2021/07/02 by Valeri V. Makarov, Makarov, Valeri V., Norbert Zacharias +3 · 1 voice
Physics and Astronomy · #Earth and Planetary Astrophysics (astro-ph.EP) #FOS: Physical sciences #Solar and Stellar Astrophysics (astro-ph.SR) #astro-ph.EP #astro-ph.SR
paper · pdf · doi:10.48550/arxiv.2107.01090
The USNO ground-based astrometric program URAT-Bright in combination with the Hipparcos mission epoch astrometry provides precise proper motions of a thousand bright stars in the southern hemisphere on a time basis of about 25 years. Small but statistically significant differences between these proper motions and Gaia EDR3 data can reveal long-period exoplanets similar to Jupiter in the nearest star systems. The presence of such a planet orbiting the magnetically active dwarf ε Eri is confirmed from both URAT--Hipparcos--EDR3 data and Hipparcos--EDR3 data with a corresponding projected velocity of (+5,+8) and (+6,+13) m s-1, respectively. These signals are formally significant at a 0.989 and 1.0 confidence. We conclude that the newest astrometric results confirm the existence of a long-period exoplanet orbiting ε Eri, which was marginally detected from precision radial velocity measurements some 20 years ago.