Author: exoplanetkyo

Kepler 442 b

<Imaginary Picture of Kepler-442 b     Credit:  M Masada, SGH Moriyama High School>

Kepler-442b orbits a red dwarf star that is smaller and cooler than our sun.

The exoplanet completes one orbit every 112 days and gets about two-thirds as much light as Earth. Scientists give it a 97 percent chance of being in the habitable zone.

Kepler-442b is 1,100 light-years away and about one-third larger than Earth; its chance of being rocky is 60 percent.

The host star Kepler 442 has an apparent magnitude of 15.3, with an absolute magnitude of 7.63. It is 0.61 times more massive and 0.60 times larger than our sun. The surface temperature is 4402 K with a spectral type of K5. The exoplanet Kepler-442 b orbits around the star Kepler 442 at an orbital distance of 0.4090.

Journal Articles

1.) VALIDATION OF TWELVE SMALL KEPLER TRANSITING PLANETS IN THE HABITABLE ZONE

2.) Exosolar photovoltaics: Exploring the detailed balance of other star and planetary systems

 

WEB Articles

1.) Kepler-442b is more habitable than Earth

2.) Kepler-438b and 442b: Are These the Planets We’re Looking For?

3.) HIRAETH: KEPLER-442B

Kepler 438 b

Discovered in January 2015, Kepler-438b looked like an excellent candidate for a habitable planet. The planet fits the two key characteristics for a Kepler candidate to a T. The first of these is that the planet has to be rocky, like Earth or Mars, rather than gaseous, like Jupiter or Saturn. The second is that it has to orbit its star in the habitable zone, where temperatures are neither too hot nor too cold to support life.

Kepler-438b It is only 12 percent bigger than Earth and receives about 40 percent more light. Kepler-438b is similar in temperature to the Earth, but it is much closer to its star, a cooler Red Dwarf called Kepler-438. Kepler-438b orbits Kepler-438 every 35 days.

The research team, led by David Armstrong of the University of Warwick’s Astrophysics Group, has discovered that this star is very active, shooting superflares and associated coronal mass ejections every few hundred days. Using photometry, the team detected excess radiation caused by the star’s flares.

The coronal mass ejections from the star, 10 times more powerful than any on record made by our sun, may have stripped the planet of its atmosphere.

Kepler 438 b orbits the star Kepler 438, which is located 472.9 (145 parsecs) away from our solar system. Its apparent magnitude is 15 and its absolute magnitude is 9.2. It is 0.5 times the mass and 0.5 times the radius of our sun, it is also an M1 type star, at 3748 degrees kelvin.

Kepler-438系は、こと座に位置し地球から約470光年の位置にある惑星系で、主星はK型主系列星(温度3748K、質量0.54太陽質量、半径0.62太陽半径)に分類されます。星の年齢は約44億歳と考えられていて、太陽とほぼ同年齢です。なお、この星は磁気活動が強く、Kepler宇宙望遠鏡の測光観測データの解析からスーパーフレアが多数観測されています。 この系では2015年1月にKepler宇宙望遠鏡のトランジット観測により、惑星Kepler-438bが発見されました。Kepler-438bは、軌道周期が35日、半径が1.12地球半径・1.3地球半径であり、惑星の表面に液体の水が存在できるハビタブルゾーン内に存在する岩石惑星の可能性がかなり高いと考えられています。一方で前述の様にこの系の主星は超巨大なフレア(スーパーフレア)を頻発しているため、大気中に強い紫外線・放射線が降り注いだり、フレアに付随するコロナ質量放出衝突で放出されたガス・プラズマが大気衝突に頻繁に衝突する事が考えられ、大気散逸過程や詳細なはビタビリティに関しては、今後の詳しい観測・理論研究が大変重要と考えられます。

論文:https://academic.oup.com/mnras/article-lookup/doi/10.1093/mnras/stv2419

ジャーナル記事

1.) VALIDATION OF TWELVE SMALL KEPLER TRANSITING PLANETS IN THE HABITABLE ZONE

2.) Where are they?

 

WEB記事

1.) Farewell to hope of life on Kepler-438b

2.) Kepler-438b and 442b: Are These the Planets We’re Looking For?

3.) Could Humans Survive On Kepler-438b?

Kepler 296 e

Kepler-296 e is a Super-Earth exoplanet that orbits a K-type star. It is located 1820.0 light-years (558 parsecs) from our solar system and was discovered in 2014 orbiting its host star Kepler-296. The apparent magnitude of the host star is 13.4 and the absolute magnitude is 4.7. Kepler-296 is about 1.1 the mass of our sun and has about 0.6 the radius. Its surface temperature is 4249 K and is a spectral K6 type star. The planet Kepler-296 e orbits the star every 34.1 days, it’s orbital radius is 0.17 SEAU.

 

Journal Articles

1.) VALIDATION OF TWELVE SMALL KEPLER TRANSITING PLANETS IN THE HABITABLE ZONE

2.) THE FIVE PLANETS IN THE KEPLER-296 BINARY SYSTEM ALL ORBIT THE PRIMARY: A STATISTICAL

AND ANALYTICAL ANALYSIS

WEB Articles

1.) Kepler-296 e

Kepler-296 f

Kepler-296 f is located 1820 light-years (558 parsecs) from our solar system and was discovered in 2014 orbiting its host star Kepler-296. The apparent magnitude of the host star is 13.4 and the absolute magnitude is 4.7. Kepler-296 is about 1.0 the mass of our sun and has about 0.6 the radius. Its surface temperature is 4249 K and is a spectral K6 type star. The planet Kepler-296 f orbits the star every 63.3 days, it’s orbital radius is 0.26 SEAU.

Kepler-440 b

Kepler-440 b is located 851.3 light-years (261 parsecs) from our solar system and was discovered in 2015 orbiting its host star Kepler-440. The apparent magnitude of the host star is 15.5 and the absolute magnitude is 8.4. Kepler-440 is about 0.6 the mass of our sun and has about 0.6 the radius. Its surface temperature is 4134 K and is a spectral K6 type star. The planet Kepler-440 b orbits the star every 101.1 days, it’s orbital radius is 0.24 SEAU.

Kepler-560 b

Kepler-560 b is located 287.0 light-years (88.0 parsecs) from our solar system and was discovered in 2016 orbiting its host star Kepler-560. The apparent magnitude of the host star is 12.3 and the absolute magnitude is 7.6. Kepler-560 is about 0.3 the mass of our sun and has about 0.3 the radius. Its surface temperature is 3556 K and is a spectral M3 type star. The planet Kepler-560 b orbits the star every 18.5 days, it’s orbital radius is 0.10 SEAU.