TOI-700 e
{{short description|Earth-size exoplanet in Dorado}}
{{Infobox planet
|name = TOI-700 e
|image = TOI700e_art.jpg
|caption = Artist's view of TOI-700 e. The large blue dot on the top left is TOI-700 d.
|discoverer = Emily Gilbert et al.; TESS
|discovered = January 2023
|discovery_method = Transit
|semimajor = {{val|0.1340|0.0022|ul=AU}}
|eccentricity = {{val|0.059|0.057|0.042}}
|period = {{val|27.80978|0.00046|0.00040|ul=d}}
|inclination = {{val|89.60|0.21|0.16|u=deg}}
|star = TOI-700
|mean_radius = {{val|0.953|0.089|0.075|ul=Earth radius}}
|mass =
|density =
|single_temperature =
}}
TOI-700 e is the second outermost known exoplanet orbiting TOI-700, a red dwarf star in the constellation of Dorado.
Host star
{{Main|TOI-700}}
TOI-700 is a red dwarf of spectral class M that is about 40% the mass and radius, and very roughly 50% of the temperature of the Sun.{{cite news |last=Wall |first=Mike |title=NASA's TESS Planet Hunter Finds Its 1st Earth-Size World in 'Habitable Zone' |url=https://www.space.com/nasa-tess-first-earth-size-habitable-exoplanet-toi-700d.html |date=6 January 2020 |work=Space.com |access-date=6 January 2020 |archive-date=3 May 2020 |archive-url=https://web.archive.org/web/20200503185631/https://www.space.com/nasa-tess-first-earth-size-habitable-exoplanet-toi-700d.html |url-status=live }} The star is bright with low levels of stellar activity. Over the 11 sectors observed with TESS, the star does not show a single white-light flare. The low rotation rate is also an indicator of low stellar activity.{{Cite journal|last1=Gilbert|first1=Emily A.|last2=Barclay|first2=Thomas|last3=Schlieder|first3=Joshua E.|last4=Quintana|first4=Elisa V.|last5=Hord|first5=Benjamin J.|last6=Kostov|first6=Veselin B.|last7=Lopez|first7=Eric D.|last8=Rowe|first8=Jason F.|last9=Hoffman|first9=Kelsey|last10=Walkowicz|first10=Lucianne M.|last11=Silverstein|first11=Michele L.|date=2020-01-03|title=The First Habitable Zone Earth-sized Planet from TESS. I: Validation of the TOI-700 System|journal=The Astronomical Journal|volume=160|issue=3|page=116|doi=10.3847/1538-3881/aba4b2|arxiv=2001.00952|bibcode=2020AJ....160..116G|s2cid=209862554 |doi-access=free }}
Orbit
TOI-700 e orbits its host star with an orbital period of 27.8 days, comparable with the Moon's orbital period of 27.5 Earth days. It has an orbital radius of about {{Convert|0.134|AU|e6km e6mi|abbr=unit|lk=on}}, less than half of that of Mercury to the Sun in the Solar System. It receives about 127% of Earth's sunlight from its host star.
TOI-700 e is in a near 4:3 orbital resonance with TOI-700 d.
