Kepler-61

Last updated
Kepler-61
Observation data
Epoch J2000       Equinox J2000
Constellation Cygnus
Right ascension 19h 41m 13.0815s [1]
Declination +42° 28 30.984 [1]
Apparent magnitude  (V)15
Characteristics
Evolutionary stage Main sequence
Spectral type K7V [2]
Astrometry
Proper motion (μ)RA: −2.066(50)  mas/yr [1]
Dec.: 10.687(52)  mas/yr [1]
Parallax (π)2.9296 ± 0.0418  mas [1]
Distance 1,110 ± 20  ly
(341 ± 5  pc)
Details
Mass 0.635 ± 0.037 [3]   M
Radius 0.62 ± 0.03 [3]   R
Luminosity 0.08  L
Temperature 4017 +49
150
[2]   K
Metallicity [Fe/H]0.03 ± 0.14 [3]   dex
Rotation 35.078±0.924 days [4]
Age >1 [3]   Gyr
Other designations
KIC   6960913, KOI-1361
Database references
SIMBAD data

Kepler-61 is a K-type main-sequence star approximately 1,100 light years from Earth in the constellation Cygnus. It is located within the field of vision of the Kepler spacecraft, the satellite that NASA's Kepler Mission used to detect planets that may be transiting their stars. On April 24, 2013 it was announced that the star has an extrasolar planet (a super-Earth) orbiting in the inner edge of the habitable zone, named Kepler-61b. [2]

Contents

Nomenclature and history

The Kepler Space Telescope search volume, in the context of the Milky Way Galaxy. LombergA1024.jpg
The Kepler Space Telescope search volume, in the context of the Milky Way Galaxy.

Prior to Kepler observation, Kepler-61 had the 2MASS catalogue number 2MASS J19411308+422831. In the Kepler Input Catalog it has the designation of KIC 6960913, and when it was found to have transiting planet candidates it was given the Kepler object of interest number of KOI-1361.

Planetary candidates were detected around the star by NASA's Kepler Mission, a mission tasked with discovering planets in transit around their stars. The transit method that Kepler uses involves detecting dips in brightness in stars. These dips in brightness can be interpreted as planets whose orbits pass in front of their stars from the perspective of Earth, although other phenomenon can also be responsible which is why the term planetary candidate is used. [5]

Following the acceptance of the discovery paper, the Kepler team provided an additional moniker for the system of "Kepler-61". [6] The discoverers referred to the star as Kepler-61, which is the normal procedure for naming the exoplanets discovered by the spacecraft. [2] Hence, this is the name used by the public to refer to the star and its planet.

Candidate planets that are associated with stars studied by the Kepler Mission are assigned the designations ".01" etc. after the star's name, in the order of discovery. [7] If planet candidates are detected simultaneously, then the ordering follows the order of orbital periods from shortest to longest. [7] Following these rules, there was only one candidate planet were detected, with an orbital period of 59.87756 days.

The designation b, derive from the order of discovery. The designation of b is given to the first planet orbiting a given star, followed by the other lowercase letters of the alphabet. [8] In the case of Kepler-61, there was only one planet detected, so only the letter b is used. The name Kepler-61 derives directly from the fact that the star is the catalogued 61st star discovered by Kepler to have confirmed planets.

Stellar characteristics

Kepler-61 is a K-type main sequence star that is approximately 63% the mass of and 62% the radius of the Sun. It has a temperature of 4017 K and is about 1 billion years old. [3] In comparison, the Sun is about 4.6 billion years old [9] and has a temperature of 5778 K. [10]

The star is a bit more rich in metals then the Sun, with a metallicity ([Fe/H]) of about 0.03, or about 107% of the amount of iron and other heavier metals found in the Sun. [3] The star's luminosity is somewhat normal for a star like Kepler-61, with a luminosity of around 8% of that of the solar luminosity.

The star's apparent magnitude, or how bright it appears from Earth's perspective, is 15. Therefore, it is too dim to be seen with the naked eye.

Planetary system

The Kepler-61 planetary system [2]
Companion
(in order from star)
Mass Semimajor axis
(AU)
Orbital period
(days)
Eccentricity Inclination Radius
b 6.65  M🜨 0.2659.87756<0.25>89.80° 2.15 ± 0.13  R🜨

The only known planet transits the star; this means that the planet's orbit appear to cross in front of their star as viewed from the Earth's perspective. Its inclination relative to Earth's line of sight, or how far above or below the plane of sight they are, vary by less than one degree. This allows direct measurements of the planet's periods and relative diameters (compared to the host star) by monitoring the planet's transit of the star.

