Observation data Epoch J2000 Equinox J2000 | |
---|---|
Constellation | Cygnus |
Right ascension | 19h 44m 27.0201s [1] |
Declination | 39° 58′ 43.594″ [1] |
Apparent magnitude (V) | 14.804 |
Characteristics | |
Spectral type | M0V [2] |
Variable type | planetary transit |
Astrometry | |
Proper motion (μ) | RA: −1.373(20) mas/yr [1] Dec.: −7.207(24) mas/yr [1] |
Parallax (π) | 2.6675 ± 0.0183 mas [1] |
Distance | 1,223 ± 8 ly (375 ± 3 pc) |
Details | |
Mass | 0.730 M☉ |
Radius | 0.678 R☉ |
Luminosity | 0.170 L☉ |
Temperature | 4540 K |
Metallicity [Fe/H] | −0.56 [3] dex |
Rotation | 25.567±0.252 days [4] |
Other designations | |
Database references | |
SIMBAD | data |
KIC | data |
Kepler-80, also known as KOI-500, is a red dwarf star of the spectral type M0V. [2] This stellar classification places Kepler-80 among the very common, cool, class M stars that are still within their main evolutionary stage, known as the main sequence. Kepler-80, like other red dwarf stars, is smaller than the Sun, and it has both radius, mass, temperatures, and luminosity lower than that of our own star. [5] Kepler-80 is found approximately 1,223 light years from the Solar System, in the stellar constellation Cygnus, also known as the Swan.
The Kepler-80 system has 6 known exoplanets. [6] [7] The discovery of the five inner planets was announced in October 2012, marking Kepler-80 as the first star identified with five orbiting planets. [8] [5] In 2017, an additional planet, Kepler-80g, was discovered by use of artificial intelligence and deep learning to analyse data from the Kepler space telescope. [7] The method used to discover Kepler-80g had been developed by Google, and during the same study another planet was found, Kepler-90i, which brought the total number of known planets in Kepler-90 up to 8 planets. [9]
The exoplanets around Kepler-80 were discovered and observed using the Kepler Space Telescope. This telescope uses the so called transit method , where the planets move in between the star and the Earth and thereby dim the light of the star as seen from the Earth. By using photometry the transit of a planet in front of its star can be seen as a dip in the light curve of the star. After the initial discovery the five innermost planets have all been confirmed through additional investigations. Kepler-80b and Kepler-80c were both confirmed in 2013 based on their transit-timing variation (TTV). [10] Kepler-80d and Kepler-80e were validated in 2014 based on statistical analysis of the Kepler data. [11] [12] Finally the innermost planet, Kepler-80f was confirmed in 2016. [12]
All six known planets in the Kepler-80 system orbit very close to the star, and their distances to the star (the semi-major axes are all smaller than 0.2 AU). For comparison the planet in the Solar System closest to the star, Mercury, has a semi major axis of 0.389 AU, and so the entire known system of Kepler-80 can lie within the orbit of Mercury. [13] This makes Kepler-80 a very compact system and it is one of many STIP's (Systems with Tightly-packed Inner Planets) that have been discovered by the Kepler telescope. [8]
In 2014, the dynamical simulation shown what the Kepler-80 planetary system have likely to undergone a substantial inward migration in the past, producing an observed pattern of lower-mass planets on tightest orbits. [14]
Companion (in order from star) | Mass | Semimajor axis (AU) | Orbital period (days) | Eccentricity | Inclination | Radius |
---|---|---|---|---|---|---|
f | — | 0.0175 ± 0.0002 | 0.98678730 ± 0.00000006 | ~0 | 86.50 +2.36 −2.59 ° | 1.031+0.033 −0.027 [18] R🜨 |
d | 4.1 ± 0.4 [19] M🜨 | 0.0372 ± 0.0005 [18] | 3.07221 ± 0.00003 | 0.005+0.004 −0.003 [19] | 88.35 +1.12 −1.51 [18] ° | 1.309+0.036 −0.032 [18] R🜨 |
e | 2.2 ± 0.4 [19] M🜨 | 0.0491 ± 0.0007 [18] | 4.6453 +0.00010 −0.00009 [19] | 0.008 ± 0.004 [19] | 88.79 +0.84 −1.07 [18] ° | 1.330+0.039 −0.038 [18] R🜨 |
b | 2.4 ± 0.6 [19] M🜨 | 0.0658 ± 0.0009 [18] | 7.05325 ± 0.00009 [19] | 0.006 +0.005 −0.004 [19] | 89.34 +0.46 −0.62 [18] ° | 2.367+0.055 −0.052 [18] R🜨 |
c | 3.4+0.9 −0.7 [19] M🜨 | 0.0792 ± 0.0011 [18] | 9.5232 ± 0.0002 [19] | 0.010 +0.006 −0.005 [19] | 89.33 +0.47 −0.57 [18] ° | 2.507+0.061 −0.058 [18] R🜨 |
g | 1.0 ± 0.3 [19] M🜨 | 0.142 +0.037 −0.051 [18] | 14.6471 +0.0007 −0.0012 [19] | 0.02 +0.03 −0.02 [19] | 89.35 +0.47 −0.98 [18] ° | 1.05+0.22 −0.24 [18] R🜨 |
The system Kepler-80 has orbits locked in a trio of three-body mean-motion orbital resonances; between Kepler-80 d, e, and b; between Kepler-80 e, b, and c; and between Kepler-80 b, c, and g. Interestingly, no two-body resonances have been found to exist in this system. [19]
While Kepler-80 d, e, b, c and g's periods are in a ~ 1.000: 1.512: 2.296: 3.100: 4.767 ratio, in a frame of reference that rotates with the conjunctions this reduces to a ratio of 4:6:9:12:18. Conjunctions of d and e, e and b, b and c, and c and g occur at relative intervals of 2:3:6:6 in a pattern that repeats about every 191 days. Modeling indicates the resonant system is stable to perturbations. Triple conjunctions do not occur. [7] [15]
The Hungarian Automated Telescope Network (HATNet) project is a network of six small fully automated "HAT" telescopes. The scientific goal of the project is to detect and characterize extrasolar planets using the transit method. This network is used also to find and follow bright variable stars. The network is maintained by the Center for Astrophysics | Harvard & Smithsonian.
