CoRoT-7 b

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Size comparison: Earth, CoRot-7b and Neptune
artist's impression of CoRot-7b

CoRoT-7 b , previously called CoRoT-Exo-7 b , is the name of an exoplanet in the constellation Unicorn . With a diameter of around 20,000 kilometers, it was one of the smallest known exoplanets when it was discovered in 2009. CoRoT-7 b is an ultra-short period planet .

properties

CoRoT-7b has a diameter of around 20,000 kilometers (approx. 1.7 Earth diameter or approx. 0.136 Jupiter diameter ) and was discovered in January 2009 as the seventh exoplanet candidate with the help of the CoRoT space telescope.

The planet is about 150 parsecs (about 490 light years ) away from Earth and accompanies its central star CoRoT-7 at a distance of about 2.55 million kilometers (about 0.017 AU ). The exoplanet only needs about 20 hours to orbit its star.

After the mass of CoRoT-7 b was initially estimated to be around 11 Earth masses (approx. 0.035 M J ), more precise measurements (with the participation of the Thuringian State Observatory), taking into account the newly discovered neighboring planet CoRoT-7 c , revealed that CoRoT-7 b was one of the lowest-mass exoplanets discovered at 4.8 Earth masses. Since the diameter of CoRoT-7b is also relatively small, it is counted among the so-called super - earths .

The surface temperature is estimated to be over 1300 Kelvin (~ 1000  degrees Celsius ) due to the short distance to the central  star . According to a simulation by Washington University in St. Louis , the atmosphere consists primarily of sodium , potassium , silicon monoxide and oxygen . Components of the rock evaporated by the high heat make up a smaller proportion: magnesium , aluminum , calcium and iron . It is assumed that these substances condense in higher atmospheric layers and that it therefore "rains" pebbles on CoRoT-7b.

The central star

→ Main article: CoRoT-7

The star CoRoT-7 is a main sequence star of the spectral type K0 with an apparent magnitude of 11.7 magnitudes. With a surface temperature of around 5300 Kelvin, it is similar to the sun .

Individual evidence

  1. ↑ a b c CoRoT-7 b (English) - Entry in Extrasolar Planets Encyclopaedia
  2. ↑ Rainer Kayser: cloudy weather with rain of pebbles. In: astronews.com. October 26, 2009. Retrieved November 3, 2009 .

See also

Web links