Kepler-62d
{{Short description|Super-Earth orbiting Kepler-62}}
{{Infobox planet
| name = Kepler-62d
| discoverer = Borucki et al.
| discovery_site = Kepler Space Observatory
| discovery_method = Transit (Kepler Mission)
| apsis = astron
| semimajor = 0.120 ± 0.001 AU
| period = 18.16406 ± 0.00002 d
| star = Kepler-62 (KOI-701)
| mean_radius = 1.95 ± 0.07 {{Earth radius|link=y}}
| mass = {{val|5.5|8.5|5.5}}[http://phl.upr.edu/press-releases/nasakeplerdiscoversnewpotentiallyhabitableexoplanets NASA Kepler Discovers New Potentially Habitable Exoplanets] {{Webarchive|url=https://web.archive.org/web/20191021202324/http://phl.upr.edu/press-releases/nasakeplerdiscoversnewpotentiallyhabitableexoplanets |date=2019-10-21 }} Abel Mendez. April 18, 2013. Retrieved August 10, 2016. {{Earth mass|sym=y|link=y}}
| single_temperature = Teq: {{convert|510|K|C F}}
}}
Kepler-62d (also known by its Kepler Object of Interest designation KOI-701.01) is the third innermost and the largest exoplanet discovered orbiting the star Kepler-62, with a size roughly twice the diameter of Earth. It was found using the transit method, in which the dimming that a planet causes as it crosses in front of its star is measured.{{Cite journal | last=Borucki | first=William J. | author-link=William J. Borucki |display-authors=etal | title=Kepler-62: A Five-Planet System with Planets of 1.4 and 1.6 Earth Radii in the Habitable Zone | journal=Science Express| date=18 April 2013 |doi=10.1126/science.1234702 |arxiv = 1304.7387 |bibcode = 2013Sci...340..587B | pmid=23599262 | volume=340 | issue=6132 | pages=587–90| s2cid=21029755 }} Its stellar flux is 15 ± 2 times Earth's. Due to its closer orbit to its star, it is a super-Venus or, if it has a volatile composition, a hot Neptune, with an estimated equilibrium temperature of {{convert|510|K|C F}}, too hot to sustain life on its surface.
Physical characteristics
=Mass, radius and temperature=
Kepler-62d is a super-Earth, an exoplanet with a radius and mass bigger than Earth, but smaller than that of the ice giants Uranus and Neptune. It has an equilibrium temperature of {{convert|510|K|C F}}. It has a radius of 1.95 {{earth radius}}. Because of its radius (and temperature), it is likely to be either a "super-Venus", or a hot mini-Neptune, with no solid surface. However, the mass is currently not known, estimates place an upper limit of 14 {{Earth mass|sym=y}}, the real mass is expected to be lower than this. The true value is likely around 5.5 {{Earth mass|sym=y}}, based on its composition.
=Host star=
{{main|Kepler-62}}
The planet orbits a (K-type) star named Kepler-62, orbited by a total of five planets. The star has a mass of 0.69 {{solar mass|link=y}} and a radius of 0.64 {{solar radius|link=y}}. It has a temperature of 4925 K and is 7 billion years old. In comparison, the Sun is 4.6 billion years old{{cite web |url=http://www.universetoday.com/18237/how-old-is-the-sun/ |title=How Old is the Sun? |author=Fraser Cain |date=16 September 2008 |publisher=Universe Today |access-date=19 February 2011}} and has a temperature of 5778 K.{{cite web |url=http://www.universetoday.com/18092/temperature-of-the-sun/ |title=Temperature of the Sun |author=Fraser Cain |date=15 September 2008 |publisher=Universe Today |access-date=19 February 2011}} The star is somewhat metal-poor, with a metallicity ([Fe/H]) of −0.37, or 42% of the solar amount. Its luminosity ({{solar luminosity|link=y}}) is 21% that of the Sun.
The star's apparent magnitude, or how bright it appears from Earth's perspective, is 13.65. Therefore, it is too dim to be seen with the naked eye.
=Orbit=
Discovery
In 2009, NASA's Kepler spacecraft was completing observing stars on its photometer, the instrument it uses to detect transit events, in which a planet crosses in front of and dims its host star for a brief and roughly regular period of time. In this last test, Kepler observed {{val|50,000}} stars in the Kepler Input Catalog, including Kepler-62; the preliminary light curves were sent to the Kepler science team for analysis, who chose obvious planetary companions from the bunch for follow-up at observatories. Observations for the potential exoplanet candidates took place between 13 May 2009 and 17 March 2012. After observing the respective transits, which for Kepler-62d occurred roughly every 18 days (its orbital period), it was eventually concluded that a planetary body was responsible for the periodic 18-day transits. The discovery, along with the planetary system of the star Kepler-69 were announced on April 18, 2013.
References
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{{Kepler-62}}
{{Exoplanets}}
{{2013 in space}}
{{Sky|18|52|51.06019|+|45|20|59.507}}
Category:Exoplanets discovered in 2013