodies probably survived deep immersion in the former red-giant envelope. They may be the dense cores of evaporated giant planets that were transported closer to the star during the engulfment and triggered the mass loss necessary for the formation of the hot B subdwarf, which might also explain how some stars of this type did not form in binary systems.

Source



__________________
Blobrana


L

Posts: 131433
Date:
Permalink  
 

Title: A tidally destructed massive planet as the progenitor of the two light planets around the sdB star KIC 05807616
Authors: Ealeal Bear, Noam Soker (Technion, Israel)

We propose that the two newly detected Earth-size planets around the hot B subdwarf star KIC 05807616 are remnant of the tidally destructed metallic core of a massive planet. A single massive gas-giant planet was spiralling-in inside the envelope of the red giant branch star progenitor of the extreme horizontal branch (EHB) star KIC 05807616. The released gravitational energy unbound most of the stellar envelope, turning it into an EHB star. The massive planet reached the tidal destruction radius of ~Ro from the core, where the planet's gaseous envelope was tidally removed. In our scenario the metallic core of the massive planet was tidally destructed into several Earth-like bodies immediately after the gaseous envelope of the planet was removed. Two, and possibly more, Earth-size fragments survived at orbital separations of >Ro within the gaseous disk. The bodies interact with the disk and among themselves and migrated to reach orbits close to a 3:2 resonance. These observed planets can have a planetary magnetic field about ten times as strong as that of Earth. This strong magnetic field can substantially reduce the evaporation rate from the planets and explain their survivability against the strong UV radiation of the EHB star.

Read more (8kb, PDF)



__________________
Blobrana


L

Posts: 131433
Date:
KOI 55.01 and KOI 55.02
Permalink  
 

Astronomers Discover Deep-Fried Planets

Two Earth-sized planets have been discovered around a dying star that has passed the red giant stage. This discovery, published in the science journal Nature, may shed new light on the destiny of stellar and planetary systems, including our solar system.
Two Earth-sized planets have been discovered circling a dying star that has passed the red giant stage. Because of their close orbits, the planets must have been engulfed by their star while it swelled up to many times its original size.
This discovery, published in the science journal Nature, may shed new light on the destiny of stellar and planetary systems, including our solar system.
Read more 



__________________
Blobrana


L

Posts: 131433
Date:
KIC 05807616
Permalink  
 

Newly found planets are 'roasted remains'

Just a day after announcing the discovery of the first Earth-size planets ever detected outside our Solar System, scientists have confirmed the existence of two even smaller worlds.
There is something very unusual about these objects, however.
It appears they are the roasted remains of planets that spent a period of time inside the outer layers of their star.
Scientists tell Nature magazine that these worlds are therefore likely to have been much bigger in the past.
Read more 



__________________
Page 1 of 1  sorted by
 
Quick Reply

Please log in to post quick replies.
Home -> Astronomy News -> Exoplanets -> KIC 05807616


Create your own FREE Forum
Report Abuse 		Powered by ActiveBoard