Kepler-32 is an M-type main sequence star located about 1053 light years from Earth, in the constellation of Cygnus. Discovered in January 2012 by the Kepler spacecraft, it shows a 0.58 ± 0.05 solar mass (M☉), a 0.53 ± 0.04 solar radius (R☉), and temperature of 3900.0 K, making it half the mass and radius of the Sun, two-thirds its temperature and 5% its luminosity.
Kepler-65 is a subgiant star slightly more massive than the Sun and has at least four planets.
Kepler-23 is a G-type main-sequence star about 2,860 light-years away in the northern constellation of Cygnus, the swan. With an apparent visual magnitude of 13.5, it is too faint to be seen with the naked eye. This star is similar in mass and temperature to the Sun, but is larger and more luminous. Kepler-23 is orbited by three known exoplanets.
Kepler-26 is a star in the northern constellation of Lyra. It is located at the celestial coordinates: Right Ascension 18h 59m 45.8408s Declination +46° 33′ 59.438″. With an apparent visual magnitude of 15.5, this star is too faint to be seen with the naked eye.
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.
Kepler-30 is a star in the northern constellation of Lyra. It is located at the celestial coordinates: Right Ascension 19h 01m 08.0746s Declination +38° 56′ 50.218″. With an apparent visual magnitude of 15.5, this star is too faint to be seen with the naked eye. Kepler-30 is exhibiting a strong starspot activity.
Kepler-27 is a star in the northern constellation of Cygnus, the swan. It is located at the celestial coordinates: Right Ascension 19h 28m 56.81962s, Declination +41° 05′ 09.1405″. With an apparent visual magnitude of 15.855, this star is too faint to be seen with the naked eye.
Kepler-296f is a confirmed super-Earth exoplanet orbiting within the habitable zone of Kepler-296. 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 discovery of the exoplanet on 26 February 2014.
Kepler-24d is a transiting exoplanet orbiting the star Kepler-24, located in the constellation Lyra. It was discovered by the Kepler telescope in February 2014. It orbits its parent star at only 0.051 astronomical units away, and at its distance it completes an orbit once every 4.244384 days.
Kepler-24e is a transiting exoplanet orbiting the star Kepler-24, located in the constellation Lyra. It was discovered by the Kepler telescope in February 2014. It orbits its parent star at only 0.138 astronomical units away, and at its distance it completes an orbit once every 19 days.
Kepler-26e is an exoplanet orbiting the star Kepler-26, located in the constellation Lyra. It was discovered by the Kepler telescope in February 2014. It orbits its parent star at only 0.220 astronomical units and completes an orbit once every 46.8 days. It is located within the star's habitable zone.
HD 179070, also known as Kepler-21, is a star with a closely orbiting exoplanet in the northern constellation of Lyra. At an apparent visual magnitude of 8.25 this was the brightest star observed by the Kepler spacecraft to host a validated planet until the discovery of an exoplanet orbiting HD 212657 in 2018. This system is located at a distance of 354 light-years from the Sun based on parallax measurements, but is drifting closer with a radial velocity of −18.2 km/s.
Kepler-160 is a main-sequence star approximately the width of our Galactic arm away in the constellation Lyra, first studied in detail by the Kepler Mission, a NASA-led operation tasked with discovering terrestrial planets. The star, which is very similar to the Sun in mass and radius, has three confirmed planets and one unconfirmed planet orbiting it.
Kepler-167 is a K-type main-sequence star located about 1,119 light-years (343 pc) away from the Solar System in the constellation of Cygnus. The star has about 78% the mass and 75% the radius of the Sun, and a temperature of 4,884 K. It hosts a system of four known exoplanets. There is also a companion red dwarf star at a separation of about 700 AU, with an estimated orbital period of over 15,000 years.