Astronomy:GJ 1132 b

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Short description: Terrestrial exoplanet orbiting GJ 1132
GJ 1132 b
Exoplanet Comparison GJ 1132 b.png
Size comparison of GJ 1132 b with Earth.
Discovery[3]
Discovered byMEarth-South Array Team
Discovery siteChile
Discovery dateMay 10, 2015 (announced)[1] November 12, 2015 (confirmed)[2]
Transit
Orbital characteristics[6]
0.0153±0.0005 astronomical unit|AU
Eccentricity<0.22
Orbital period1.6289304(13) d[4]
Inclination86.58°±0.63°[5]
Semi-amplitude2.85±0.34 m/s
StarGJ 1132
Physical characteristics[6]
Mean radius1.130±0.056 R
Mass1.66±0.23 M
Mean density6.3±1.3 g/cm3
12.9±2.2 m/s2
13.6±1.0 km/s


GJ 1132 b (also known as Gliese 1132 b) is an exoplanet orbiting the red dwarf star GJ 1132 41 light-years (13 parsecs) from Earth,[3] in the constellation Vela. The planet is considered uninhabitable but cool enough to possess an atmosphere.[1] GJ 1132 b was discovered by the MEarth-South array in Chile.[7]

It has been called "one of the most important planets ever discovered beyond the Solar System": Due to its relative proximity to Earth, telescopes should be able to determine the composition of its atmosphere, the speed of its winds and the color of its sunsets.[8][9][10] This is due in part to the small diameter of its parent star (20% that of the Sun), which increases the effect on the star's light of its transits. The planet's diameter is approximately 20% larger than that of the Earth[3] and its mass is estimated at 1.6 times that of Earth,[1] implying that it has an Earth-like rocky composition.[11] GJ 1132 b orbits its star every 1.6 days at a distance of 1.4 million miles (2.24 million kilometres).[7]

The planet receives 19 times more stellar radiation than Earth.[3] The equilibrium temperature is estimated at 529 K (256 °C; 493 °F) for an Earth-like albedo, or 409 K (136 °C; 277 °F) for a Venus-like albedo. The planet is likely to be hotter than Venus, as higher temperatures likely prevail at the surface if the planet has an atmosphere.[11] It is possible that the night side of the planet is cooler, because it is presumed to be tidally locked due to its proximity to its star; however, under most circumstances where an atmosphere is thick, it would be able to transfer heat to the far side.

Atmosphere

In April 2017, a hydrogen-dominated atmosphere was claimed to have been detected around GJ 1132 b.[12][5] However, subsequent, more precise work ruled out the claim.[13] Instead, in 2021 detection of a hazy hydrogen atmosphere without helium but with the admixture methane and hydrogen cyanide (implying substantial underlying free nitrogen in the mix, at around 8.9% of the atmosphere) was claimed.[14] However, two subsequent studies found no evidence for molecular absorption in the HST WFC3 Spectrum of GJ 1132 b. Instead, the spectrum was found to be flat,[15][16] which is more consistent with our current understanding of photoevaporation.

