Kepler-45

Kepler-45, formerly known as KOI-254, is a star in the northern constellation of Cygnus. It is located at the celestial coordinates: right ascension 19^h 31^m 29.495^s, declination +41° 03′ 51.37″.^[6] With an apparent visual magnitude of 16.88,^[4] this star is too faint to be seen with the naked eye.

Kepler-45

Observation data Epoch J2000      Equinox J2000
Constellation	Cygnus[1]
Right ascension	19h 31m 29.4966s[2]
Declination	+41° 03′ 51.356″[2]
Apparent magnitude (V)	16.88[3]
Characteristics
Spectral type	M1 V[4]
Astrometry
Proper motion (μ)	RA: 4.646(36) mas/yr[2] Dec.: −21.589(36) mas/yr[2]
Parallax (π)	2.5984±0.0331 mas[2]
Distance	1,260 ± 20 ly (385 ± 5 pc)
Details
Mass	0.59 ± 0.06[5] M☉
Radius	0.55 ± 0.11[5] R☉
Temperature	3820 ± 90[5] K
Metallicity [Fe/H]	0.13 ± 0.13[5] dex
Other designations
Gaia DR2 2053562475706063744, Kepler-45, KOI-254, KIC 5794240, 2MASS J19312949+4103513
Database references
SIMBAD	data
KIC	data

Kepler-45

The star is exhibiting strong starspot activity, with 4.1±2.5% of its surface covered by starspots.^[7]

Planetary system

The Kepler-45 planetary system^[8]

Companion (in order from star)	Mass	Semimajor axis (AU)	Orbital period (days)	Eccentricity	Inclination	Radius
b	0.5505 MJ	0.030	2.455239	—	—	11 R🜨

The "Hot Jupiter" class planet Kepler-45b,^[9] discovered in February 2011,^[10] is unusually massive for the M-class parent star.^[11] Its orbit is aligned within 11 degrees of rotational axis of the star.^[12]

The planet is strongly suspected to have optically thick rings, because its planetary shadow appears to be elongated.^[13]

See also

• NGTS-1b