A stellar fly-by close to the Galactic center: Can we detect stars on highly relativistic orbits?
The result's identifiers
Result code in IS VaVaI
<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F47813059%3A19240%2F18%3AA0000259" target="_blank" >RIV/47813059:19240/18:A0000259 - isvavai.cz</a>
Result on the web
<a href="https://onlinelibrary.wiley.com/doi/abs/10.1002/asna.201813499" target="_blank" >https://onlinelibrary.wiley.com/doi/abs/10.1002/asna.201813499</a>
DOI - Digital Object Identifier
<a href="http://dx.doi.org/10.1002/asna.201813499" target="_blank" >10.1002/asna.201813499</a>
Alternative languages
Result language
angličtina
Original language name
A stellar fly-by close to the Galactic center: Can we detect stars on highly relativistic orbits?
Original language description
The Galactic center Nuclear Star Cluster is one of the densest stellar clusters in the Galaxy. The stars in its inner portions orbit the supermassive black hole associated with the compact radio source Sgr A* at the orbital speeds of several thousand kilometers per second. The B-type star S2 is currently the best case to test the general relativity as well as other theories of gravity, based on its stellar orbit. Yet, its orbital period of approximate to 16years and the eccentricity of approximate to 0.88 yields the relativistic pericenter shift of approximate to 11', which is observationally still difficult to reliably measure due to possible Newtonian perturbations as well as reference-frame uncertainties. A naive way to solve this problem is to find stars with smaller pericenter distances, r_p <~ 1529 Schwarzschild radii (120 AU), and thus with more prominent relativistic effects. In this paper, we show that to detect stars on relativistic orbits is progressively less likely, given the volume shrinkage and the expected stellar density distributions. Finally, one arrives at a sparse region where the total number of bright stars is expected to fall below 1. One can, however, still potentially detect stars crossing this region. In this paper, we provide a simple formula for the detection probability of a star crossing a sparse region. We also examine an approximate timescale in which the star reappears in the sparse region, i.e., a 'waiting' timescale for observers.
Czech name
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Czech description
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Classification
Type
J<sub>imp</sub> - Article in a specialist periodical, which is included in the Web of Science database
CEP classification
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OECD FORD branch
10308 - Astronomy (including astrophysics,space science)
Result continuities
Project
<a href="/en/project/GJ16-03564Y" target="_blank" >GJ16-03564Y: Accretion configurations in strong gravity combined with electromagnetic field</a><br>
Continuities
P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)
Others
Publication year
2018
Confidentiality
S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů
Data specific for result type
Name of the periodical
Astronomische Nachrichten
ISSN
0004-6337
e-ISSN
1521-3994
Volume of the periodical
339
Issue of the periodical within the volume
5
Country of publishing house
DE - GERMANY
Number of pages
7
Pages from-to
324-330
UT code for WoS article
000444072500002
EID of the result in the Scopus database
2-s2.0-85053043867