View source for TrES-4b

{{Short description|Hot Jupiter exoplanet orbiting a Sun-like star}}
{{Infobox planet
| name = TrES-4b
| image = TrES-4.jpg
| caption = Size comparison of TrES-4 with Jupiter
<!-- DISCOVERY           -->| discoverer = Mandushev ''et al''<ref name="Mandushev2007"/>
| discovered = 2006–2007
| discovery_method = [[Transit method|Transit]]
<!-- DESIGNATIONS        -->
<!-- ORBITAL             -->| apsis = astron
| semimajor = {{convert|0.05091|±|0.00071|AU|e6km|abbr=unit}}<ref name="binary"/>
| eccentricity = 0
| period = 3.553945 ± 0.000075 [[day|d]]
| inclination = 82.86 ± 0.33<ref name="binary"/>
| semi-amplitude = 86.1
| star = [[GSC 02620-00648]] A<ref name="binary"/>
<!-- PHYS CHARS          -->| mean_radius = {{val|1.838|0.240|0.238|ul=Jupiter radius}}<ref name=Johns/>
| mass = {{val|0.78|0.19|ul=Jupiter mass}}<ref name=Johns>{{Cite journal |last1=Johns |first1=Daniel |last2=Marti |first2=Connor |last3=Huff |first3=Madison |last4=McCann |first4=Jacob |last5=Wittenmyer |first5=Robert A. |last6=Horner |first6=Jonathan |last7=Wright |first7=Duncan J. |date=2018-11-01 |title=Revised Exoplanet Radii and Habitability Using Gaia Data Release 2 |bibcode=2018ApJS..239...14J |journal=The Astrophysical Journal Supplement Series |volume=239 |issue=1 |pages=14 |doi=10.3847/1538-4365/aae5fb |doi-access=free |arxiv=1808.04533 |issn=0067-0049}}</ref>
| surface_grav = {{cvt|7.04|±|1.12|m/s2|lk=on}}<br>0.718 ± 0.114 [[g-force|g]]
| density = {{val|0.156|0.072|0.071|ul=g/cm3}}<ref name=Johns/>
| single_temperature = {{val|1782|29|ul=K|fmt=commas}} ({{convert|1782|K|C F|disp=out}}, [[planetary equilibrium temperature|equilibrium]])<ref name="binary"/>
<!-- ATMOSPHERE          --> 
<!-- NOTES               -->}}
'''TrES-4b''' is an [[exoplanet]]. It was discovered in 2006, and announced in 2007, by the [[Trans-Atlantic Exoplanet Survey]], using the [[Methods of detecting extrasolar planets#Transit photometry|transit method]]. At the time of its discovery TrES-4 was the [[List of largest exoplanets#Chronological list of largest exoplanets|largest confirmed exoplanet ever found]], now more than 10 [[List of largest exoplanets|larger planets have been discovered]]. It is approximately {{convert|1400|ly|pc|lk=on}} away orbiting the star [[GSC 02620-00648]], in the constellation [[Hercules (constellation)|Hercules]].<ref name="Mandushev2007">{{cite journal |last=Mandushev |first=Georgi |display-authors=etal |date=2007 |title=TrES-4: A Transiting Hot Jupiter of Very Low Density |journal=The Astrophysical Journal Letters |volume=667 |issue=2 |pages=L195–L198 |doi=10.1086/522115 |bibcode=2007ApJ...667L.195M|arxiv = 0708.0834 |s2cid=6087170 }}</ref>

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

A 2008 study concluded that the GSC 02620-00648 system (among others) is a [[binary star]] system allowing even more accurate determination of stellar and planetary parameters.<ref name="binary">{{cite journal| url=http://www.mpia.de/homes/henning/Publications/daemgen.pdf| title=Binarity of transit host stars - Implications for planetary parameters| date=2009| volume=498
| pages=567–574| last1=Daemgen| first1=S.| journal=[[Astronomy and Astrophysics]]| doi=10.1051/0004-6361/200810988| last2=Hormuth
| first2=F.| last3=Brandner| first3=W.| last4=Bergfors| first4=C.| last5=Janson| first5=M.| last6=Hippler| first6=S.| last7=Henning| first7=T.| issue=2| bibcode=2009A&A...498..567D|arxiv = 0902.2179 | s2cid=9893376}}</ref>

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 {{val|6.3|4.7}}°.<ref>{{cite journal|arxiv=1206.6105|title=Obliquities of Hot Jupiter Host Stars: Evidence for Tidal Interactions and Primordial Misalignments|year=2012|doi=10.1088/0004-637X/757/1/18|last1=Albrecht|first1=Simon|last2=Winn|first2=Joshua N.|last3=Johnson|first3=John A.|last4=Howard|first4=Andrew W.|last5=Marcy|first5=Geoffrey W.|last6=Butler|first6=R. Paul|last7=Arriagada|first7=Pamela|last8=Crane|first8=Jeffrey D.|last9=Shectman|first9=Stephen A.|last10=Thompson|first10=Ian B.|last11=Hirano|first11=Teruyuki|last12=Bakos|first12=Gaspar|last13=Hartman|first13=Joel D.|journal=The Astrophysical Journal|volume=757|issue=1 |page=18|bibcode=2012ApJ...757...18A |s2cid=17174530}}</ref>

==Physical characteristics==
The planet is slightly less massive than [[Jupiter]] (0.919 ± 0.073 {{Jupiter mass|link=y}}) but its diameter is 84% larger. This give TrES-4 an average density of only about a third of a gram per cubic centimetre, approximately the same as [[Saturn]]'s moon [[Methone (moon)|Methone]]. At the time of its discovery in 2007, TrES-4 was both the largest-known planet and the planet with the lowest-known density.<ref name="binary"/><ref name="Mandushev2007"/>

TrES-4b's orbital radius is 0.05091 [[Astronomical unit|AU]], giving it a predicted surface temperature of about {{cvt|1782|K|C F|lk=on}}. 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.<ref name="binary"/><ref name="Mandushev2007"/>

==See also==
* [[List of exoplanet extremes]]
* [[WASP-17b]], another large exoplanet

==References==
{{Reflist}}

==External links==
{{commonscat-inline|TrES-4 b|TrES-4}}
* {{cite news |url=http://news.bbc.co.uk/1/hi/sci/tech/6934603.stm |access-date=14 May 2023 |title=Team finds largest exoplanet yet |publisher=[[BBC News]] |date=7 August 2007}}
* {{cite news |url=https://www.abc.net.au/news/2007-08-08/new-monster-planet-could-float-on-water/2525292 |access-date=14 May 2023 |title=New monster planet 'could float on water' |publisher=[[ABC News (Australia)]] |last1=Miller |first1=Barbara |last2=staff reporters |date=7 August 2007}}
* {{cite news |url=https://www.space.com/4151-largest-exoplanet-discovered.html |title=Largest Known Exoplanet Discovered |date=6 August 2007 |publisher=[[Space.com]] news service |first=Ker |last=Than |access-date=14 May 2023}}
* {{cite news |url=https://www.newscientist.com/article/dn12430-largest-known-exoplanet-puzzles-astronomers/ |title=Largest known exoplanet puzzles astronomers |date=6 August 2007 |publisher=[[NewScientist.com]] news service |first=Hazel |last=Muir |access-date=14 May 2023}}

{{Sky|17|53|13|+|37|12|42|1400}}

{{DEFAULTSORT:Tres-4b}}
[[Category:Hercules (constellation)]]
[[Category:Hot Jupiters]]
[[Category:Transiting exoplanets]]
[[Category:Exoplanets discovered in 2006]]
[[Category:Giant planets]]