BD+14 4559 b, named Pirx, is an exoplanet orbiting the K-type main sequence star BD+14 4559 about 161 light-years (49 parsecs, or nearly 1.5×1015 km) from Earth in the constellation Pegasus.
The exoplanet was found by using the radial velocity method, from radial-velocity measurements via observation of Doppler shifts in the spectrum of the planet's parent star.
In comparison, the Sun is about 4.6 billion years old[4] and has a surface temperature of 5778 K.[5] The star's apparent magnitude, or how bright it appears from Earth's perspective, is 9.63.
[citation needed] The search for BD+14 4559 b started when its host star was chosen an ideal target for a planet search using the radial velocity method (in which the gravitational pull of a planet on its star is measured by observing the resulting Doppler shift), as stellar activity would not overly mask or mimic Doppler spectroscopy measurements.
[1] The net result was an estimate of a 1.47 MJ planetary companion orbiting the star at a distance of 0.77 AU with an eccentricity of 0.29.