HD 192699 b

from Wikipedia, the free encyclopedia

HD 192699 b is an exoplanet orbiting the yellow subgiant HD 192699 . Due to its high mass , it is assumed that it is a gas planet .

discovery

The planet was discovered using the radial velocity method. The data come from observations at the Keck and Lick observatories . The discovery was published by John Asher Johnson and co-workers in August 2007 . At the same time, the discovery of the exoplanets HD 175541 b and HD 210702 b was announced.

Track properties

The planet orbits its star at a mean distance of approximately 1.16 astronomical units . With its relatively high eccentricity of 14.9%, the distance fluctuates between 1.15 and 1.33 astronomical units within a planetary year. One orbit takes 351.5 earth days . Despite the orbit, which is slightly wider than the Earth, this is less than an earth year, because HD 192699 b has a higher orbital speed (36.0 km / s compared to 29.8 km / s) due to the high mass of its central star.

Physical Properties

HD 192699 b has a minimum mass of approx. 794.8 Earth masses or 2.5 Jupiter masses. The true mass cannot be determined without knowledge of the orbit inclination towards the observer, so it remains unclear for the time being. In all probability, HD 192699 b has a Jupiter-like expansion and is correspondingly denser .

Like the well-known gas giants, it should consist mainly of light elements, i.e. above all hydrogen and helium . HD 192699 b is in an Earth-like orbit. However, it receives more warmth from its larger and more luminous star. It is estimated that the planet has an average temperature of around 100 ° C. Seasonal fluctuations, which then affect the entire planet, are to be assumed because of the eccentric orbit. HD 192699 b probably shows a predominantly cloudless surface that appears blue due to Rayleigh scattering . It is possible that, at least in the Apastron, it also forms white hydrogen clouds in the colder polar regions.

swell

Web links