K2-155d

Last updated
K2-155d
Discovery
Discovered by Teruyuki Hirano et al. [1]
Discovery site Tokyo Institute of Technology
Discovery dateMarch 2018
Transit method
Designations
LP 415-17 c, EPIC 210897587 c [2]
Orbital characteristics
0.1886 (± 0.0066) [3] AU
Eccentricity unknown
40.6835 (± 0.0031) [3] d
Inclination unknown
StarK2-155
Physical characteristics
1.64 +0.18
−0.17 [3] R🜨
Mean density
5.41±1.11  g/cm3
Temperature 289 K (16 °C; 61 °F) [4]

    K2-155d is a potentially habitable Super-Earth exoplanet in the K2-155 system. [5] It is the outermost of three known planets orbiting around the K-type star K2-155 in the constellation Taurus, approximately 290 light years (90 parsecs) from Earth. [6] It is one of 15 new exoplanets around red dwarf stars discovered by Japanese astronomer Teruyuki Hirano of the Tokyo Institute of Technology and his team. [1] The team used data from NASA's Kepler Space Telescope during its extended K2 "Second Light" mission. K2-155d orbits near the so-called habitable zone of its system, and has the potential to host liquid water. [7] [5]

    Contents

    Discovery and observations

    K2-155d is one of 15 exoplanets discovered by a team of Japanese astronomers led by Teruyuki Hirano at the Tokyo Institute of Technology. [5] Its discovery is based on data from the K2 mission of NASA's Kepler spacecraft. [5] The exoplanet has also been observed from ground-based telescopes including the Nordic Optical Telescope (NOT) in La Palma and the Subaru Telescope in Hawaii. [5] Its characteristics were confirmed using speckle imaging and high-dispersion optical spectroscopy. [3] The mass of K2-155d and the brightness of its host star may be measured by future observations from the W. M. Keck Observatory and the James Webb Space Telescope. [3] The brightness of its host star makes K2-155d a good target for future studies using instruments such as the James Webb Space Telescope. [3]

    Characteristics

    K2-155d is a super-Earth exoplanet with a radius 1.64 times that of Earth, near the transition zone between small rock-based and larger gaseous planets. [8] [3] [7] Climate models predict that it is located near its star's habitable zone and has an insolation 1.67 ± 0.38 (between 1.29 and 2.05) times that of Earth. [3] Its physical temperature is estimated to be 289 K (16 degrees Celsius or 61 degrees Fahrenheit). [4] Studies have shown that the planet would maintain a moderate surface temperature if its insolation is smaller than ~1.5 times that of Earth. [3]

    K2-155d is one of three known planets in the system orbiting K2-155, a red dwarf star located 62.3 parsecs (203 ly) from Earth. [3] Its parent star has 88% less volume than the Sun. [9] K2-155d orbits its star with a 40.7 day period, but as the planet is tidally locked the same side always faces its sun. [5] K2-155d has an orbital radius of 0.1886 AU [8] and studies suggest that the planet has a low orbital eccentricity. [10]

    Potential habitability

    K2-155d has been labeled a potentially habitable planet that may be able to harbor liquid water. [7] [5] A three-dimensional climate simulation was used to confirm the possibility of the existence of water. [5] However, its discoverer Teruyuki Hirano was cautious about the findings, stating that they do not guarantee K2-155d is habitable, as the ranges in its orbit and temperature allow the possibility of it being outside the habitable zone. [7] Factors such as the absence of solar flares could also decide if K2-155d is habitable. [5]

    Size comparison of the planet K2-155 d (artistic concept) with Earth K2-155d.jpg
    Size comparison of the planet K2-155 d (artistic concept) with Earth

    References

    1. 1 2 "15 new planets confirmed around cool dwarf stars". Tokyo Tech News. March 12, 2018.
    2. ↑ "The Extrasolar Planet Encyclopaedia — K2-155 d". Extrasolar Planets Encyclopaedia . Retrieved 2024-04-29.
    3. 1 2 3 4 5 6 7 8 9 10 Hirano, Teruyuki; et al. (March 2018). "K2-155: A Bright Metal-poor M Dwarf with Three Transiting Super-Earths". The Astronomical Journal . 155 (3): 11. arXiv: 1801.06957 . Bibcode:2018AJ....155..124H. doi: 10.3847/1538-3881/aaaa6e . S2CID   73590567. 124.
    4. 1 2 "HEC: Exoplanets Calculator (K2-155d)". Planetary Habibility Laboratory. Archived from the original on 2017-08-24. Retrieved 2018-03-30.
    5. 1 2 3 4 5 6 7 8 9 Mack, Eric (March 13, 2018). "A super-Earth around a red star could be wet and wild". CNET .
    6. ↑ "K2-155 PLANET HOST OVERVIEW PAGE". NASA Exoplanet Archive.
    7. 1 2 3 4 Dovey, Dana (March 14, 2018). "Super Earth 200 Light-Years Away May Hold Ideal Temperatures For Liquid Water And Life". Newsweek .
    8. 1 2 "Confirmed Planet Overview Page: K2-155d". NASA Exoplanet Archive. 2018.
    9. ↑ "K2-155d". Exoplanet Data Explorer. 2018. Archived from the original on 2018-03-22. Retrieved 2018-03-21.
    10. ↑ Eylen, Vincent; Albrecht, Simon (May 11, 2015). "Eccentricity from transit photometry: small planets in Kepler multi-planet systems have low eccentricities". The Astrophysical Journal. 808 (2): 126. arXiv: 1505.02814 . Bibcode:2015ApJ...808..126V. doi:10.1088/0004-637X/808/2/126. S2CID   14405731.
    This page is based on this Wikipedia article
    Text is available under the CC BY-SA 4.0 license; additional terms may apply.
    Images, videos and audio are available under their respective licenses.