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

super-Earth A super-Earth is a type of exoplanet with a mass higher than Earth, but substantially below those of the Solar System's ice giants, Uranus and Neptune, which are 14.5 and 17.1 times Earth's, respectively. The term "super-Earth" refers only to t ...

exoplanet An exoplanet or extrasolar planet is a planet outside the Solar System. The first confirmed detection of an exoplanet was in 1992 around a pulsar, and the first detection around a main-sequence star was in 1995. A different planet, first det ...

, likely

rocky ''Rocky'' is a 1976 American independent film, independent sports drama film directed by John G. Avildsen and written by and starring Sylvester Stallone. It is the first installment in the Rocky (film series), ''Rocky'' franchise and also star ...

, orbiting within the

habitable zone In astronomy and astrobiology, the habitable zone (HZ), or more precisely the circumstellar habitable zone (CHZ), is the range of orbits around a star within which a planetary surface can support liquid water given sufficient atmospheric pressu ...

of the

red dwarf A red dwarf is the smallest kind of star on the main sequence. Red dwarfs are by far the most common type of fusing star in the Milky Way, at least in the neighborhood of the Sun. However, due to their low luminosity, individual red dwarfs are ...

Kepler-1229, located about 870

light year A light-year, alternatively spelled light year (ly or lyr), is a unit of length used to express astronomical distance, astronomical distances and is equal to exactly , which is approximately 9.46 trillion km or 5.88 trillion mi. As defined by t ...

s (267

parsec The parsec (symbol: pc) is a unit of length used to measure the large distances to astronomical objects outside the Solar System, approximately equal to or (AU), i.e. . The parsec unit is obtained by the use of parallax and trigonometry, and ...

s) from Earth in the constellation of Cygnus. It was discovered in 2016 by the ''

Kepler Johannes Kepler (27 December 1571 – 15 November 1630) was a German astronomer, mathematician, astrologer, natural philosopher and writer on music. He is a key figure in the 17th-century Scientific Revolution, best known for his laws of p ...

'' space telescope.1st Alien Earth Still Elusive Despite Huge Exoplanet Haul
, Mike Wall, ''Space.com'' The exoplanet was found by using the

transit method Methods of detecting exoplanets usually rely on indirect strategies – that is, they do not directly image the planet but deduce its existence from another signal. Any planet is an extremely faint light source compared to its parent star. For e ...

, 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

, an exoplanet with a radius and mass bigger than Earth, but smaller than that of the gas giants

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

and

Uranus Uranus is the seventh planet from the Sun. It is a gaseous cyan-coloured ice giant. Most of the planet is made of water, ammonia, and methane in a Supercritical fluid, supercritical phase of matter, which astronomy calls "ice" or Volatile ( ...

. It is 2.7 times the mass of earth. It has an

equilibrium temperature The planetary equilibrium temperature is a theoretical temperature that a planet would be if it were in radiative equilibrium, typically under the assumption that it radiates as a black body being heated only by its parent star. In this model, th ...

of .

Host star

The planet orbits a ( M-type)

star A star is a luminous spheroid of plasma (physics), plasma held together by Self-gravitation, self-gravity. The List of nearest stars and brown dwarfs, nearest star to Earth is the Sun. Many other stars are visible to the naked eye at night sk ...

named Kepler-1229, 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 The Sun is the star at the centre of the Solar System. It is a massive, nearly perfect sphere of hot plasma, heated to incandescence by nuclear fusion reactions in its core, radiating the energy from its surface mainly as visible light a ...

is 4.6 billion years old and has a temperature of 5778 K. The star's

apparent magnitude Apparent magnitude () is a measure of the Irradiance, brightness of a star, astronomical object or other celestial objects like artificial satellites. Its value depends on its intrinsic luminosity, its distance, and any extinction (astronomy), ...

, 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, 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.

Discovery and follow-up studies

In 2013, before the two wheels failed,

NASA The National Aeronautics and Space Administration (NASA ) is an independent agencies of the United States government, independent agency of the federal government of the United States, US federal government responsible for the United States ...

's ''

'' spacecraft was completing observing stars on its

photometer A photometer is an instrument that measures the strength of electromagnetic radiation in the range from ultraviolet to infrared and including the visible spectrum. Most photometers convert light into an electric current using a photoresistor, ...

, the instrument it uses to detect

transit Transit may refer to: Arts and entertainment Film * ''Transit'' (1980 film), a 1980 Israeli film * ''Transit'' (1986 film), a Canadian short film * ''Transit'' (2005 film), a film produced by MTV and Staying-Alive about four people in countrie ...

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 The Kepler Input Catalog (or KIC) is a publicly searchable database of roughly 13.2 million targets used for the Kepler Spectral Classification Program (SCP) and the Kepler space telescope. Overview The Kepler SCP targets were observed by t ...

, 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 Tess or TESS may refer to: Film and theatre * Tess (1979 film), ''Tess'' (1979 film), a 1979 film adaptation of ''Tess of the d'Urbervilles'' * Tess (2016 film), ''Tess'' (2016 film), a South African production Music * Tess (band), a Spanish pop ...

and

CHEOPS Khufu or Cheops (died 2566 BC) was an ancient Egyptian monarch who was the second pharaoh of the Fourth Dynasty, in the first half of the Old Kingdom period (26th century BC). Khufu succeeded his father Sneferu as king. He is generally accep ...

, 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 designed to conduct infrared astronomy. As the largest telescope in space, it is equipped with high-resolution and high-sensitivity instruments, allowing it to view objects too old, Lis ...

and future large ground-based telescopes to analyze atmospheres, determine masses and infer compositions. Additionally the

Square Kilometer Array The Square Kilometre Array (SKA) is an intergovernmental international radio telescope project being built in Australia (low-frequency) and South Africa (mid-frequency). The combining infrastructure, the Square Kilometre Array Observatory (SK ...

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 The Robert C. Byrd Green Bank Telescope (GBT) in Green Bank, West Virginia, US is the world's largest fully steerable radio telescope, surpassing the Effelsberg 100-m Radio Telescope in Germany. The Green Bank site was part of the National Rad ...

Notes

References

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