Kepler-61b is a super-Earth with a radius 2.15 times that of Earth, and orbits near the inner edge of the habitable zone. It has an eccentric orbit that takes it in and out and thus experiences temperature swings, which may hinder its habitability. Also because of its radius, it may be a mini-Neptune, without a solid surface.

See also

Related Research Articles

<span class="mw-page-title-main">Kepler-22b</span> Super-Earth exoplanet orbiting Kepler-22

Kepler-22b is an exoplanet orbiting within the habitable zone of the Sun-like star Kepler-22. It is located about 640 light-years from Earth in the constellation of Cygnus. It was discovered by NASA's Kepler Space Telescope in December 2011 and was the first known transiting planet to orbit within the habitable zone of a Sun-like star, where liquid water could exist on the planet's surface. Kepler-22 is too dim to be seen with the naked eye.

<span class="mw-page-title-main">Kepler-42</span> Red dwarf star in the constellation Cygnus

Kepler-42, formerly known as KOI-961, is a red dwarf located in the constellation Cygnus and approximately 131 light years from the Sun. It has three known extrasolar planets, all of which are smaller than Earth in radius, and likely also in mass.

Kepler-47 is a binary star system in the constellation Cygnus located about 3,420 light-years away from Earth. The stars have three exoplanets, all of which orbit both stars at the same time, making this a circumbinary system. The first two planets announced are designated Kepler-47b, and Kepler-47c, and the third, later discovery is Kepler-47d. Kepler-47 is the first circumbinary multi-planet system discovered by the Kepler mission. The outermost of the planets is a gas giant orbiting within the habitable zone of the stars. Because most stars are binary, the discovery that multi-planet systems can form in such a system has impacted previous theories of planetary formation.

<span class="mw-page-title-main">Kepler-62</span> K-type star in the constellation Lyra

Kepler-62 is a K-type main sequence star cooler and smaller than the Sun, located roughly 980 light-years from Earth in the constellation Lyra. It resides within the field of vision of the Kepler spacecraft, the satellite that NASA's Kepler Mission used to detect planets that may be transiting their stars. On April 18, 2013, it was announced that the star has five planets, two of which, Kepler-62e and Kepler-62f are within the star's habitable zone. The outermost, Kepler-62f, is likely a rocky planet.

<span class="mw-page-title-main">Kepler-62e</span> Habitable-zone super-Earth planet orbiting Kepler-62

Kepler-62e is a super-Earth exoplanet discovered orbiting within the habitable zone of Kepler-62, the second outermost of five such planets discovered by NASA's Kepler spacecraft. Kepler-62e is located about 990 light-years from Earth in the constellation of Lyra. The exoplanet was found using the transit method, in which the dimming effect that a planet causes as it crosses in front of its star is measured. Kepler-62e may be a terrestrial or ocean-covered planet; it lies in the inner part of its host star's habitable zone.

<span class="mw-page-title-main">Kepler-69</span> Star in the constellation Cygnus

Kepler-69 is a G-type main-sequence star similar to the Sun in the constellation Cygnus, located about 2,390 ly (730 pc) from Earth. On April 18, 2013 it was announced that the star has two planets. Although initial estimates indicated that the terrestrial planet Kepler-69c might be within the star's habitable zone, further analysis showed that the planet very likely is interior to the habitable zone and is far more analogous to Venus than to Earth and thus completely inhospitable.

Kepler-62c is an approximately Mars-sized exoplanet discovered in orbit around the star Kepler-62, the second innermost of five discovered by NASA's Kepler spacecraft around Kepler-62. At the time of discovery it was the second-smallest exoplanet discovered and confirmed by the Kepler spacecraft, after Kepler-37b. 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. Its stellar flux is 25 ± 3 times Earth's. It is similar to Mercury.

Kepler-62d 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. 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 510 K, too hot to sustain life on its surface.

Kepler-61b is a super-Earth exoplanet orbiting within parts of the habitable zone of the K-type main-sequence star Kepler-61. It is located about 1,100 light-years from Earth in the constellation of Cygnus. It was discovered in 2013 using the transit method, in which the dimming effect that a planet causes as it crosses in front of its star is measured, by NASA's Kepler spacecraft.

