In this article, we suggest a Sitter model in favor of compact stars in low-mass X-ray binaries.Here, we have considered the presence of a cosmological constant(on a small scale) to investigate the stellar structure. ...In this article, we suggest a Sitter model in favor of compact stars in low-mass X-ray binaries.Here, we have considered the presence of a cosmological constant(on a small scale) to investigate the stellar structure. We conclude that this approach is very suitable for the familiar physical model of compact stars in low-mass X-ray binaries. We calculate the probable radius, compactness(u) and surface redshift(Z_s) of six compact stars in low-mass X-ray binaries, namely Cyg X-2, V395 Carinae/2 S 0921–630, XTE J2123–058,X1822–371(V691 CrA), 4 U 1820–30 and GR Mus(XB 1254–690). We also offer a possible equation of state(EOS) for the stellar objects.展开更多
Based on the photographic and CCD observations of the relative motion of the A and B components of the binary system ADS 9346 obtained with the 26-inch refractor of Pulkovo Observatory during 1979–2019,we discover an...Based on the photographic and CCD observations of the relative motion of the A and B components of the binary system ADS 9346 obtained with the 26-inch refractor of Pulkovo Observatory during 1979–2019,we discover an invisible companion associated with star A.Comparison of the ephemerides with the positional and spectroscopic observations allowed us to calculate the preliminary orbit of the photocenter(P=15 yr).The minimal mass of the companion is approximately 0.13 M.The existence of the invisible low-mass companion is implied by the IR-excess based on IRAS data.To confirm this,additional observations of the radial velocity near the periastron need to be carried out.展开更多
文摘In this article, we suggest a Sitter model in favor of compact stars in low-mass X-ray binaries.Here, we have considered the presence of a cosmological constant(on a small scale) to investigate the stellar structure. We conclude that this approach is very suitable for the familiar physical model of compact stars in low-mass X-ray binaries. We calculate the probable radius, compactness(u) and surface redshift(Z_s) of six compact stars in low-mass X-ray binaries, namely Cyg X-2, V395 Carinae/2 S 0921–630, XTE J2123–058,X1822–371(V691 CrA), 4 U 1820–30 and GR Mus(XB 1254–690). We also offer a possible equation of state(EOS) for the stellar objects.
基金RFBR according to the research projects 19-02-00843 A and 20-02-00563 A and with partial support of the grant 075-15-2020-780 from the Government of the Russian Federation and the Ministry of Higher Education and Science。
文摘Based on the photographic and CCD observations of the relative motion of the A and B components of the binary system ADS 9346 obtained with the 26-inch refractor of Pulkovo Observatory during 1979–2019,we discover an invisible companion associated with star A.Comparison of the ephemerides with the positional and spectroscopic observations allowed us to calculate the preliminary orbit of the photocenter(P=15 yr).The minimal mass of the companion is approximately 0.13 M.The existence of the invisible low-mass companion is implied by the IR-excess based on IRAS data.To confirm this,additional observations of the radial velocity near the periastron need to be carried out.
