K2-24

Last updated
K2-24
Observation data
Epoch J2000       Equinox J2000
Constellation Scorpius [1]
Right ascension 16h 10m 17.6977s [2]
Declination −24° 59′ 25.261″ [2]
Apparent magnitude  (V)11.068±0.110 [3]
Characteristics
Spectral type G3V [4]
Apparent magnitude  (J)9.635±0.024 [5]
Apparent magnitude  (H)9.294±0.022 [5]
Apparent magnitude  (K)9.180±0.021 [5]
Variable type Planetary transit [4]
Astrometry
Radial velocity (Rv)1.18(32) [2]  km/s
Proper motion (μ)RA: −59.891(21) [2]   mas/yr
Dec.: −58.702(14) [2]   mas/yr
Parallax (π)5.8273 ± 0.0169  mas [2]
Distance 560 ± 2  ly
(171.6 ± 0.5  pc)
Details [6]
Mass 1.07±0.06  M☉
Radius 1.16±0.04  R☉
Surface gravity (log g)4.29±0.05  cgs
Temperature 5625±60  K
Metallicity [Fe/H]0.34±0.04  dex
Other designations
Gaia DR2  6049750234317822208, EPIC  203771098, TYC  6784-837-1, 2MASS J16101770-2459251 [7]
Database references
SIMBAD data

K2-24 (also known as EPIC 203771098) is a metal-rich G3-type main sequence star larger and more massive than the Sun, located 560 light-years (172 parsecs ) away in the constellation Scorpius. Two confirmed transiting exoplanets are known to orbit this star. [4] An attempt to detect stellar companions using adaptive optics imaging at the Keck telescope was negative [4] however later observations using lucky imaging at the Danish 1.54 m telescope at La Silla Observatory detected a possible companion at 3.8 arcseconds distance from K2-24. This candidate companion being over 8 magnitudes fainter than K2-24 and with a color temperature of 5400  Kelvin , is inconsistent with a bound main sequence companion. [8]

Contents

Planetary system

Discovery

Erik A. Petigura and team analyzed data obtained from the Kepler space telescope during its observation of the K2 Campaign 2 field. They reported the discovery and confirmation of both planets b and c. [4] The Planetary signals were independently detected by Andrew Vanderburg and collaborators. [9]

Characteristics

The two known planets in this system have radii equal to 5.4 and 7.5 times that of the Earth. This places both planets radii between that of Uranus and Saturn, a range not present within the Solar System. With orbital periods of 20.9 days and 42.4 days, the planets are within 1% of the 2:1 mean-motion resonance. The low observed eccentricities and near orbital resonance provide evidence regarding the formation and evolution of the system, suggesting that they could possibly have resulted from gravitational interactions with a protoplanetary disk. K2-24c at 15.4 earth masses is significantly lighter than K2-24b's 19 Earth masses despite being a larger planet. It is estimated that K2-24b's atmosphere makes up 26% of its mass while K2-24c's atmosphere makes up 52%. The current model of core-nucleated accretion predicts that runaway accretion should occur when a planet reaches approximately 50% atmosphere by mass, this makes K2-24c a potential challenge to the model. [6]

A transit observation of K2-24b with the Hubble Space Telescope's Wide Field Camera 3 suggested the presence of ammonia, in a high abundance, but did not find evidence for water. [10]

The K2-24 planetary system [6] [4]
Companion
(in order from star)		 Mass Semimajor axis
(AU)		 Orbital period
(days)		 Eccentricity Inclination Radius
K2-24b 19.0+2.2
−2.1  M🜨 		0.154±0.00220.88977+0.00034
−0.00035		0.06±0.0189.25+0.49
−0.61 ° 		5.4±0.2  R🜨
K2-24c 15.4+1.9
−1.8  M🜨 		0.247±0.00442.3391±0.0012<0.05 [11] 89.76+0.18
−0.21 ° 		7.5±0.3  R🜨
.03(unconfirmed)—————7.5±0.61  R🜨
The possible make up of K2-24 b and c, Consisting of a Hydrogen/Helium Atmosphere (Purple) and a rocky core (Brown). Planete geante a noyau massif.png
The possible make up of K2-24 b and c, Consisting of a Hydrogen/Helium Atmosphere (Purple) and a rocky core (Brown).

