Kepler-296d

Kepler-296d is an exoplanet orbiting the M-dwarf star Kepler-296,¹²³ located in the constellation Draco.⁴ It was discovered in 2014 by the Kepler space telescope using the transit method.¹⁵

Kepler-296d has a radius approximately 2.09 times¹ that of Earth and a mass estimated at 5.02¹⁴ Earth masses, placing it in the category of Neptune-like exoplanets. The planet orbits its host star every 19.9 days at a distance of approximately 0.118 AU.¹⁵ Its orbit has an eccentricity of less than 0.33.⁵

The host star, Kepler-296, is an M-type dwarf.² These stars are cooler and smaller than the Sun, and often host multiple exoplanets. Kepler-296 is known to host at least five planets.¹³

Kepler-296d was identified in 2014¹ as part of the data collected by NASA's Kepler space telescope, which monitored the brightness of over 150,000 stars⁶ to detect periodic dips in light indicative of planetary transits. The detection of Kepler-296d was achieved through the transit method,¹⁵ wherein a planet passes between its host star and the observer, causing a measurable decrease in the star’s apparent brightness.