<span class="mw-page-title-main">Kepler-138</span> Red dwarf in the constellation Lyra

Kepler-138, also known as KOI-314, is a red dwarf located in the constellation Lyra, 219 light years from Earth. It is located within the field of vision of the Kepler spacecraft, the satellite that NASA's Kepler Mission used to detect planets transiting their stars.

<span class="mw-page-title-main">Kepler-442b</span> Super-Earth orbiting Kepler-442

Kepler-442b is a confirmed near-Earth-sized exoplanet, likely rocky, orbiting within the habitable zone of the K-type main-sequence star Kepler-442, about 1,206 light-years (370 pc) from Earth in the constellation of Lyra.

<span class="mw-page-title-main">Kepler-452</span> G-type main-sequence star in the constellation Cygnus

Kepler-452 is a G-type main-sequence star located about 1,810 light-years away from Earth in the Cygnus constellation. Although similar in temperature to the Sun, it is 20% brighter, 3.7% more massive and 11% larger. Alongside this, the star is approximately six billion years old and possesses a high metallicity.

Kepler-419c is a super-Jupiter exoplanet orbiting within the habitable zone of the star Kepler-419, the outermost of two such planets discovered by NASA's Kepler spacecraft. It is located about 3,400 light-years from Earth in the constellation Cygnus. The exoplanet was found by using the transit timing variation method, in which the variations of transit data from an exoplanet are studied to reveal a more distant companion.

Kepler-1229 is a red dwarf star located about 870 light-years (270 pc) 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.

K2-72 is a cool red dwarf star of spectral class M2.7V located about 217 light-years away from the Earth in the constellation of Aquarius. It is known to host four planets, all similar in size to Earth, with one of them residing within the habitable zone.

Kepler-442 is a K-type main-sequence star approximately 1,196 light years from Earth in the constellation Lyra. It is located within the field of vision of the Kepler spacecraft, the satellite that NASA's Kepler Mission used to detect planets that may be transiting their stars. On January 6, 2015, along with the notable stars of Kepler-438 and Kepler-440, it was announced that the star has an extrasolar planet orbiting within the habitable zone, named Kepler-442b.

Kepler-419 is an F-type main-sequence star located about 3,280 light years from Earth in the constellation Cygnus. It is located within the field of vision of the Kepler spacecraft, the satellite that NASA's Kepler Mission used to detect planets that may be transiting their stars. In 2012, a potential planetary companion in a very eccentric orbit was detected around this star, but its planetary nature was not confirmed until 12 June 2014, when it was named Kepler-419b. A second planet was announced orbiting further out from the star in the same paper, named Kepler-419c.

Kepler-432 is a binary star system with at least two planets in orbit around the primary companion, located about 2,780 light-years away from Earth.

<span class="mw-page-title-main">K2-33</span> Star in the constellation Scorpius

K2-33 is an extremely young pre-main-sequence star located about 453 light-years (139 pc) away from the Earth in the constellation of Scorpius. It is known to host one planet, a super-Neptune, named K2-33b. It is also notable for its young age.

Kepler-1708b is a Jupiter-sized exoplanet orbiting the Sun-like star Kepler-1708, located in the constellation of Cygnus approximately 5,600 light years away from Earth. It was first detected in 2011 by NASA's Kepler mission using the transit method, but was not identified as a candidate planet until 2019. In 2021, a candidate Neptune-sized exomoon in orbit around Kepler-1708b was found by astronomer David Kipping and colleagues in an analysis using Kepler transit data. However, subsequent research has raised discrepancies about the possible existence of an exomoon, similar to that of Kepler-1625b.

References

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  2. 1 2 3 4 5 Exoplanet Characterization by Proxy: a Transiting 2.15 R_Earth Planet Near the Habitable Zone of the Late K dwarf Kepler-61 Sarah Ballard, David Charbonneau, Francois Fressin, Guillermo Torres, Jonathan Irwin, Jean-Michel Desert, Elisabeth Newton, Andrew W. Mann, David R. Ciardi, Justin R. Crepp, Christopher E. Henze, Stephen T. Bryson, Steven B. Howell, Elliott P. Horch, Mark E. Everett, Avi Shporer et al. April 26, 2013
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  5. Morton, Timothy; Johnson, John (23 August 2011). "On the Low False Positive Probabilities of Kepler Planet Candidates". The Astrophysical Journal. 738 (2): 170. arXiv: 1101.5630 . Bibcode:2011ApJ...738..170M. doi:10.1088/0004-637X/738/2/170. S2CID   35223956.
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