astro.wikisort.org - Meteorite

TrES-4b is an extrasolar planet, and one of the largest exoplanets ever found, after WASP-12b, WASP-17b, CT Chamaeleontis b (though the latter may be a brown dwarf), GQ Lupi b and HD 100546 b. It was discovered in 2006, and announced in 2007, by the Trans-Atlantic Exoplanet Survey, using the transit method. It is approximately 1,400 light-years (430 pc) away orbiting the star GSC 02620-00648, in the constellation Hercules.[1]

TrES-4b

Size comparison of TrES-4 with Jupiter
Discovery
Discovered by	Mandushev et al.[1]
Discovery date	2006-2007
Detection method	Transit
Orbital characteristics
Semi-major axis	0.05091 ± 0.00071 AU (7,616,000 ± 106,000 km)[2]
Eccentricity	0
Orbital period (sidereal)	3.553945 ± 0.000075 d
Inclination	82.86 ± 0.33[2]
Semi-amplitude	86.1
Star	GSC 02620-00648 A[2]
Physical characteristics
Mean radius	1.799 ± 0.063[2] RJ
Mass	0.919 ± 0.073[2] MJ
Surface gravity	7.04 ± 1.12 m/s2 (23.1 ± 3.7 ft/s2) 0.718 ± 0.114 g
Temperature	1782 ± 29[2]

Orbit

A 2008 study concluded that the GSC 06200-00648 system (among others) is a binary star system allowing even more accurate determination of stellar and planetary parameters.[2]

TrES-4 orbits its primary star every 3.543 days and eclipses it when viewed from Earth.

The study in 2012, utilizing a Rossiter–McLaughlin effect, have determined the planetary orbit is probably aligned with the equatorial plane of the star, misalignment equal to 6.3±4.7°.[3]

Physical characteristics

The planet is slightly less massive than Jupiter (0.919 ± 0.073 M_J) but its diameter is 79.9% larger; it was considered the largest planet ever found at the time, giving it an average density of only about 1/3 gram per cubic centimetre, approximately the same as Saturn's moon Methone. This made TrES-4 both the largest known planet and the planet with the lowest known density at the time of its discovery.[2][1]

TrES-4's orbital radius is 0.05091 AU, giving it a predicted surface temperature of about 1782 K. This by itself is not enough to explain the planet's low density, however. It is not currently known why TrES-4 is so large. The probable causes are the proximity to a parent star that is 3–4 times more luminous than the Sun as well as the internal heat within the planet.[2][1]

See also

• List of exoplanet extremes
• WASP-17b, another large exoplanet

References

External links

Media related to TrES-4 at Wikimedia Commons

• "Team finds largest exoplanet yet". BBC News. 7 August 2007.
• "New monster planet 'could float on water'". ABC News (Australia). 7 August 2007.
• Than, Ker (August 6, 2007). "Largest Known Exoplanet Discovered". Space.com news service. Retrieved 2007-08-07.
• Muir, Hazel (August 6, 2007). "Largest known exoplanet puzzles astronomers". NewScientist.com news service. Retrieved 2007-08-07.

На других языках

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[de] TrES-4

TrES-4, auch TrES-4 b genannt, ist ein Exoplanet im Sternbild Herkules und etwa 440 Parsec (ca. 1.400 Lj) von der Erde entfernt. Er besteht hauptsächlich aus Wasserstoff und hat eine äußerst geringe Dichte. TrES-4 kreist um den Stern GSC 02620-00648 mit einer Umlaufzeit von 3,55 Tagen.

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- [en] TrES-4b

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[es] TrES-4b

TrES-4 es un exoplaneta descubierto en 2007 por la Trans-Atlantic Exoplanet Survey utilizando el método tránsito. Se encuentra a 1.400 años luz de la constelación de Hércules.[3]

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[ru] TrES-4 A b

TrES-4 A b — экзопланета (газовый гигант, горячий юпитер, рыхлая планета). Является единственной известной на сегодняшний день планетой в двойной системе[2] TrES 4 AB, которая удалена от Земли на 1600 световых лет в направлении созвездия Геркулеса[3]. TrES-4 A b была открыта в рамках программы «Trans-Atlantic Exoplanet» (TrES) транзитным методом в 2006 году, однако об открытии было объявлено лишь год спустя в 2007 году[2].

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