Kepler-45
M-type star in the constellation Cygnus
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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 19h 31m 29.495s, 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.
| 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 | |
| Evolutionary stage | main sequence[2] |
| 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 | |
| Kepler-45, KOI-254, KIC 5794240, 2MASS J19312949+4103513, Gaia DR2 2053562475706063744 | |
| Database references | |
| SIMBAD | data |
| KIC | data |
The star is exhibiting strong starspot activity, with 4.1±2.5% of its surface covered by starspots.[7]
Planetary system
| 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]
Kepler-45b's transit lightcurve appears to deviate from what would be expected of a spherical planet. The deviation could be caused by material surrounding the planet, such as a dusty shell from an escaping atmosphere or a dense exoring.[13]