51 Eridani b

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Exoplanet
51 Eridani b
Constellation Eridanus
Position
equinox : J2000.0
Right ascension 04h 37m 36.13234s
declination −02 ° 28 ′ 24.7749 ″
Orbit data
Central star 51 Eridani
Major semi-axis 14.0  +7.0−3.0 AE
eccentricity 0.21 ± 0.15
Period of circulation 14965.0  +12775.0−4380.0 d
Further data
radius 1.11   +0.13−0.16R J
Dimensions 9.1   +4.9−3.3 M J
distance 29.4 ± 0.3 pc
history
discovery B. Macintosh et al.
Date of discovery 2015

51 Eridani b is a Exoplanet that the approximately 96 light years from the sun remote main sequence star 51 Eridani in the constellation Eridanus orbits.

discovery

51 Eridani b was discovered by a team of astronomers led by Bruce Macintosh from Stanford University using the Gemini Planet Imager instrument at the Gemini South observatory in Chile through direct imaging in the near infrared and the discovery was announced on August 13, 2015. The central star was observed from December 2014 as the 44th target as part of an observation campaign comprising 600 nearby and young stars. A background star could be excluded as an explanation through subsequent investigations and archive data. At the time of discovery, 51 Eridani b was the exoplanet with the lowest mass that could be directly imaged.

properties

The central star - and thus the planet - is very young and only 20 million years old. Due to the direct imaging, there is the possibility of spectral investigation and measurement of its atmospheric composition. The infrared spectrum of 51 Eridani b shows clear absorption bands of methane and hydrogen . According to model calculations, the effective temperature of the planet is between 600 and 750 Kelvin , while the mass is between 2 and 12 Jupiter's masses .

The distance of 51 Eridani b to its central star corresponds, according to the first observations, to about thirteen times the distance of the earth to the sun, whereby the distance of the planet from 51 Eridani, transferred to the solar system , roughly between that of Saturn and Uranus from the sun would lie. Due to the relatively short period between the first observations and the announcement of the discovery, the orbital motion of the planet around 51 Eridani could not yet be proven.

The observation data suggest a formation of the planet similar to that of Jupiter , according to which a so-called planetary embryo has attracted matter and gas.

The existence of the planet could be confirmed by further observations with the Gemini Planet Imager, whereas previously it had not been completely ruled out that the object is a T-dwarf that just happens to be in the same direction. Astrometric measurements suggest a large orbital half-axis of around 14 AU and an orbital period of approximately 41 years.

Individual evidence

  1. ↑ SIMBAD: 51 Eri. Retrieved August 14, 2015 .
  2. ↑ a b c d Extrasolar Planets Encyclopaedia: Planet 51 Eri b. Retrieved August 14, 2015 .
  3. ^ A b Gemini Observatory: Gemini-Discovered World is Most like Jupiter. Retrieved August 14, 2015 .
  4. ↑ a b c d e f B. Macintosh et al .: Discovery and spectroscopy of the young Jovian planet 51 Eri b with the Gemini Planet Imager . arxiv : 1508.03084 .
  5. ↑ a b c d e Stars and Space from August 13, 2015: A young Jupiter orbiting 51 Eridani discovered. Retrieved August 14, 2015 .
  6. ^ A b De Rosa et al .: Astrometric Confirmation and Preliminary Orbital Parameters of the Young Exoplanet 51 Eridani b with the Gemini Planet Imager . arxiv : 1509.07514 .