Kepler-1229b (also known by its Kepler Object of Interest designation ''KOI-2418.01'') is a confirmed super-Earth

exoplanet An exoplanet or extrasolar planet is a planet outside the Solar System. The first possible evidence of an exoplanet was noted in 1917 but was not recognized as such. The first confirmation of detection occurred in 1992. A different planet, init ...

, likely rocky, orbiting within the habitable zone of the

red dwarf ''Red Dwarf'' is a British science fiction comedy franchise created by Rob Grant and Doug Naylor, which primarily consists of a television sitcom that aired on BBC Two between 1988 and 1999, and on Dave since 2009, gaining a cult following. T ...

Kepler-1229 Kepler-1229 is a red dwarf star located about away from the Earth in the constellation of Cygnus. It is known to host a super-Earth exoplanet within its habitable zone, Kepler-1229b, which was discovered in 2016. Nomenclature and h ...

, located about 870

light year A light-year, alternatively spelled light year, is a large unit of length used to express astronomical distances and is equivalent to about 9.46 trillion kilometers (), or 5.88 trillion miles ().One trillion here is taken to be 1012 ...

s (267 parsecs) from Earth in the constellation of Cygnus. It was discovered in 2016 by the '' Kepler'' space telescope.1st Alien Earth Still Elusive Despite Huge Exoplanet Haul
Mike Wall, ''Space.com'' 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.

Physical characteristics

Mass, radius and temperature

Kepler-1229b is likely a rocky super-Earth, an exoplanet with a radius and mass bigger than Earth, but smaller than that of the gas giants

Neptune Neptune is the eighth planet from the Sun and the farthest known planet in the Solar System. It is the fourth-largest planet in the Solar System by diameter, the third-most-massive planet, and the densest giant planet. It is 17 times ...

and Uranus. It is 2.7 times the mass of earth. It has an equilibrium temperature of .

Host star

The planet orbits a ( M-type)

star A star is an astronomical object comprising a luminous spheroid of plasma (physics), plasma held together by its gravity. The List of nearest stars and brown dwarfs, nearest star to Earth is the Sun. Many other stars are visible to the naked ...

named

, orbited by a total of one planet. The star has a mass of 0.54 and a radius of 0.51 . It has a temperature of 3724 K and is about 3.72 billion years old. In comparison, the Sun is 4.6 billion years old and has a temperature of 5778 K. The star's apparent magnitude, or how bright it appears from Earth's perspective, is 15.474. Therefore, it is too dim to be seen with the naked eye.

Orbit

Kepler-1229b orbits its host star with about 4% of the Sun's luminosity every 86.829 days at a distance of (close to that of

Mercury Mercury commonly refers to: * Mercury (planet), the nearest planet to the Sun * Mercury (element), a metallic chemical element with the symbol Hg * Mercury (mythology), a Roman god Mercury or The Mercury may also refer to: Companies * Merc ...

, which orbits at a distance of 0.387 AU).

Habitability

The exoplanet, along with eight others, was announced to be orbiting in the habitable zone of its parent star, the region where, with the correct conditions and atmospheric properties, liquid water may exist on the surface of the planet. Kepler-1229b has a radius of 1.4 , so it is likely rocky. Its host star is a

, with about half as much mass than the Sun does. As a result, stars like Kepler-1229 have the ability to live up to 50–60 billion years, 5–6 times longer than the Sun will live. The planet is likely tidally locked, with one side of its hemisphere permanently facing towards the star, while the opposite side shrouded in eternal darkness. However, between these two intense areas, there would be a sliver of habitability – called the

terminator line A terminator or twilight zone is a moving line that divides the daylit side and the dark night side of a planetary body. The terminator is defined as the locus of points on a planet or moon where the line through the center of its parent star i ...

, where the temperatures may be suitable (about ) for liquid water to exist. Additionally, a much larger portion of the planet may be habitable if it supports a thick enough atmosphere to transfer heat to the side facing away from the star.

Discovery and follow-up studies

In 2013, before the two wheels failed, 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 near-regular period of time. In this last test, Kepler observed stars in the Kepler Input Catalog, including Kepler-1229; 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. The radial velocity observations confirmed that a planetary body was responsible for the dips observed in Kepler-1229's light curve, thus confirming it as a planet. The planet was then announced in the newest catalog released by NASA on May 12, 2016, about 3 years later. At nearly distant, Kepler-1229b is too remote and its star too far for current telescopes or the next generation of planned telescopes to determine its mass or whether it has an atmosphere. The Kepler spacecraft focused on a single small region of the sky but next-generation planet-hunting space telescopes, such as TESS and CHEOPS, will examine nearby stars throughout the sky. Nearby stars with planets can then be studied by the upcoming

James Webb Space Telescope The James Webb Space Telescope (JWST) is a space telescope which conducts infrared astronomy. As the largest optical telescope in space, its high resolution and sensitivity allow it to view objects too old, distant, or faint for the Hubble Spa ...

and future large ground-based telescopes to analyze atmospheres, determine masses and infer compositions. Additionally the Square Kilometer Array would significantly improve radio observations over the

Arecibo Observatory The Arecibo Observatory, also known as the National Astronomy and Ionosphere Center (NAIC) and formerly known as the Arecibo Ionosphere Observatory, is an observatory in Barrio Esperanza, Arecibo, Puerto Rico owned by the US National Science F ...

and Green Bank Telescope.

Notes

References

{{Sky, 19, 49, 56.81, +, 46, 59, 48.2 1229b Exoplanets discovered in 2016 Exoplanets in the habitable zone Transiting exoplanets Near-Earth-sized exoplanets in the habitable zone Cygnus (constellation) Kepler-1229