Related Research Articles

HD 114386 is a star with a pair of orbiting exoplanets in the southern constellation of Centaurus. It has an apparent visual magnitude of 8.73, which means it cannot be viewed with the naked eye but can be seen with a telescope or good binoculars. Based on parallax measurements, the system is located at a distance of 91 light years from the Sun. It is receding with a radial velocity of 33.4 km/s. The star shows a high proper motion, traversing the celestial sphere at an angular rate of 0.318 arcsec yr−1.

<span class="mw-page-title-main">WASP-4</span> G-type main sequence star in the constellation Phoenix

WASP-4 is a G-type main-sequence star approximately 891 light-years away in the constellation of Phoenix. Despite its advanced age, the star is rotating rapidly, being spun up by the tides raised by a giant planet on a close orbit.

HAT-P-4 is a wide binary star consisting of a pair of G-type main-sequence stars in the constellation of Boötes. It is also designated BD+36°2593.

WASP-24 is an F-type star with the Hot Jupiter planet WASP-24b in orbit. WASP-24 is slightly larger and more massive than the Sun, it is also has a similar Metallicity and is hotter than the Sun. WASP-24 was first observed by the SuperWASP planet-searching organization, which flagged it as a potential host to a planet before following up with radial velocity and spectral measurements. Analysis of these confirmed the planetary nature of WASP-24b, which was later released to the public on the SuperWASP website.

HAT-P-24 is an F8 dwarf star about 413 parsecs away. A planet was discovered with the transit method by the HATNet Project in 2010. HAT-P-24b, is a typical hot Jupiter orbiting in only 3 days.

<span class="mw-page-title-main">Kepler-25</span> Yellow-white hued star in the constellation Lyra

Kepler-25 is a star in the northern constellation of Lyra. It is slightly larger and more massive than the Sun, with a luminosity 21⁄2 times that of the Sun. With an apparent visual magnitude of 10.6, this star is too faint to be seen with the naked eye.

K2-3, also known as EPIC 201367065, is a red dwarf star with three known planets. It is on the borderline of being a late orange dwarf/K-type star, but because of its temperature, it is classified as a red dwarf.

K2-24b also known as EPIC 203771098 b is an exoplanet orbiting the Sun-like star K2-24 every 21 days. It has about the same density as Saturn, at 0.7103 g/cm3, which indicates that the planet is clearly a gas giant.

K2-24c also known as EPIC 203771098 c is an exoplanet orbiting the Sun-like star K2-24 every 42 days. It has a density far lower than that of Saturn, which indicates that the planet is clearly a gas giant.

HIP 41378 is a star located 346 light-years away in the constellation of Cancer. The star has an apparent magnitude of 8.92. This F-type main sequence dwarf has a mass of 1.15 M☉ and a radius of 1.25 R☉. It has a surface temperature of about 6,251 K.

GJ 9827 is a star in the constellation of Pisces. It is a K-type main-sequence star with an apparent magnitude of 10.250. It is 97 light-years away, based on parallax.

<span class="mw-page-title-main">K2-138</span> Star in the constellation Aquarius

K2-138, also designated EPIC 245950175 or EE-1, is a large early K-type main sequence star with a system of at least 6 planets discovered by citizen scientists. Four were found in the first two days of the Exoplanet Explorers project on Zooniverse in early April 2017, while two more were revealed in further analysis. The system is about 660 light-years away in the constellation Aquarius, within K2 Campaign 12.

K2-19 is an early K-type or late G-type main sequence star that is magnetically active, and has a light curve that exhibits variations in brightness of ~1%. It is located approximately 976 light-years away in the constellation Virgo. Three confirmed transiting exoplanets are known to orbit this star.

K2-58 is G-type main-sequence star in the constellation of Aquarius, approximately 596 light-years from Solar System. The star is metal-rich, having 155% of Solar abundance of elements heavier than helium. The star is located in the region allowing to see Venus transiting the Sun for hypothetical observer located in K2-58 system.

K2-28 is a metal rich M4-type main sequence star. One confirmed transiting exoplanet is known to orbit this star. There is another star 5.2 arcseconds to the north–east of K2-28 however this star has a different proper motion and is therefore physically unrelated and probably a background star.

<span class="mw-page-title-main">K2-18</span> Red dwarf star in the constellation Leo

K2-18, also known as EPIC 201912552, is a red dwarf star with two planetary companions located 124 light-years from Earth, in the constellation of Leo.

K2-32 is a G9-type main sequence star slightly smaller and less massive than the sun. Four confirmed transiting exoplanets are known to orbit this star. A study of atmospheric escape from the planet K2-32b caused by high-energy stellar irradiation indicates that the star has always been a very slow rotator.

