[10][14] There is also a stellar activity cycle of 65 days, and possibly a second companion orbiting at a distance of at least 5 AU.
When the heavier star reached the end of the main sequence about 4.2–5.6 Gyr, it expanded until it dumped all of its mass onto the secondary and became a helium white dwarf.
8 Ursae Minoris is now in the red clump stage, and the planet will eventually be engulfed once it reaches the asymptotic giant branch.
[3] Research published in May 2024 used three different methods to determine the age of 8 Ursae Minoris and came up with an estimate of 1.9–3.5 Gyr.
This is much younger than the approximately 9 Gyr age required for the theory that the presence of the planet so close to 8 Ursae Minoris can be explained by a stellar merger.