Open AccessLooking for Astrometric Signals below 20 m s−1: A Jupiter-mass Planet Signature in ε Eri
Author(s) -
В. В. Макаров,
N. Zacharias,
C Finch
Publication year - 2021
Publication title -
research notes of the aas
Language(s) - English
Resource type - Journals
ISSN - 2515-5172
DOI - 10.3847/2515-5172/ac0f59
Subject(s) - exoplanet , astrometry , physics , astronomy , jupiter (rocket family) , planet , radial velocity , stars , astrophysics , space exploration
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 yr. 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 yr ago.