Kepler-411 is a binary star system. Its primary star Kepler-411A is a K-type main-sequence star, orbited by the red dwarf star Kepler-411B on a wide orbit, discovered in 2012.

<span class="mw-page-title-main">K2-25</span>

K2-25 is a young red dwarf star located in the Hyades cluster. There is a single known Neptune-sized planet in a 3.5 day orbit.

References

  1. ↑ Roman, Nancy G. (1987). "Identification of a Constellation From a Position". Publications of the Astronomical Society of the Pacific. 99 (617): 695–699. Bibcode: 1987PASP...99..695R . doi: 10.1086/132034 . Vizier query form
  2. 1 2 3 4 5 6 Brown, A. G. A.; et al. (Gaia collaboration) (2021). "Gaia Early Data Release 3: Summary of the contents and survey properties". Astronomy & Astrophysics . 649: A1. arXiv: 2012.01533 . Bibcode:2021A&A...649A...1G. doi: 10.1051/0004-6361/202039657 . S2CID   227254300. (Erratum:  doi:10.1051/0004-6361/202039657e). Gaia EDR3 record for this source at VizieR.
  3. ↑ Henden, A. A.; et al. (2016). "VizieR Online Data Catalog: AAVSO Photometric All Sky Survey (APASS) DR9 (Henden+, 2016)". VizieR On-line Data Catalog: II/336. Originally Published in: 2015AAS...22533616H. 2336. Bibcode:2016yCat.2336....0H. Vizier catalog entry
  4. 1 2 3 4 5 6 Petigura, Erik A.; et al. (2016). "Two Transiting Low Density Sub-Saturns from K2". The Astrophysical Journal. 818 (1) 36. arXiv: 1511.04497 . Bibcode: 2016ApJ...818...36P . doi: 10.3847/0004-637X/818/1/36 .
  5. 1 2 3 Skrutskie, Michael F.; et al. (1 February 2006). "The Two Micron All Sky Survey (2MASS)". The Astronomical Journal. 131 (2): 1163–1183. Bibcode: 2006AJ....131.1163S . doi: 10.1086/498708 . Vizier catalog entry
  6. 1 2 3 Petigura, Erik A.; et al. (2018). "Dynamics and Formation of the Near-resonant K2-24 System: Insights from Transit-timing Variations and Radial Velocities". The Astronomical Journal. 156 (3) 89. arXiv: 1806.08959 . Bibcode: 2018AJ....156...89P . doi: 10.3847/1538-3881/aaceac .
  7. ↑ "K2-24". SIMBAD . Centre de données astronomiques de Strasbourg . Retrieved 2019-09-27.
  8. ↑ Evans, D. F.; et al. (2018). "High-resolution Imaging of Transiting Extrasolar Planetary systems (HITEP). II. Lucky Imaging results from 2015 and 2016". Astronomy and Astrophysics. 610 A20. arXiv: 1709.07476 . Bibcode: 2018A&A...610A..20E . doi: 10.1051/0004-6361/201731855 .
  9. ↑ Vanderburg, Andrew; et al. (2016). "Planetary Candidates from the First Year of the K2 Mission". The Astrophysical Journal Supplement Series. 222 (1) 14. arXiv: 1511.07820 . Bibcode: 2016ApJS..222...14V . doi: 10.3847/0067-0049/222/1/14 .
  10. ↑ Edwards, Billy; et al. (2023-11-01). "Exploring the Ability of Hubble Space Telescope WFC3 G141 to Uncover Trends in Populations of Exoplanet Atmospheres through a Homogeneous Transmission Survey of 70 Gaseous Planets". The Astrophysical Journal Supplement Series. 269 (1) 31. Appendix B.9. arXiv: 2211.00649 . Bibcode: 2023ApJS..269...31E . doi: 10.3847/1538-4365/ac9f1a .
  11. ↑ Antoniadou, Kyriaki I.; Libert, Anne-Sophie (23 June 2020). "Exploiting periodic orbits as dynamical clues for Kepler and K2 systems". Astronomy & Astrophysics. 640 A55. arXiv: 2006.12895 . Bibcode: 2020A&A...640A..55A . doi: 10.1051/0004-6361/202037779 . S2CID   219980541.
This page is based on this Wikipedia article
Text is available under the CC BY-SA 4.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.