Kepler-46

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Star
Kepler-46
AladinLite
Observation
dates equinox :  J2000.0 , epoch : J2000.0
Constellation lyre
Right ascension 19 h 17 m 4.5 s
declination + 42 ° 36 ′ 15 ″
Apparent brightness 13,436 likes
Typing
Astrometry
distance 855 +68−65 pc  
Visual absolute brightness M vis 5.18 likes
Physical Properties
Dimensions 0.902 +0.040−0.038 M ☉
radius 0.790 ± 0.441  R ☉
Effective temperature 5309 ± 200  K
Metallicity [Fe / H] 0.41 ± 0.10
Age 9.7 +3.7−3.5Billion  a
Other names
and catalog entries
2MASS catalog 2MASS J19170449 + 4236150 [1]
Other names KOI-872, KIC 7109675, Kepler-46

Kepler-46 (also KOI-872 ) is a star in the constellation Lyra , about 2,788 light years from the Sun. Observed by the Kepler space telescope from 2009 onwards , it has a planetary system with three known exoplanets . Another is suspected. Kepler-46 has a slightly lower mass than the sun (around 90%), but is much older at almost ten billion years.

Kepler-46 b (previously KOI-872.01 ) was discovered in 2012 as the first planet in the system based on detailed analysis of the Kepler data. Another planet, Kepler-46c, was detected by a group of researchers using Kepler data from variations in the transit of planets ( transit timing ). Although this only confirmed one additional planet, there was a possibility that another planet ( KOI-872.03 ) could exist. Subsequent analyzes finally allowed the confirmation of this planet, which was named Kepler-46d .

Planetary system

Kepler-46b is likely a gas planet with approximately six times the mass of Jupiter . The second planet, Kepler-46c, was one of the first exoplanets to be detected by the transit timing method. The discovery could be confirmed with 99% certainty and showed that other exoplanets and possibly exomonde could be discovered in this way in the future. The second planet acts with its gravitational force on the first and orbits its central star in only 34 days. Other planets would influence the orbital time and thus the duration of a transit in front of the star. Thus a planet can be detected even if it does not pass in front of the star as seen from the earth .

According to the data, Kepler-46c is an object of approximately the mass of Saturn with an orbital period of 57 days. Since it is not a transit planet itself, its size cannot be determined. Possibly it corresponds to that of Kepler-46 b. The measurement results also suggest the existence of another planet with an orbital period of around 6.8 days.

The discovery of Kepler-46c is similar to that of the planet Neptune in the solar system . In both cases, the planet was detected by its gravitational influence on an already known planet.

Planetary system from Kepler-46
Planet
(by distance from the star) 		Discovery
(year) 		Radius
(in R ♃ ) 		Mass
(in M ♃ ) 		Cycle time
(in days) 		Major semi-axis
(in AU ) 		eccentricity Orbit inclination
(in ° )
Kepler-46d 2014 0.146 ± 0.082 - 6.766589 ± 0.000022 0.067 - -
Kepler-46b 2012 0.808 +0.042−0.043 <6 33.60134 +0.00021−0.00020 0.1968 + 0.0029−0.0028 0.01 ± 0.01 89.038 +0.075−0.067
Kepler-46c 2012 0.146 ± 0.082 0.376 + 0.021−0.019 57.011 +0.051−0.061 0.2799 +0.051−0.061 0.0146 87.4 +1.6−1.0

Individual evidence

  1. ↑ a b SIMBAD: Kepler-46. Retrieved May 31, 2015 .
  2. ↑ a b c d e f g h i j NASA Exoplanet Archives: Kepler-46. Retrieved May 31, 2015 .
  3. ↑ Nesvorny et al .: The Detection and Characterization of a Nontransiting Planet by Transit Timing Variations . arxiv : 1208.0942 .
  4. ^ Rowe et al .: Validation of Kepler's Multiple Planet Candidates. III: Light Curve Analysis & Announcement of Hundreds of New Multi-planet Systems . arxiv : 1402.6534 .
  5. ↑ a b Space.com of May 10, 2012: Hidden Alien Planet Revealed by Its Own Gravity. Retrieved May 31, 2015 .
  6. ↑ EarthSky of May 12, 2012: New planet found in distant solar system by its tug on another world. Retrieved May 31, 2015 .