Cannabaceae

TrES-4b
Size comparison of TrES-4 with Jupiter
Discovery
Discovered byMandushev et al[1]
Discovery date2006–2007
Transit
Orbital characteristics
0.05091 ± 0.00071 AU (7.616 ± 0.106 million km)[2]
Eccentricity0
3.553945 ± 0.000075 d
Inclination82.86 ± 0.33[2]
Semi-amplitude86.1
StarGSC 02620-00648 A[2]
Physical characteristics
1.799 ± 0.063[2] RJ
Mass0.919 ± 0.073[2] MJ
7.04 ± 1.12 m/s2 (23.1 ± 3.7 ft/s2)
0.718 ± 0.114 g
Temperature1782±29 K (1,509 °C; 2,748 °F, equilibrium)[2]

TrES-4b is an extrasolar planet, and one of the largest exoplanets ever found. 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]

Orbit

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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

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The planet is slightly less massive than Jupiter (0.919 ± 0.073 MJ) 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 a third of a gram per cubic centimetre, approximately the same as Saturn's moon Methone. This made TrES-4b both the largest-known planet and the planet with the lowest-known density at the time of its discovery.[2][1]

TrES-4b's orbital radius is 0.05091 AU, giving it a predicted surface temperature of about 1,782 K (1,509 °C; 2,748 °F). This by itself is not enough to explain the planet's low density, however. It is not currently known why TrES-4b is so large. The probable causes are the proximity to a parent star that is three to four times more luminous than the Sun as well as the internal heat within the planet.[2][1]

See also

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References

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  1. ^ a b c d Mandushev, Georgi; et al. (2007). "TrES-4: A Transiting Hot Jupiter of Very Low Density". The Astrophysical Journal Letters. 667 (2): L195–L198. arXiv:0708.0834. Bibcode:2007ApJ...667L.195M. doi:10.1086/522115. S2CID 6087170.
  2. ^ a b c d e f g h i Daemgen, S.; Hormuth, F.; Brandner, W.; Bergfors, C.; Janson, M.; Hippler, S.; Henning, T. (2009). "Binarity of transit host stars - Implications for planetary parameters" (PDF). Astronomy and Astrophysics. 498 (2): 567–574. arXiv:0902.2179. Bibcode:2009A&A...498..567D. doi:10.1051/0004-6361/200810988. S2CID 9893376.
  3. ^ Albrecht, Simon; Winn, Joshua N.; Johnson, John A.; Howard, Andrew W.; Marcy, Geoffrey W.; Butler, R. Paul; Arriagada, Pamela; Crane, Jeffrey D.; Shectman, Stephen A.; Thompson, Ian B.; Hirano, Teruyuki; Bakos, Gaspar; Hartman, Joel D. (2012), "Obliquities of Hot Jupiter Host Stars: Evidence for Tidal Interactions and Primordial Misalignments", The Astrophysical Journal, 757 (1): 18, arXiv:1206.6105, Bibcode:2012ApJ...757...18A, doi:10.1088/0004-637X/757/1/18, S2CID 17174530
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Media related to TrES-4 at Wikimedia Commons


One thought on “Cannabaceae

  1. Well, that’s interesting to know that Psilotum nudum are known as whisk ferns. Psilotum nudum is the commoner species of the two. While the P. flaccidum is a rare species and is found in the tropical islands. Both the species are usually epiphytic in habit and grow upon tree ferns. These species may also be terrestrial and grow in humus or in the crevices of the rocks.
    View the detailed Guide of Psilotum nudum: Detailed Study Of Psilotum Nudum (Whisk Fern), Classification, Anatomy, Reproduction

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