# Astronomy:Kepler-35

(Redirected from Astronomy:Kepler-35b)
Short description: Binary star system in the constellation Cygnus
Kepler-35
Observation data
Equinox J2000.0]] (ICRS)
Constellation Cygnus
Right ascension  19h 37m 59.2726s[1]
Declination +46° 41′ 22.952″[1]
Characteristics
Spectral type G / G[2]
Variable type Algol[3]
Astrometry
Proper motion (μ) RA: −2.279±0.058[1] mas/yr
Dec.: −8.262±0.070[1] mas/yr
Parallax (π)0.5215 ± 0.0336[1] mas
Distance6,300 ± 400 ly
(1,900 ± 100 pc)
Orbit[3]
Period (P)20.73 d
Semi-major axis (a)0.176 au
Eccentricity (e)0.16
Inclination (i)89.44°
Details[4]
Kepler-35A
Mass0.8877 M
Luminosity0.94 L
Surface gravity (log g)4.3623 cgs
Temperature5,606 K
Metallicity-0.13
Kepler-35B
Mass0.8094 M
Luminosity0.41 L
Surface gravity (log g)4.5556 cgs
Temperature5,202 K
Metallicity-0.13
Age8-12 Myr
Other designations
KOI-2937, KIC 9837578, 2MASS J19375927+4641231
Database references
KICdata

Kepler-35 is a binary star system in the constellation of Cygnus. These stars, called Kepler-35A and Kepler-35B have masses of 89% and 81% solar masses respectively, and both are assumed to be of spectral class G. They are separated by 0.176 AU, and complete an eccentric orbit around a common center of mass every 20.73 days.[4]

## Description

The Kepler-35 system consists of two stars slightly less massive than the sun in a 21-day orbit aligned edge-on to us so that the stars eclipse each other. The orbit has a semi-major axis 0.2 au and a mild eccentricity of 0.16. of The precise measurements made by the Kepler satellite allow doppler beaming to be detected, as well as brightness variations due to the ellipsoidal shape of the stars and reflections of one star on the other.[4]

The primary star has a mass of 0.9 M and a radius fractionally larger than the sun. With an effective temperature of 5,606 K, its luminosity is 0.94 L. The secondary star has a mass of 0.8 M, a radius of 0.8 R, an effective surface temperature of 5,202 K, and a bolometric luminosity of 0.4 L.[4]

## Planetary system

Kepler-35b is a gas giant that orbits the two stars in the Kepler-35 system. The planet is over an eighth of Jupiter's mass and has a radius of 0.728 Jupiter radii. The planet completes a somewhat eccentric orbit every 131.458 days from a semimajor axis of just over 0.6 AU, only about 3.5 times the semi-major axis between the parent stars. The proximity and eccentricity of the binary star as well as both stars have similar masses results the planet's orbit to significantly deviate from Keplerian orbit.[5] Studies have suggested that this planet must have been formed outside its current orbit and migrated inwards later.[6] The eccentricity of planetary orbit is acquired on the last stage of migration, due to interaction with the residual debris disk.[7]

Numerical simulation of formation of planetary system Kepler-35 has shown the formation of additional rocky planets in the habitable zone is highly likely, and these planetary orbits are stable.[8]

The Kepler-35 planetary system
Companion
(in order from star)
Mass Semimajor axis
(AU)
Orbital period
(days)
b 0.127 MJ 0.60347 131.458 0.042 90.760° 0.728 RJ

## References

1. Brown, A. G. A. (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics 616: A1. doi:10.1051/0004-6361/201833051. Bibcode2018A&A...616A...1G.  Gaia DR2 record for this source at VizieR.
2.
3. Coughlin, J. L.; López-Morales, M.; Harrison, T. E.; Ule, N.; Hoffman, D. I. (2011). "Low-mass Eclipsing Binaries in the Initial Kepler Data Release". The Astronomical Journal 141 (3): 78. doi:10.1088/0004-6256/141/3/78. Bibcode2011AJ....141...78C.
4. Welsh, William F. et al. (2012). "Transiting circumbinary planets Kepler-34 b and Kepler-35 b". Nature 481 (7382): 475–479. doi:10.1038/nature10768. PMID 22237021. Bibcode2012Natur.481..475W.
5. Leung, Gene C. K.; Hoi Lee, Man (2013). "An Analytic Theory for the Orbits of Circumbinary Planets". The Astrophysical Journal 763 (2): 107. doi:10.1088/0004-637X/763/2/107. Bibcode2013ApJ...763..107L.
6. Paardekooper, Sijme-Jan; Leinhardt, Zoë M.; Thébault, Philippe; Baruteau, Clément (2012). "HOW NOT TO BUILD TATOOINE: THE DIFFICULTY OF IN SITU FORMATION OF CIRCUMBINARY PLANETS KEPLER 16b, KEPLER 34b, AND KEPLER 35b". The Astrophysical Journal 754 (1): L16. doi:10.1088/2041-8205/754/1/L16. Bibcode2012ApJ...754L..16P.
7. Pierens, A.; Nelson, R. P. (2013), "Migration and gas accretion scenarios for the Kepler 16, 34 and 35 circumbinary planets", Astronomy & Astrophysics 556: A134, doi:10.1051/0004-6361/201321777, Bibcode2013A&A...556A.134P
8. Macau, E E N.; Domingos, R. C.; Izidoro, A.; Amarante, A.; Winter, O. C.; Barbosa, G. O. (2020), "Earth-size planet formation in the habitable zone of circumbinary stars", Monthly Notices of the Royal Astronomical Society 494: 1045–1057, doi:10.1093/mnras/staa757