Discovery
{{Planetary radius
| align =
| base = Earth
| Exoplanet = TOI-700 e
| radius = 95
}}In November 2021, a fourth possible planet, Earth-sized and receiving approximately 30% more flux from TOI-700 than Earth does from the Sun, was found at the inner edge of the habitable zone of TOI-700.{{cite web |url=https://exofop.ipac.caltech.edu/tess/target.php?id=150428135 |title=ExoFOP TIC 150428135 |date= |website=exofop.ipac.caltech.edu |publisher= |access-date=26 November 2021 |archive-date=20 April 2020 |archive-url=https://web.archive.org/web/20200420081345/https://exofop.ipac.caltech.edu/tess/target.php?id=150428135 |url-status=live }} In January 2023 the existence of this planet, designated TOI-700 e, was confirmed.{{cite web |url=https://exoplanets.nasa.gov/news/1720/second-earth-sized-world-found-in-systems-habitable-zone/ |title=Second Earth-sized World Found in System's Habitable Zone |last= |first= |date=10 January 2023 |website=exoplanets.nasa.gov |publisher=NASA |access-date=10 January 2023 |archive-date=10 January 2023 |archive-url=https://web.archive.org/web/20230110185430/https://exoplanets.nasa.gov/news/1720/second-earth-sized-world-found-in-systems-habitable-zone/ |url-status=live }}
Discovered in 2023, TOI-700 e is terrestrial exoplanet that NASA claims to be an "earth-like" planet, with 95 percent of the Earth’s radius. Discovered by NASA's TESS (Transiting Exoplanet Survey Satellite), TOI-700 e has mass of about 0.818 Earths and takes 27.8 days to orbit once around its star.{{Cite web |last=Kazmierczak |first=Jeanette |date=2023-01-09 |title=NASA's TESS Discovers Planetary System's Second Earth-Size World |url=http://www.nasa.gov/feature/nasa-s-tess-discovers-planetary-system-s-second-earth-size-world |access-date=2023-03-20 |website=NASA |archive-date=2023-03-15 |archive-url=https://web.archive.org/web/20230315210530/https://www.nasa.gov/feature/nasa-s-tess-discovers-planetary-system-s-second-earth-size-world/ |url-status=live }} The planet is in a habitable zone distance from the M-type star TOI-700 it orbits, leading NASA scientists to believe that there is potential for liquid water on its surface. Ten percent smaller than its neighboring planet TOI-700 d, both are at a distance from their sun to be considered habitable, however, TESS requires an additional year to acquire more data about the exoplanets.{{Cite web |last=Kazmierczak |first=Jeanette |date=2023-01-09 |title=NASA's TESS Discovers Planetary System's Second Earth-Size World |url=http://www.nasa.gov/feature/nasa-s-tess-discovers-planetary-system-s-second-earth-size-world |access-date=2023-04-16 |website=NASA |archive-date=2023-03-31 |archive-url=https://web.archive.org/web/20230331004107/https://www.nasa.gov/feature/nasa-s-tess-discovers-planetary-system-s-second-earth-size-world/ |url-status=live }} Being one in only about a dozen habitable zone planets known, further research and data collection of the TOI-700 solar system are important for understanding Earth-like planets.{{Citation |last=Haghighipour |first=Nader |title=Kepler 186f: First Earth-Sized Planet in Habitable Zone |date=2015 |url=http://link.springer.com/10.1007/978-3-662-44185-5_5294 |encyclopedia=Encyclopedia of Astrobiology |pages=1325–1326 |editor-last=Gargaud |editor-first=Muriel |access-date=2023-04-16 |place=Berlin, Heidelberg |publisher=Springer Berlin Heidelberg |language=en |doi=10.1007/978-3-662-44185-5_5294 |bibcode=2015enas.book.1530H |isbn=978-3-662-44184-8 |editor2-last=Irvine |editor2-first=William M. |editor3-last=Amils |editor3-first=Ricardo |editor4-last=Cleaves |editor4-first=Henderson James |archive-date=2023-10-05 |archive-url=https://web.archive.org/web/20231005005501/https://link.springer.com/referenceworkentry/10.1007/978-3-662-44185-5_5294 |url-status=live }}
References
{{reflist|refs=
{{cite journal |last1=Gilbert |first1=Emily A. |last2=Vanderburg |first2=Andrew |display-authors=etal |date=January 2023 |title=A Second Earth-Sized Planet in the Habitable Zone of the M Dwarf, TOI-700 |journal=The Astrophysical Journal Letters |volume= 944|issue= 2|pages= L35|doi= 10.3847/2041-8213/acb599|arxiv=2301.03617|bibcode=2023ApJ...944L..35G |s2cid=255570018 |doi-access=free }}
}}
{{2023 in space}}
{{Stars of Dorado}}
Category:Exoplanets discovered in 2023
Category:Exoplanets discovered by TESS