Kepler-419

Kepler-419 is an F-type main-sequence star located about 3,400 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,[4] 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.[3]

Kepler-419
Observation data
Epoch J2000      Equinox J2000
Constellation Cygnus
Right ascension 19h 41m 40.2991s[1]
Declination +51° 11′ 05.1660″[1]
Apparent magnitude (V) 13.036±0.006[2]
Characteristics
Spectral type F8V[3]
Apparent magnitude (B) 13.498±0.011[2]
Astrometry
Proper motion (μ) RA: −0.072±0.040[1] mas/yr
Dec.: −1.271±0.038[1] mas/yr
Parallax (π)0.9603 ± 0.0241[1] mas
Distance3,400 ± 90 ly
(1,040 ± 30 pc)
Details
Mass1.40+0.06
−0.08[3] M☉
Radius1.57+0.20
−0.18[3] R☉
Luminosity2.7+1.6
−0.8[4] L☉
Surface gravity (log g)4.19±0.09[3] cgs
Temperature6421+76
−80[3] K
Metallicity [Fe/H]0.16+0.08
−0.04[3] dex
Rotation4.492±0.012 days[5]
Rotational velocity (v sin i)14.41±1.3[3] km/s
Age2.8+1.3
−1.2[4] Gyr
Other designations
KOI-1474, KIC 12365184, 2MASS J19414029+5111051[6]
Database references
SIMBADdata
Extrasolar Planets
Encyclopaedia		data

Nomenclature and history

Prior to Kepler observation, Kepler-419 had the 2MASS catalogue number 2MASS J19414029+5111051. In the Kepler Input Catalog it has the designation of KIC 12365184, and when it was found to have transiting planet candidates it was given the Kepler object of interest number of KOI-1474.

The star's planets were discovered 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 move in front of their stars from the perspective of Earth. The name Kepler-419 derives directly from the fact that the star is the catalogued 419th star discovered by Kepler to have confirmed planets.

The designation b and c, derive from the order of discovery. The designation of b is given to the first planet orbiting a given star, and c to the furthest.[7] In the case of Kepler-419, there were two planets detected, so the letters b and c are used.

Stellar characteristics

Kepler-419 is an F-type star that is approximately 139% the mass of and 175% the radius of the Sun. It has a surface temperature of 6430 K and is 2.8 billion years old.[3] In comparison, the Sun is about 4.6 billion years old[8] and has a surface temperature of 5778 K.[9]

The star's apparent magnitude, or how bright it appears from Earth's perspective, is 14. Therefore, it is too dim to be seen with the naked eye.

Planetary system
The Kepler-419 planetary system[10]
Companion
(in order from star)		 Mass Semimajor axis
(AU)		 Orbital period
(days)		 Eccentricity Inclination Radius
b 2.77±0.19 MJ 0.3745±0.0046 69.7960±0.0042 0.817±0.016 87.04±0.72° 1.120±0.084 RJ
c 7.65±0.27 MJ 1.697±0.020 673.35±0.84 0.1793±0.0017 87.0±2.0° —

Only the first planet is known transit 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 it is, 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.

The innermost planet orbits the star every 69 days at a distance nearly the same as the Mercury–Sun distance, which Kepler-419b orbits at 0.37 AU. It has a very eccentric orbit, and as such experiences large temperature swings as its eccentricity is 0.83. The eccentric orbit could not have been caused by the star itself, there must have been a more distant companion. In 2014 the discovery of a 7.3 MJ planet orbiting at 1.68 AU was announced, through the transit-timing variations method.[3]

Kepler-419c is notable because it orbits within its star's habitable zone, and, even though it has a mass 7 times that of Jupiter, it is listed as a good candidate for potentially harboring a habitable exomoon.[11] Because of this, some astronomers have begun taking interest in Kepler-419c to search for these potentially habitable exomoons. As of 2021, no exomoons have been detected in orbit around the planet.

See also

References
  1. Brown, A. G. A.; et al. (Gaia collaboration) (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics. 616. A1. arXiv:1804.09365. Bibcode:2018A&A...616A...1G. doi:10.1051/0004-6361/201833051. Gaia DR2 record for this source at VizieR.
  2. 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
  3. Dawson, Rebekah I.; et al. (2014). "Large eccentricity, low mutual inclination: The three-dimensional architecture of a hierarchical system of giant planets". The Astrophysical Journal. 791 (2). 89. arXiv:1405.5229. Bibcode:2014ApJ...791...89D. doi:10.1088/0004-637X/791/2/89.
  4. Dawson, Rebekah I.; et al. (2012). "The Photoeccentric Effect and Proto-hot Jupiters. II. KOI-1474.01, a Candidate Eccentric Planet Perturbed by an Unseen Companion". The Astrophysical Journal. 761 (2). 163. arXiv:1206.5579. Bibcode:2012ApJ...761..163D. doi:10.1088/0004-637X/761/2/163.
  5. McQuillan, A.; Mazeh, T.; Aigrain, S. (2013). "Stellar Rotation Periods of The Kepler objects of Interest: A Dearth of Close-In Planets Around Fast Rotators". The Astrophysical Journal Letters. 775 (1). L11. arXiv:1308.1845. Bibcode:2013ApJ...775L..11M. doi:10.1088/2041-8205/775/1/L11.
  6. "Kepler-419". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2019-01-24.
  7. Hessman, F. V.; Dhillon, V. S.; Winget, D. E.; Schreiber, M. R.; Horne, K.; Marsh, T. R.; Guenther, E.; Schwope, A.; Heber, U. (2010). "On the naming convention used for multiple star systems and extrasolar planets". arXiv:1012.0707 [astro-ph.SR].
  8. Fraser Cain (16 September 2008). "How Old is the Sun?". Universe Today. Retrieved 19 February 2011.
  9. Fraser Cain (15 September 2008). "Temperature of the Sun". Universe Today. Retrieved 19 February 2011.
  10. Almenara, J. M.; et al. (2018). "SOPHIE velocimetry of Kepler transit candidates. XVIII. Radial velocity confirmation, absolute masses and radii, and origin of the Kepler-419 multiplanetary system". Astronomy and Astrophysics. 615. A90. arXiv:1804.01869. Bibcode:2018A&A...615A..90A. doi:10.1051/0004-6361/201732500.
  11. http://www.hpcf.upr.edu/~abel/phl/hec_plots/hec_orbit/hec_orbit_Kepler-419_c.png

This article is issued from Wikipedia. The text is licensed under Creative Commons - Attribution - Sharealike. Additional terms may apply for the media files.