Directly testing gravity with Proxima Centauri

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216208%3A11320%2F19%3A10406394" target="_blank" >RIV/00216208:11320/19:10406394 - isvavai.cz</a>

Výsledek na webu

<a href="https://verso.is.cuni.cz/pub/verso.fpl?fname=obd_publikace_handle&handle=.gJv0ijUcQ" target="_blank" >https://verso.is.cuni.cz/pub/verso.fpl?fname=obd_publikace_handle&handle=.gJv0ijUcQ</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1093/mnras/stz1379" target="_blank" >10.1093/mnras/stz1379</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Directly testing gravity with Proxima Centauri

Popis výsledku v původním jazyce

The wide binary orbit of Proxima Centauri around alpha Centauri A and B differs significantly between Newtonian and Milgromian dynamics (MOND). By combining previous calculations of this effect with mock observations generated using a Monte Carlo procedure, we show that this prediction can be tested using high precision astrometry of Proxima Centauri. This requires approximate to 10 yr of observations at an individual epoch precision of 0.5 mu as, within the design specifications of the proposed Theia mission. In general, the required duration should scale as the 2/ 5 power of the astrometric precision. A long-period planet could produce a MOND-like astrometric signal, but only if it has a particular ratio of mass to separation squared and a sky position close to the line segment connecting Proxima Centauri with alpha Centauri. Uncertainties in perspective effects should be small enough for this test if the absolute radial velocity of Proxima Centauri can be measured to within approximate to 10 ms(-1), better than the present accuracy of 32 ms(-1). We expect the required improvement to become feasible using radial velocity zero-points estimated from larger samples of close binaries, with the Sun providing an anchor. We demonstrate that possible astrometric microlensing of Proxima Centauri is unlikely to affect the results. We also discuss why it should be possible to find sufficiently astrometrically stable reference stars. Adequately, addressing these and other issues would enable a decisive test of gravity in the currently little explored low acceleration regime relevant to the dynamical discrepancies in galactic outskirts.

Název v anglickém jazyce

Directly testing gravity with Proxima Centauri

Popis výsledku anglicky

The wide binary orbit of Proxima Centauri around alpha Centauri A and B differs significantly between Newtonian and Milgromian dynamics (MOND). By combining previous calculations of this effect with mock observations generated using a Monte Carlo procedure, we show that this prediction can be tested using high precision astrometry of Proxima Centauri. This requires approximate to 10 yr of observations at an individual epoch precision of 0.5 mu as, within the design specifications of the proposed Theia mission. In general, the required duration should scale as the 2/ 5 power of the astrometric precision. A long-period planet could produce a MOND-like astrometric signal, but only if it has a particular ratio of mass to separation squared and a sky position close to the line segment connecting Proxima Centauri with alpha Centauri. Uncertainties in perspective effects should be small enough for this test if the absolute radial velocity of Proxima Centauri can be measured to within approximate to 10 ms(-1), better than the present accuracy of 32 ms(-1). We expect the required improvement to become feasible using radial velocity zero-points estimated from larger samples of close binaries, with the Sun providing an anchor. We demonstrate that possible astrometric microlensing of Proxima Centauri is unlikely to affect the results. We also discuss why it should be possible to find sufficiently astrometrically stable reference stars. Adequately, addressing these and other issues would enable a decisive test of gravity in the currently little explored low acceleration regime relevant to the dynamical discrepancies in galactic outskirts.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10308 - Astronomy (including astrophysics,space science)

Projekt

—

Návaznosti

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Rok uplatnění

2019

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

Monthly Notices of the Royal Astronomical Society

ISSN

0035-8711

e-ISSN

—

Svazek periodika

487

Číslo periodika v rámci svazku

2

Stát vydavatele periodika

GB - Spojené království Velké Británie a Severního Irska

Počet stran výsledku

9

Strana od-do

1653-1661

Kód UT WoS článku

000474919700011

EID výsledku v databázi Scopus

2-s2.0-85070106494