Astronomy:TOI 700 d

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Short description: Goldilocks terrestrial planet orbiting TOI 700
TOI 700 d
PIA23407-TOI700-PlanetarySystem.jpg
Simulation of the planetary system of TOI 700 (center) and its habitable zone, with planet d orbiting inside it.
Discovery
Discovered byEmily Gilbert
Discovery date3 January 2020
Transit
Orbital characteristics
0.163±0.015 AU
Eccentricity0.110+0.140
−0.079
[1]
Orbital period37.4260+0.0007
−0.0010
d
Inclination89.73+0.15
−0.12
deg
StarTOI 700
Physical characteristics
Mean radius1.19 ± 0.11 R[2]
Mass1.72+1.29
−0.63
M[2]
PhysicsTeq: 268.8 K (−4.3 °C; 24.2 °F)[1]


TOI 700 d is a near-Earth-sized exoplanet, likely rocky, orbiting within the habitable zone of the red dwarf TOI 700, the outermost planet within the system. It is located roughly 101.4 light-years (31.1 pc) away from Earth in the constellation of Dorado. The exoplanet is the first Earth-sized exoplanet in the habitable zone discovered by the Transiting Exoplanet Survey Satellite (TESS).[3][4][5]

TOI 700 d orbits its star at a distance of 0.163 AU (24,400,000 km; 15,200,000 mi) from its host star with an orbital period of roughly 37.4 days, has a mass 1.69x times that of Earth, and has a radius of around 1.19 times that of Earth. It has been estimated that the planet receives about 86% the energy that the Earth receives from the Sun.[6]

It was discovered in early January 2020 by the Transiting Exoplanet Survey Satellite (TESS).

Physical characteristics

Mass, radius and temperature

TOI 700 d is Earth-sized, an exoplanet that has a radius and mass similar to the Earth. It has an estimated mass of around 1.72 M and a radius of about 1.12 R.[2] If it has an earthlike atmosphere, then its average temperature would be about 268.8 K (−4.3 °C; 24.2 °F).[1] A small chance of a runaway greenhouse effect exists.[7]

Host star

Main page: Astronomy:TOI 700

TOI 700 is a red dwarf of spectral class M that is about 40% the mass, about 40% the radius, and very roughly 50% of the temperature of the Sun.[5] 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.[2]

Orbit

TOI 700 d orbits its host star every 37.4260 days.

Proposed habitability

An artist's impression of TOI 700 d, depicted here as a possible ocean planet. The actual appearance of the planet is not known.

TOI 700 d orbits in the habitable zone of its host star TOI 700. The solar wind ram pressure and intensity of the interplanetary magnetic field are expected to be similar to the Earth's, therefore retention of planetary atmosphere is likely.[8][9]

History and discovery

TOI 700 d was discovered by the Transiting Exoplanet Survey Satellite (TESS) in early January 2020. This was the first Earth-sized exoplanet discovered by the TESS.[10] File:NASA-TESS-FirstEarthSizeExoplanetInHabitableZone-TOI700d-20200106.webm

See also


References

  1. 1.0 1.1 1.2 Rodriguez, Joseph E.; Vanderburg, Andrew; Zieba, Sebastian; Kreidberg, Laura; Morley, Caroline V.; Kane, Stephen R.; Spencer, Alton; Quinn, Samuel N. et al. (2020-01-03). "The First Habitable Zone Earth-Sized Planet from TESS. II: Spitzer Confirms TOI-700 d". The Astronomical Journal 160 (3): 117. doi:10.3847/1538-3881/aba4b3. Bibcode2020AJ....160..117R. 
  2. 2.0 2.1 2.2 2.3 Gilbert, Emily A.; Barclay, Thomas; Schlieder, Joshua E.; Quintana, Elisa V.; Hord, Benjamin J.; Kostov, Veselin B.; Lopez, Eric D.; Rowe, Jason F. et al. (2020-01-03). "The First Habitable Zone Earth-sized Planet from TESS. I: Validation of the TOI-700 System". The Astronomical Journal 160 (3): 116. doi:10.3847/1538-3881/aba4b2. Bibcode2020AJ....160..116G. 
  3. Andreolo, Claire; Cofield, Calla; Kazmierczak, Jeanette (6 January 2020). "NASA Planet Hunter Finds Earth-Size Habitable-Zone World". NASA. https://www.jpl.nasa.gov/news/news.php?feature=7569. Retrieved 6 January 2020. 
  4. Garner, Rob (6 January 2020). "NASA Planet Hunter Finds Earth-Size Habitable-Zone World". NASA. https://www.nasa.gov/feature/goddard/2020/nasa-planet-hunter-finds-its-1st-earth-size-habitable-zone-world. Retrieved 6 January 2020. 
  5. 5.0 5.1 Wall, Mike (6 January 2020). "NASA's TESS Planet Hunter Finds Its 1st Earth-Size World in 'Habitable Zone'". Space.com. https://www.space.com/nasa-tess-first-earth-size-habitable-exoplanet-toi-700d.html. Retrieved 6 January 2020. 
  6. "[VIDEO TOI 700d : une planète de la taille de la Terre découverte dans une "zone habitable""] (in fr). https://www.midilibre.fr/2020/01/07/toi-700d-une-planete-de-la-taille-de-la-terre-decouverte-dans-une-zone-habitable,8645004.php. 
  7. Suissa, Gabrielle; Wolf, Eric T.; Kopparapu, Ravi Kumar; Villanueva, Geronimo L.; Fauchez, Thomas; Mandell, Avi M.; Arney, Giada; Gilbert, Emily A. et al. (2020-07-01). "The First Habitable Zone Earth-sized Planet from TESS. III: Climate States and Characterization Prospects for TOI-700 d". The Astronomical Journal 160 (3): 118. doi:10.3847/1538-3881/aba4b4. Bibcode2020AJ....160..118S. 
  8. Cohen, O.; Garraffo, C.; Moschou, S.; Drake, J.; Alvarado-Gomez, J.; Glocer, A.; Fraschetti, F. (2020). "The Space Environment and Atmospheric Joule Heating of the Habitable Zone Exoplanet TOI 700 D". The Astrophysical Journal 897 (1): 101. doi:10.3847/1538-4357/ab9637. Bibcode2020ApJ...897..101C. 
  9. Dong, Chuanfei; Jin, Meng; Lingam, Manasvi (2020). "Atmospheric Escape from TOI-700 d: Venus versus Earth Analogs". The Astrophysical Journal 896 (2): L24. doi:10.3847/2041-8213/ab982f. Bibcode2020ApJ...896L..24D. 
  10. "NASA's TESS Planet Hunter Finds Its 1st Earth-Size World in 'Habitable Zone'". 7 January 2020. https://www.space.com/nasa-tess-first-earth-size-habitable-exoplanet-toi-700d.html. 

External links

Coordinates: Sky map 06h 28m 22.97s, −65° 34′ 43.01″