What is Hot Jupiter?
'''Hot Jupiters''' are a class of [[gas giant]] [[exoplanet]]s that are physically similar to [[Jupiter]] but have very short [[orbital period]]s ({{nowrap|''P'' < 10 days}}).<ref>{{cite journal |doi=10.1088/0004-637X/799/2/229 |bibcode=2015ApJ...799..229W |volume=799 |issue=2 |journal=The Astrophysical Journal |page=229 |arxiv=1412.1731 |title=On the occurrence rate of hot Jupiters in different stellar environments |year=2015 |last1=Wang |first1=Ji |last2=Fischer |first2=Debra A. |last3=Horch |first3=Elliott P. |last4=Huang |first4=Xu|s2cid=119117019 }}</ref> They are close to their stars, with high surface-atmosphere temperatures.<ref>{{cite web |url=http://www.cbc.ca/news/technology/what-worlds-are-out-there-a-field-guide-to-exoplanets-1.3734359 |title=What worlds are out there? |work=[[Canadian Broadcasting Corporation]] |language=en |date=25 August 2016 |access-date=5 June 2017}}</ref> Hot Jupiters are usually [[tidally locked]]. Hot Jupiters are the easiest [[extrasolar planet]]s to detect by the [[radial velocity|radial-velocity]] method. The oscillations of their parent stars' motion are large and rapid compared to those of other types of planets. These oscillations are caused by the planet orbiting its star in the line of sight of the Earth. Since it seems that they are common, that raises the question of why the [[Solar System]] has its largest planet so far from its star. This led astronomers to think the Earth's Jupiter was first much closer to the Sun, and moved out later to its present orbit. One of the best-known hot Jupiters is {{nowrap|[[51 Pegasi b]]}}. Discovered in 1995, it was the first extrasolar planet found orbiting a Sun-like [[star]]. {{nowrap|51 Pegasi b}} has an [[orbital period]] of about 4&nbsp;days. == References == {{reflist}} [[Category:Exoplanets]] [[Category:Types of planet]]