Kepler-438b
Discovery date | 2015[4] |
---|---|
Transit | |
Orbital characteristics | |
0.16600 AU (24,833,000 km) | |
Eccentricity | 0.03+0.01 −0.03[3] |
35.23319 d | |
Inclination | 89.860 |
Star | Kepler-438 |
Physical characteristics | |
Mean radius | 1.12 (± 0.16) R🜨 |
Temperature | 276 K (3 °C; 37 °F) |
Kepler-438b (also known by its
Characteristics
Mass, radius and temperature
Kepler-438b is an
Host star
The planet orbits a (M-type) red dwarf star named Kepler-438. The star has a mass of 0.54 M☉ and a radius of 0.52 R☉, both lower than those of the Sun by almost half. It has a surface temperature of 3748 K and is estimated to be about 4.4 billion years old,[3] only 200 million years younger than the Sun[7] and the Sun has a surface temperature of 5778 K.[8]
The star's apparent magnitude, or how bright it appears from Earth's perspective, is 14.467. Therefore, it is too dim to be seen with the naked eye.
Orbit and possible moons
Kepler-438b orbits its parent star once every 35 days and 5 hrs[1][2] It is likely tidally locked due to its close distance to its star.[9] A search for exomoons by the Hunt for Exomoons with Kepler project around Kepler-438b placed a maximum mass of a hypothetical moon at 29% that of the planet.[10]
Habitability
The planet was announced as orbiting within the
Researchers at the University of Warwick say that Kepler-438b is not habitable due to the large amount of radiation it receives.[12] The question of what makes a planet habitable is much more complex than having a planet located at the right distance from its host star so that water can be liquid on its surface: various geophysical and geodynamical aspects, the radiation, and the host star's plasma environment can influence the evolution of planets and life, if it originated.[13] The planet is more likely to resemble a larger and cooler version of Venus.
Discovery and follow-up studies
In 2009,
At nearly 460 light-years (140 pc) distant, Kepler-438b is too far from Earth for either current telescopes, or even the next generation of planned telescopes, to accurately determine its mass or whether it has an atmosphere. The Kepler spacecraft can only focus on a small, fixed region of the sky, but the next generation of planet-hunting space telescopes, such as
Kepler Space Telescope
|
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Confirmed small exoplanets in habitable zones.
(Kepler-62e, Kepler-62f, Kepler-186f, Kepler-296e, Kepler-296f, Kepler-438b, Kepler-440b, Kepler-442b) (Kepler Space Telescope; 6 January 2015).[1] |
See also
References
- ^ a b c d e f Clavin, Whitney; Chou, Felicia; Johnson, Michele (6 January 2015). "NASA's Kepler Marks 1,000th Exoplanet Discovery, Uncovers More Small Worlds in Habitable Zones". NASA. Retrieved 6 January 2015.
- ^ a b c Sample, Ian (7 January 2015). "Kepler 438b: Most Earth-like planet ever discovered could be home for alien life". The Guardian. Retrieved 7 January 2015.
- ^ S2CID 8512655.
- ^ Staff (2015). "Planet Kepler-438 b". Extrasolar Planets Encyclopaedia. Retrieved 11 January 2015.
- ^ Northon, Karen (19 March 2015). "NASA's Kepler Uncovers More Small Worlds in Habitable Zones". NASA. Retrieved 29 December 2022.
- ^ Gilster, Paul (6 January 2015). "AAS: 8 New Planets in Habitable Zone". Centauri-dreams.org. Retrieved 9 January 2015.
- ^ Fraser Cain (16 September 2008). "How Old is the Sun?". Universe Today. Retrieved 19 February 2011.
- ^ Fraser Cain (15 September 2008). "Temperature of the Sun". Universe Today. Retrieved 19 February 2011.
- ^ "Kepler-438b: Astronomers Find Most Earth-Like Exoplanet Yet". Sci News. 8 January 2015. Retrieved 13 June 2016.
- S2CID 119305398.
- ISSN 0036-8075.
- ^ 'Earth-like' Exoplanet Likely Not Habitable
- S2CID 123220355. Archived from the original(PDF) on 2 June 2016. Retrieved 3 May 2016.
- S2CID 119302350.