scholarly journals Testing gravity with wide binary stars like α Centauri

2018 ◽  
Vol 480 (2) ◽  
pp. 2660-2688 ◽  
Author(s):  
Indranil Banik ◽  
Hongsheng Zhao
Keyword(s):  
1997 ◽  
Vol 485 (2) ◽  
pp. 785-788 ◽  
Author(s):  
Mauri J. Valtonen
Keyword(s):  

Nature ◽  
2012 ◽  
Vol 492 (7428) ◽  
pp. 191-192
Author(s):  
Keivan Guadalupe Stassun
Keyword(s):  

Author(s):  
С.А. Сапожников ◽  
Д.А. Ковалева

По данным Gaia DR2 в радиусе 100 пк от Солнца исследованы двойные звезды с общим собственным движением до расстояния между компонентами 3 пк. Для исключения возможных случайных совпадений смоделирована искусственная выборка случайных пар. Показано, что принятый способ отбора пар с общим собственным движением делает загрязнение выборки случайными совпадениями незначительным даже при больших расстояниях между компонентами; величина такого загрязнения оценена численно. Получено бимодальное распределение по логарифму расстояния между компонентами, демонстрирующее для очень широких пар минимум, связанный с распадом систем, на расстоянии ≈ 0.5 пк, и дальнейший рост, формируемый распавшимися, медленно расходящимися компонентами. Binary and common proper motion stars within 100 pc of the Sun are being investigated using Gaia DR2 data. An artificial random pairs sample is constructed to exclude possible random pairing contamination. Numerical estimation of this contamination shows that the chosen method to select the common proper motion stars yields little contamination even at high separations. In a logarithmic scale the separation distribution appear to have a minimum at ≈ 0.5 pc, most likely related to binary star dissolution, with further increase formed by dissolved, slowly distancing components.


2019 ◽  
Vol 488 (4) ◽  
pp. 4740-4752 ◽  
Author(s):  
Charalambos Pittordis ◽  
Will Sutherland

ABSTRACT Several recent studies have shown that very wide binary stars can potentially provide an interesting test for modified-gravity theories which attempt to emulate dark matter; these systems should be almost Newtonian according to standard dark-matter theories, while the predictions for MOND-like theories are distinctly different, if the various observational issues can be overcome. Here we explore an observational application of the test from the recent Gaia DR2 data release: we select a large sample of ∼24 000 candidate wide binary stars with distance $\lt 200 \, {\rm pc}$ and magnitudes G < 16 from Gaia DR2, and estimated component masses using a main-sequence mass–luminosity relation. We then compare the frequency distribution of pairwise relative projected velocity (relative to circular-orbit value) as a function of projected separation; these distributions show a clear peak at a value close to Newtonian expectations, along with a long ‘tail’ which extends to much larger velocity ratios; the ‘tail’ is considerably more numerous than in control samples constructed from DR2 with randomized positions, so its origin is unclear. Comparing the velocity histograms with simulated data, we conclude that MOND-like theories without an external field effect (ExFE) are strongly inconsistent with the observed data since they predict a peak-shift in clear disagreement with the data; testing MOND-like theories with an ExFE is not decisive at present, but has good prospects to become decisive in future with improved modelling or understanding of the high-velocity tail, and additional spectroscopic data.


2018 ◽  
Vol 853 (1) ◽  
pp. 59 ◽  
Author(s):  
Riley W. Clarke ◽  
James R. A. Davenport ◽  
Kevin R. Covey ◽  
Christoph Baranec

2017 ◽  
Vol 608 ◽  
pp. A116 ◽  
Author(s):  
J. A. Correa-Otto ◽  
R. A. Gil-Hutton
Keyword(s):  

Nature ◽  
2013 ◽  
Vol 493 (7432) ◽  
pp. 381-384 ◽  
Author(s):  
Nathan A. Kaib ◽  
Sean N. Raymond ◽  
Martin Duncan

2010 ◽  
Vol 401 (2) ◽  
pp. 977-994 ◽  
Author(s):  
Yan-Fei Jiang ◽  
Scott Tremaine
Keyword(s):  

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