Hot Jupiter "cast a shadow" on his star


02/02/2013

Darkening in the light of star HAT-P-7, caused a powerful gravity of Jupiter were recorded by scientists. Preprint of which will be published in the Journal of The Astrophysical Journal Letters, laid out in the archives of Cornell University, and a summary of its results ScienceNow.

Observations of the star HAT-P-7 astrophysics performed using an orbital telescope "Kepler", which measures changes in the light of the stars for the detection of eclipses, which may indicate the presence of extrasolar planets in the star system.

The system HAT-P-7 has been previously opened large gas giant - a planet related to the class of hot Jupiters. Massive planets of this class are a kind of intermediary that resides between the major planets and dwarf stars.

New research has allowed scientists to detect periodic brightness drop HAT-P-7, arising, according to scientists who are not thinking of having a new planet, and as a result of the so-called gravity darkening of the star. This phenomenon is explained by pulling the outer shell of the star gravity of the gas giant, thereby locally increasing its radius. For lifting of the star is characterized by slightly lower temperature and pressure, and hence the lower the brightness. This interaction is similar in its mechanics with the tides and do not have time for the movement of the gas giant.

Local temperature gravitational stains, according to calculations, was just below 0.18 degrees, however, "Kepler" sensitivity enough to fix it in the starlight HAT-P-7.

His work orbiting Kepler telescope launched in 2009. During this period, he was able to open more than 2 million candidates for extrasolar planets, of which were podtverzhdeny105. According to the statistical analysis of the data the telescope, planets, like Earth, as well as some of its weight in excess of the super-Earths are more common than gas giants in the universe.


Microwave water from moondust
Two German satellite will create the most detailed 3-D map of the entire surface of the Earth
Saturday will fly past Earth asteroid the size of a skyscraper
Scientists: Mars suitable for life
Secret of the origin of cosmic rays is getting trickier