What is TRAPPIST-1e?
'''TRAPPIST-1e''', also known as '''2MASS J23062928-0502285 e''', is a [[Terrestrial planet|rocky]], almost earth-size [[exoplanet]] orbiting within the [[habitable zone]] around the [[ultracool dwarf]] star [[TRAPPIST-1]] about {{convert|40|ly|pc|lk=on|abbr=off|sp=us}} away from Earth in the constellation of [[Aquarius (constellation)|Aquarius]]. Astronomers found the exoplanet by using the [[transit method]], in which the dimming effect that a planet causes as it crosses in front of its star is measured. {{Infobox planet|name=TRAPPIST-1e|image=TRAPPIST-1e artist impression 2018.png|caption=Artist's impression of TRAPPIST-1e from 2018, showed here as a [[tidally locked]] planet with a liquid ocean. The actual appearance of the exoplanet is right now unknown, but based on its density, it is likely not completely covered in water. <!-- DISCOVERY -->|discoverer=Spitzer Space Telescope|discovered=22 February 2017|discovery_method=Transit <!-- DESIGNATIONS --> <!-- ORBITAL -->|apsis=astron|aphelion={{val|0.0294322|0.000017|fmt=none}} [[astronomical unit|AU]]|perihelion={{val|0.0291335|0.000017|fmt=none}} [[astronomical unit|AU]]|semimajor=0.02928285 ± 3.4e-07<ref name=Grimm-Demory-etal-2018/> [[astronomical unit|AU]]|eccentricity={{val|0.00510|0.00058|fmt=none}}<ref name=Grimm-Demory-etal-2018/>|period=6.099043 ± 0.000015<ref name=Delrez-2018/> [[day|d]]|inclination={{val|89.860|0.10|0.12}}<ref name=Grimm-Demory-etal-2018/>|star=[[TRAPPIST-1]]<ref name=vanGrootel-Fernandes-etal-2017> {{cite journal |first1=Valerie |last1=van&nbsp;Grootel |first2=Catarina S. |last2=Fernandes |first3=Michaël |last3=Gillon |first4=Emmanuel |last4=Jehin |first5=Richard |last5=Scuflaire |first6=Adam J. |last6=Burgasser |first7=Artem |last7=Burdanov |first8=Laetitia |last8=Delrez |first9=Brice-Olivier |last9=Demory |first10=Julien |last10=de&nbsp;Wit |first11=Didier |last11=Queloz |first12=Amaury H.M.J. |last12=Triaud |display-authors=2