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arXiv · 2104.10086

Precision Millimeter Astrometry of the $α$ Centauri AB System

Rachel Akeson·Charles Beichman·Pierre Kervella·Edward Fomalont·G. Fritz Benedict
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Abstract

$α$ Centauri A is the closest solar-type star to the Sun and offers the best opportunity to find and ultimately to characterize an Earth-sized planet located in its Habitable Zone (HZ). Here we describe initial results from an ALMA program to search for planets in the $α$ Cen AB system using differential astrometry at millimeter wavelengths. Our initial results include new absolute astrometric measurements of the proper motion, orbital motion, and parallax of the $α$ Cen system. These lead to an improved knowledge of the physical properties of both $α$ Cen A and B. Our estimates of ALMA's relative astrometric precision suggest that we will ultimately be sensitive to planets of a few 10s of Earth mass in orbits from 1-3 AU, where stable orbits are thought to exist.

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Rachel Akeson, Charles Beichman, Pierre Kervella, Edward Fomalont, G. Fritz Benedict. 2021-04-21. Precision Millimeter Astrometry of the $α$ Centauri AB System. https://doi.org/10.3847/1538-3881%2Fabfaff

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