This result was unexpected because no companion had been reported previously and because the star's previously known characteristics (such as
observed radial velocity variations) were incompatible with Arcturus as a binary system (R. F. Griffin, 1998).
Not exact matches
The planet was found with the
radial velocity method, a planet - hunting technique that relies upon slight
variations in the
velocity of a star to determine the gravitational pull exerted by nearby planets that are too faint to
observe directly with a telescope.
On March 25, 2015, a team of astronomers using the Hubble Space Telescope revealed observations which indicate via the transit method that Alpha Centauri B may have a second planet «c» in a hot inner orbit, just outside planet candidate «b.» After
observing Alpha Centauri B in 2013 and 2014 for a total of 40 hours, the team failed to detect any transits involving planet b (previously detected using the
radial velocity variations method and recently determined not to be
observed edge - on in a transit orbit around Star B).
Radial velocity observations from
observing runs in 2000 and 2004 reveal a periodic
variation of 3.30 ± 0.02 d, which is consistent with the previously determined value of 3.3125 ± 0.0002 d.