Tyche (planet)

from Wikipedia, the free encyclopedia

Tyche is a hypothetical planet ( gas giant , Planet X ) in the solar system in the Oort cloud at a distance to the sun in the range 10,000–40,000 AU .

theory

Such a planet was first mentioned in 1999 by the astronomer John B. Murray (from the Open University in Great Britain) as a possibility to explain the orbital peculiarities of a special group of long-period comets . He named a distance to the sun of approx. 32,000 AU (4.8 × 10 12 km; almost half a light year ) and an orbital period of 5.8 million years. The mass must be "large in relation to the known planets". The probability that the correlation of the orbital data of the 13 comets examined is random is 0.0006.

Independently of this, such a planet was postulated around the same time by a group around John Matese (from the University of Louisiana at Lafayette ), also as an explanation for statistical abnormalities in the orbital data of a group of comets. A distance of about 25,000 AU and a mass of about 1.5 Jupiter's masses are mentioned here.

The theory is not shared by many astronomers.

Differentiation from other hypotheses

The Tyche hypothesis differs from other hypotheses on previously undiscovered celestial bodies in the solar system, such as the planet-nine hypothesis (based on other statistical peculiarities of the solar system, both in the theoretical basis (especially in the facts to be explained) and in the resulting orbit data Orbital data of another celestial body group) or the nemesis hypothesis (based on a possible periodicity of mass extinctions ).

Verification possibility

Proof of the actual existence could have been provided by evaluating the data collected by the Wide-field Infrared Survey Explorer (WISE space telescope), but this has not happened (as of March 2016).

According to the latest findings (as of March 2014), the orbit would have to be at least 26,000 AU from the sun, because no other planet the size of Jupiter could be detected within this distance.

Origin of name

Tyche ( translated from Greek , it means "luck") was the Greek goddess of fate, lucky (or bad) chance and chance. The name was chosen to avoid confusion with an earlier hypothesis that the sun has a companion called Nemesis . Tyche was the name of the "good sister" of the goddess Nemesis . Such an object in the Oort Cloud was first named by Davy Kirpatrick from the California Institute of Technology .

Dimensions

According to speculations, Tyche has up to four times the mass of Jupiter and a relatively high temperature of around 200 K (approx. −70 ° C).

See also

Web links

Individual evidence

  1. ^ John B. Murray: Arguments for the Presence of a Distant Large Undiscovered Solar System Planet . In: Monthly Notices of the Royal Astronomical Society . 309, No. 1, October 11, 1999, pp. 31-34. bibcode : 1999MNRAS.309 ... 31M . doi : 10.1046 / j.1365-8711.1999.02806.x . - Quote from the abstract : “Aphelion distances of long-period comets show a slight excess around 30,000 to 50,000 au… This paper examines one of the possible explanations for this non-random clustering.”
  2. ↑ John J. Matese, Patrick G. Whitman, Daniel P. Whitmire: Cometary Evidence of a Massive Body in the Outer Oort Clouds . In: Icarus . 141, No. 2, 1999, p. 354. bibcode : 1999Icar..141..354M . doi : 10.1006 / icar.1999.6177 . - Quote from the abstract : “Approximately 25% of the 82 new class I Oort cloud comets have an anomalous distribution of orbital elements that can best be understood if there exists a bound perturber in the outer Oort cloud.”
  3. ↑ Natalie Wolchover: Astronomers Doubt Giant Planet 'Tyche' Exists in Our Solar System. space.com, February 15, 2011, accessed April 4, 2016 .
  4. ↑ Ralph-Mirko Richter: WISE: No Planet X in the Outer Solar System in raumfahrer.net, Date: March 11, 2014, Accessed: March 14, 2014