Kepler-65

Kepler-65 is a subgiant star slightly more massive than the Sun and has at least four planets.

Kepler-65

Observation data Epoch J2000      Equinox J2000
Constellation	Lyra
Right ascension	19h 14m 45.2916s[1]
Declination	+41° 09′ 04.210″[1]
Apparent magnitude (V)	11.018
Characteristics
Evolutionary stage	Subgiant
Spectral type	F6IV
Astrometry
Proper motion (μ)	RA: 1.256(14) mas/yr[1] Dec.: −14.388(12) mas/yr[1]
Parallax (π)	3.3184 ± 0.0108 mas[1]
Distance	983 ± 3 ly (301.4 ± 1.0 pc)
Details
Mass	1.25 M☉
Radius	1.41 R☉
Temperature	6211 K
Metallicity [Fe/H]	+0.17 dex
Rotation	7.911±0.155 days[2]
Other designations
KOI-85, KIC 5866724, TYC 3125-976-1, GSC 03125-00976, 2MASS J19144528+4109042[3]
Database references
SIMBAD	data
KIC	data

Planetary system

Three transiting planets were announced in 2013. A fourth non-transiting planet was discovered using radial velocity measurements in 2019.^[4] The first three planets orbit very close to their star. Initial follow-up radial velocity measurements provided data too noisy to constrain the mass of planets.^[5] Follow-up transit-timing variation analysis helped to measure the mass of Kepler-65d which revealed that it has significantly lower density than Earth.^[6]

Size comparison of the three planets of Kepler 65 with a known radius (artistic concept) with Earth

The Kepler-65 planetary system^[4]

Companion (in order from star)	Mass	Semimajor axis (AU)	Orbital period (days)	Eccentricity	Inclination	Radius
b	2.4+2.4 −1.6 M🜨	0.035	2.1549209+0.0000086 −0.0000074	0.028+0.031 −0.02	92.2+1.3 −1.4°	1.444+0.037 −0.031 R🜨
c	5.4±1.7 M🜨	0.068	5.859697+0.000093 −0.000099	0.02+0.022 −0.013	92.33+0.29 −0.26°	2.623+0.066 −0.056 R🜨
d	4.14+0.79 −0.80 M🜨	0.084	8.13167+0.00024 −0.00021	0.014+0.016 −0.010	92.35+0.18 −0.16°	1.587+0.040 −0.035 R🜨
e	200+200 −50 M🜨	—	258.8+1.5 −1.3	0.283+0.064 −0.071	127.0+27.0 −25.0°	—

External links

• Kepler-65 System
• Kepler-65, The Open Exoplanet Catalogue

References

1. Vallenari, A.; et al. (Gaia collaboration) (2023). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy and Astrophysics. 674: A1. arXiv:2208.00211. Bibcode:2023A&A...674A...1G. doi:10.1051/0004-6361/202243940. S2CID 244398875. Gaia DR3 record for this source at VizieR.
2. 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.
3. "Kepler-65". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 10 January 2017.
4. Mills, Sean M.; et al. (2019). "Long-period Giant Companions to Three Compact, Multiplanet Systems". The Astronomical Journal. 157 (4). 145. arXiv:1903.07186. Bibcode:2019AJ....157..145M. doi:10.3847/1538-3881/ab0899. S2CID 119197547.
5. Chaplin, W. J.; et al. (2013). "Asteroseismic Determination of Obliquities of the Exoplanet Systems Kepler-50 and Kepler-65". The Astrophysical Journal. 766 (2). 101. arXiv:1302.3728. Bibcode:2013ApJ...766..101C. doi:10.1088/0004-637X/766/2/101.
6. Hadden, Sam; Lithwick, Yoram (2014). "Densities and Eccentricities of 139 Kepler Planets from Transit Time Variations". The Astrophysical Journal. 787 (1). 80. arXiv:1310.7942. Bibcode:2014ApJ...787...80H. doi:10.1088/0004-637X/787/1/80.