6 गृह जहाँ भविष्य है मनुष्य का || 6 Exoplanets Your Descendants Could Colonize || #rtv61
Episode – 61
Tau Ceti (τ Cet, τ Ceti) is a star in the constellation Cetus that is spectrally similar to the Sun, although it has only about 78% of the Sun’s mass. At a distance of just under 12 light-years (3.7 parsecs) from the Solar System, it is a relatively nearby star, and is the closest solitary G-class star.[nb 2] The star appears stable, with little stellar variation, and is metal-deficient.
Kepler-438b (also known by its Kepler Object of Interest designation KOI-3284.01) is a confirmed near-Earth-sized exoplanet, likely rocky, orbiting on the inner edge of the habitable zone of the red dwarf as it receives 1.4 times our solar flux. Kepler-438, about 470 light-years (145 parsecs, or nearly 4.5×1015 km) from Earth in the constellation Lyra. The planet was discovered by NASA’s Kepler spacecraft using the transit method, in which the dimming effect that a planet causes as it crosses in front of its star is measured. NASA announced the confirmation of the exoplanet on 6 January 2015. Although it is not habitable, as of June 2015, it has the highest index on the Earth Similarity Index, with a rating of 0.88. Kepler-438b is approximately 470 light years from Earth.
Gliese 667 (142 G. Scorpii) is a triple-star system in the constellation of Scorpius lying at a distance of about 6.8 pc (23.6 ly) from Earth. All three of the stars have masses smaller than the Sun. There is a 12th magnitude star close to the other three, but it is not gravitationally bound to the system. To the naked eye, the system appears to be a single faint star of magnitude 5.89.
The system has a relatively high proper motion, exceeding 1 second of arc per year.
The two brightest stars in this system, GJ 667 A and GJ 667 B, are orbiting each other at an average angular separation of 1.81 arcseconds with a high eccentricity of 0.58. At the estimated distance of this system, this is equivalent to a physical separation of about 12.6 AU, or nearly 13 times the separation of the Earth from the Sun. Their eccentric orbit brings the pair as close as about 5 AU to each other, or as distant as 20 AU, corresponding to an eccentricity of 0.6.[note 1] This orbit takes approximately 42.15 years to complete and the orbital plane is inclined at an angle of 128° to the line of sight from the Earth. The third star, GJ 667 C, orbits the GJ 667 AB pair at an angular separation of about 30″, which equates to a minimum separation of 230 AU.
Kepler-186f (also known by its Kepler Object of Interest designation KOI-571.05) is an exoplanet orbiting the red dwarf Kepler-186, about 500 light-years (171 parsecs, or nearly 5.298×1015 km) from the Earth. It is the first planet with a radius similar to Earth’s to be discovered in the habitable zone of another star. NASA’s Kepler spacecraft detected it using the transit method, along with four additional planets orbiting much closer to the star (all modestly larger than Earth). Analysis of three years of data was required to find its signal. The results were presented initially at a conference on 19 March 2014 and some details were reported in the media at the time. The public announcement was on 17 April 2014, followed by publication in Science.
Kepler-62f (also known by its Kepler Object of Interest designation KOI-701.04) is a super-Earth exoplanet orbiting within the habitable zone of the star Kepler-62, the outermost of five such planets discovered by NASA’s Kepler spacecraft. It is located about 1,200 light-years (370 parsecs, or nearly 1.135×1016 km) from Earth in the constellation of Lyra. The exoplanet was found by using the transit method, in which the dimming effect that a planet causes as it crosses in front of its star is measured. Kepler-62f may be a terrestrial or ocean-covered planet; it lies within the outer part of its host star’s habitable zone.
Kapteyn b is a possible exoplanet that orbits within the habitable zone of the red subdwarf Kapteyn’s star, located approximately 12.8 light-years (3.92 pc) from Earth. Kapteyn b is within the estimated habitable zone of its star. It was the closest suspected potentially habitable exoplanet to the Solar System other than Tau Ceti e up until 2016, when Proxima Centauri b at 4.22 light-years was confirmed. However, later research has cast doubt on the existence of Kapteyn b, suggesting the signal is consistent with stellar activity rather than a planet.
The system itself is estimated to be 11 billion years old, substantially older than the Solar System.
Music – Heart of Nowhere Kevin MacLeod (incompetech.com)
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