51 Pegasi b

51 Pegasi b ( also unofficially: Bellerophon ) is an exoplanet, orbiting the Sun-like star 51 Pegasi. He was discovered in 1995 as the first planet outside our solar system, orbiting a sun-like star. He also was the first celestial body that got the type of the " hot Jupiter".

Discovery

On 5 October 1995, the Swiss Professor Michel Mayor and Didier Queloz gave his staff from the Department of Astronomy at the University of Geneva, known in the " 9th Cambridge Workshop on Cool Stars, Stellar Systems and the Sun" in Florence, the first exoplanet around a our Sun to have been established.

The planet was observed using a high-resolution spectrograph, the lightweight, regular change of the radial velocity of the star of 70 m / s revealed. These variations possibly generated by the influence of a close, heavy sky body indicated from the outset on a jupiter large object in just 7 million kilometers away to 51 Pegasi out.

Seven days later, on October 12, 1995, Dr. Geoffrey Marcy of San Francisco State University and Dr. Paul Butler of the University of California, Berkeley confirm using the Hamilton spectrograph at Lick Observatory near San Jose, California, the existence of first unusual sounding satellites.

The discovery of this first exoplanet is considered a milestone in astronomical research.

Properties

51 Pegasi b is 0.46 Jupiter masses and rotates in 4.2 days at a distance of 0.05 astronomical units (AU ) once around the star. This corresponds to the twentieth of the distance between the Earth and our Sun ( AE = 1 ), or about one-eighth of the distance between the Sun and Mercury ( = 0.39 AU). The surface temperature of the planet was thus calculated to 1255 K ( 982 ° C).

Speculations about 51 Pegasi b

Although 51 Pegasi b, the first known extrasolar planet, no detailed data concerning him are available. There are numerous speculations on the planet, but not occupied by facts theses. The most common opinion so far is that it is a Jupiter-like gas giant, which is exposed by its proximity to the central star of extremely high radiation and tidal forces.

Recently found by the American astronomer David Latham and Robert Stefanik evidence for a second planet that is orbiting 51 Pegasi in a radius larger than 51 Pegasi b. However, the precise orbit and the exact mass of the body could not yet be determined.

• Exoplanet