Proxima Centauri: a transitional modified Newtonian dynamics controlled orbital candidate?

• Published in: Monthly notices of the Royal Astronomical Society. Letters Vol. 399; no. 1; pp. L21 - L23
• Main Author: Beech, Martin
• Format: Journal Article
• Language: English
• Published: Oxford, UK Blackwell Science Ltd 01.10.2009; Blackwell Publishing Ltd
• Subjects: gravitation; stars: individual: Proxima; stars: kinematics
• ISSN: 1745-3925; 1745-3933
• DOI: 10.1111/j.1745-3933.2009.00718.x

The triple-system candidacy of Proxima Centauri with α Centauri A/B is reviewed in terms of its potential to demonstrate an orbit controlled according to modified Newtonian dynamics (MOND). It is noted that Proxima is already sufficiently distant from α Cen A/B that MOND corrections to its speed and orbit should be present and therefore potentially measurable. It is argued that present-day observations of the Proxima–α Centauri A/B system do not rule out the possibility that Proxima occupies a low-eccentricity orbit with an orbital period of the order of a few million years.