M-type star in the constellation Cygnus
! style="text-align: center; background-color: #FFFFC0;" colspan="2" | Observation dataEpoch J2000      Equinox J2000
! style="text-align:left" | Constellation
! style="text-align:left" | Right ascension
! style="text-align:left" | Declination
! style="text-align:left" | Apparent magnitude (V)
! style="background-color: #FFFFC0; text-align: center;" colspan="2"| Characteristics
! style="text-align:left" | Spectral type
! style="text-align:left" | U−B 
! style="text-align:left" | B−V 
! style="text-align:left" | V−R 
! style="text-align:left" | R−I 
! style="text-align:left" | Variable type
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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 ° 03′ 51.37″. With an apparent visual magnitude of 16.88, this star is too faint to be seen with the naked eye.
The star is exhibiting strong starspot activity, with 4.1±2.5% of its surface covered by starspots.
Planetary system.
! align=center| Companion
! align=center| Mass
! align=center| Semimajor axis
! align=center| Orbital period
! align=center| Eccentricity
! align=center| Inclination
! align=center| Radius
The "Hot Jupiter" class planet Kepler-45b, discovered in February 2011, is unusually massive for the M-class parent star. Its orbit is aligned within 11 degrees of rotational axis of the star.
The planet is strongly suspected to have optically thick rings, because its planetary shadow appears to be elongated.
References.
 ;templatestyles src="Reflist/styles.css" / ;
 ;indicator name="01-sky-coordinates" ; ;templatestyles src="Template:Sky/styles.css" / ;Coordinates: &amp;zoom=&amp;show_grid=1&amp;show_constellation_lines=1&amp;show_constellation_boundaries=1&amp;show_const_names=1&amp;show_galaxies=1&amp;img_source=IMG_all 19h 31m 29.495s, +41° 03′ 51.37″ ;/indicator ;