Precision Millimeter Astrometry of the α Centauri AB System
Abstract
Alpha 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. Here, we describe initial results from an Atacama Large Millimeter/submillimeter Array (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 tens of Earth mass in orbits from 1 to 3 au, where stable orbits are thought to exist.
Additional Information
© 2021 The American Astronomical Society. Received 2020 October 26; revised 2021 April 20; accepted 2021 April 21; published 2021 June 14. This paper makes use of the following ALMA data: ADS/JAO.ALMA #2018.1.00557.S. ALMA is a partnership of ESO (representing its member states), NSF (USA) and NINS (Japan), together with NRC (Canada), MOST and ASIAA (Taiwan), and KASI (Republic of Korea), in cooperation with the Republic of Chile. The Joint ALMA Observatory is operated by ESO, AUI/NRAO, and NAOJ. The National Radio Astronomy Observatory is a facility of the National Science Foundation operated under cooperative agreement by Associated Universities, Inc. Some of the research described in this publication was carried out in part at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration. G.F.B. thanks McDonald Observatory for extending a Research Fellow position, allowing continued possession of an office and computing equipment. We thank the referees for a careful reading of the paper and for making many useful suggestions to clarify the material. Facilities: ALMA - Atacama Large Millimeter Array, ESO:3.6 m(HARPS). - Software: CASA (McMullin et al. 2007), astropy (Astropy Collaboration et al. 2013, 2018).Attached Files
Published - Akeson_2021_AJ_162_14.pdf
Accepted Version - 2104.10086.pdf
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Additional details
- Eprint ID
- 109557
- Resolver ID
- CaltechAUTHORS:20210623-175249522
- NASA/JPL/Caltech
- McDonald Observatory
- Created
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2021-06-23Created from EPrint's datestamp field
- Updated
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2021-06-23Created from EPrint's last_modified field
- Caltech groups
- Infrared Processing and Analysis Center (IPAC)