Published December 1, 2020 | Version v1
Journal article

The Short-period S-stars S4711, S62, S4714 and the Lense–Thirring Effect due to the Spin of Sgr A*

  • 1. Ministero dell'Istruzione, dell'Università e della Ricerca (M.I.U.R.), Viale Unità di Italia 68, I-70125, Bari (Italy)

Description

Recently, some S-stars (S4711, S62, S4714) orbiting the supermassive black hole (SMBH) in Sgr A* with short orbital periods (7.6 yr ≤ P b ≤ 12 yr) were discovered. It was suggested that they may be used to measure the general relativistic Lense–Thirring (LT) precessions of their longitudes of ascending node Ω induced by the SMBH's angular momentum J . In fact, the proposed numerical estimates hold only in the particular case of a perfect alignment of J with the line of sight, which does not seem to be the case. Moreover, the inclination I and the argument of perinigricon ω also undergo LT precessions for an arbitrary orientation of J in space. We explicitly show the analytical expressions of I ˙ L T , Ω ˙ L T , ω L T in terms of the SMBH's spin polar angles i ε . It turns out that the LT precessions, in arcseconds per year ( y r 1 ), range within | I ˙ L T | 7 y r 1 , | Ω ˙ L T | 9 y r 1 , and 13 y r 1 ω ˙ L T 14 y r 1 for S4714, | I ˙ L T | 5 y r 1 , | Ω ˙ L T | 5 y r 1 , and | ω ˙ L T | 10 y r 1 for S62, and | I ˙ L T | 0.3 y r 1 , | Ω ˙ L T | 0.3 y r 1 , and | ω ˙ L T | 0.7 y r 1 for S4711. For each star, the corresponding values of i max , ε max , and i min , ε min are determined as well, along with those i 0 , ε 0 that cancel the LT precessions. The LT perinigricon precessions ω ˙ L T are overwhelmed by the systematic uncertainties in the Schwarzschild ones due to the current errors in the stars' orbital parameters and the mass of Sgr A* itself.

Availability note (English)

Available from http://dx.doi.org/10.3847/1538-4357/abbfb5

Additional details

Identifiers

Publishing Information

Journal Title
Astrophysical Journal
Journal Volume
904
Journal Issue
2
Journal Page Range
[5 p.]
ISSN
0004-637X
CODEN
ASJOAB

INIS

Country of Publication
United Kingdom
Country of Input or Organization
International Atomic Energy Agency (IAEA)
INIS RN
52072233
Subject category
S79: ASTROPHYSICS, COSMOLOGY AND ASTRONOMY;
Descriptors DEI
ANALYTICAL SOLUTION; ANGULAR MOMENTUM; BLACK HOLES; MASS; PRECESSION; RELATIVISTIC RANGE; SIMULATION; SPIN ORIENTATION; STARS; THIRRING MODEL
Descriptors DEC
ENERGY RANGE; MATHEMATICAL SOLUTIONS; ORIENTATION