Gallery

See also

References

  1. 1.0 1.1 1.2 Chu, Jennifer (November 11, 2015). "New exoplanet in our neighborhood". MIT News. https://news.mit.edu/2015/new-earth-sized-exoplanet-1111. 
  2. NASA Exoplanet Archive New ticker slide 1
  3. 3.0 3.1 3.2 3.3 Berta-Thompson, Zachory K. et al. (2015). "A rocky planet transiting a nearby low-mass star". Nature 527 (7577): 204–207. doi:10.1038/nature15762. PMID 26560298. Bibcode2015Natur.527..204B. 
  4. Kokori, A. et al. (14 February 2023). "ExoClock Project. III. 450 New Exoplanet Ephemerides from Ground and Space Observations". The Astrophysical Journal Supplement Series 265 (1). doi:10.3847/1538-4365/ac9da4. Bibcode2023ApJS..265....4K.  Vizier catalog entry
  5. 5.0 5.1 Southworth, John et al. (2017). "Detection of the Atmosphere of the 1.6 M🜨 Exoplanet GJ 1132 b". The Astronomical Journal 153 (4): 191. doi:10.3847/1538-3881/aa6477. Bibcode2017AJ....153..191S. 
  6. 6.0 6.1 Bonfils, X. et al. (October 2018), "Radial velocity follow-up of GJ1132 with HARPS. A precise mass for planet 'b' and the discovery of a second planet", Astronomy & Astrophysics 618: 12, doi:10.1051/0004-6361/201731884, A142, Bibcode2018A&A...618A.142B. 
  7. 7.0 7.1 "Astronomers Eager to Get a Whiff of Newfound Venus-like Planet". Harvard–Smithsonian Center for Astrophysics. November 11, 2015. https://www.cfa.harvard.edu/news/2015-24. 
  8. Sample, Ian (11 November 2015). "Earth-like world could be 'most important planet found outside solar system'". https://www.theguardian.com/science/2015/nov/11/earth-like-world-gj1132b-could-be-most-important-planet-ever-found-outside-the-solar-system. 
  9. Burgess, Matt. "Exoplanet GJ 1132b: the 'most important' ever found". Wired UK. https://www.wired.co.uk/news/archive/2015-11/12/gj-1132b-most-important-planet-solar-system. Retrieved 2015-11-12. 
  10. "Getting Up Close and Personal with an Earth-Sized Exoplanet". The Kavli Foundation. November 11, 2015. http://www.kavlifoundation.org/science-spotlights/getting-close-and-personal-earth-sized-exoplanet#.VkYmYeSFMY8. 
  11. 11.0 11.1 Eva Botkin-Kowacki (2015-11-11). "Spotted: A rocky Earth-sized planet close by". The Christian Science Monitor. http://www.csmonitor.com/Science/2015/1111/Spotted-A-rocky-Earth-sized-planet-close-by. 
  12. "Atmosphere around super-Earth detected". April 6, 2017. https://phys.org/news/2017-04-atmosphere-super-earth.html. 
  13. Diamond-Lowe, Hannah et al. (2018). "Ground-based Optical Transmission Spectroscopy of the Small, Rocky Exoplanet GJ 1132b". The Astronomical Journal 156 (2). doi:10.3847/1538-3881/aac6dd. Bibcode2018AJ....156...42D. 
  14. Swain, Mark R.; Estrela, Raissa; Roudier, Gael M.; Sotin, Christophe; Rimmer, Paul B.; Valio, Adriana; West, Robert; Pearson, Kyle et al. (2021). "Detection of an Atmosphere on a Rocky Exoplanet". The Astronomical Journal 161 (5): 213. doi:10.3847/1538-3881/abe879. Bibcode2021AJ....161..213S. 
  15. Mugnai, Lorenzo V.; Modirrousta-Galian, Darius; Edwards, Billy; Changeat, Quentin; Bouwman, Jeroen; Morello, Giuseppe; Al-Refaie, Ahmed; Baeyens, Robin et al. (2021-04-05). "ARES.* V. No Evidence for Molecular Absorption in the HST WFC3 Spectrum of GJ 1132 b". The Astronomical Journal 161 (6): 284. doi:10.3847/1538-3881/abf3c3. Bibcode2021AJ....161..284M. 
  16. Libby-Roberts, Jessica E.; Berta-Thompson, Zachory K.; Diamond-Lowe, Hannah; Gully-Santiago, Michael A.; Irwin, Jonathan M.; Kempton, Eliza M.-R.; Rackham, Benjamin V.; Charbonneau, David et al. (2022). "The Featureless HST/WFC3 Transmission Spectrum of the Rocky Exoplanet GJ 1132b: No Evidence for a Cloud-free Primordial Atmosphere and Constraints on Starspot Contamination". The Astronomical Journal 164 (2): 59. doi:10.3847/1538-3881/ac75de. Bibcode2022AJ....164...59L. 
  17. "Hubble Sees New Atmosphere Forming on a Rocky Exoplanet". https://esahubble.org/news/heic2104/. 

Coordinates: Sky map 10h 14m 51.100s, −47° 09′ 12.00″