Magnitude 8.04 Apparent magnitude (V) 8.04 | ||
People also search for HD 210702, Chi Pegasi, Rho Pegasi | ||
HD 219828 is an 8th magnitude star approximately 265 light years away in the constellation of Pegasus. It is a yellow subgiant, meaning that hydrogen fusion has ceased in its core.
Planetary system
In 2007, a Neptune-mass planet was found orbiting the star by Melo. According to the author, assuming an Earth-like rocky composition, the planet could yield a radius 2.2 times that of Earth. This could be furtherly proved if transit were observed, though, as authors state, it is a difficult task. At this point, it was suggested that a best fit orbital solution hints the presence of an additional planetary companion (so far unconfirmed) with 70% of Jupiter's mass, likely orbital separation of 0.68 Astronomical units and eccentric orbit (e=0.3). However, in 2016, further analysis or radial velocity data confirmed the presence of an outer planet larger and more eccentric than was originally believed. With high eccentricity and a high mass ratio between the two planets, the system is quite unique. The planet c is also a potential target for GAIA astrometry or atmospheric characterization using direct imaging or high-resolution spectroscopy.