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Related papers: On the Galactic aberration constant

200 papers

In this work, we obtain Hubble constant ($H_0$) estimates by using two galaxy cluster gas mass fraction measurement samples, Type Ia supernovae luminosity distances, and the validity of the cosmic distance duality relation. Notably, the…

Cosmology and Nongalactic Astrophysics · Physics 2024-09-09 Javier E. Gonzalez , Marcelo Ferreira , Leorando R. Colaço , Rodrigo F. L. Holanda , Rafael C. Nunes

It is now recognised that the traditional method of calculating the LSR fails. We find an improved estimate of the LSR by making use of the larger and more accurate database provided by XHIP and repeating our preferred analysis from Francis…

Astrophysics of Galaxies · Physics 2014-05-13 Charles Francis , Erik Anderson

The current state of research of the Galactic magnetic field is reviewed critically. The average (equipartition) strength of the total field derived from radio synchrotron data is 6 +/- 2 muG locally and about 10 +/- 3 muG at 3 kpc Galactic…

Astrophysics · Physics 2021-04-28 Rainer Beck

A new approach to determining the solar galactocentric distance, $R_0$, from the geometry of spiral-arm segments is proposed. Geometric aspects of the problem are analyzed and a simplified three-point method for estimating $R_0$ from…

Astrophysics of Galaxies · Physics 2018-03-14 I. I. Nikiforov , A. V. Veselova

We have identified seven (field) elliptical galaxies acting as strong gravitational lenses and have used them to measure cosmological parameters. To find the most likely value for Omega_m (= Omega_matter) and Lambda, we have used the…

Astrophysics · Physics 2009-10-28 Myungshin Im , Richard E. Griffiths , Kavan U. Ratnatunga

The highly-accurate optical reference frame GCRF (Gaia Celestial Reference Frame) is expected to be available in several years. By the same time, a new version of radio reference frame ICRF (International Celestial Reference Frame) will be…

Instrumentation and Methods for Astrophysics · Physics 2015-10-06 Zinovy Malkin

We use recently updated globular cluster distances to estimate the distance to the Galactic centre, finding 7.4 \pm 0.2|stat \pm 0.2|sys kpc from symmetry considerations. We recalibrate the red clump magnitude from Hipparcos stars, finding…

Astrophysics of Galaxies · Physics 2014-05-13 Charles Francis , Erik Anderson

The influence of various factors on the statistical properties of the Galactic center distance ($R_0$) estimate obtained by solving the general problem of determining the geometric parameters of a Galactic spiral arm from its segment with…

Astrophysics of Galaxies · Physics 2018-11-19 I. I. Nikiforov , A. V. Veselova

In this paper we directly constrain possible spatial variations of the Newtonian gravitational constant G over ranges 0.01-5 AU in various extrasolar multi-planet systems. By means of the third Kepler's law we determine the quantity \Gamma_…

General Relativity and Quantum Cosmology · Physics 2013-10-09 Lorenzo Iorio

The distance to the Galactic center $R_0$ is a fundamental parameter for understanding the Milky Way, because all observations of our Galaxy are made from our heliocentric reference point. The uncertainty in $R_0$ limits our knowledge of…

Astrophysics of Galaxies · Physics 2022-12-14 Henry W. Leung , Jo Bovy , J. Ted Mackereth , Jason A. S. Hunt , Richard R. Lane , John C. Wilson

The Oort constants describe the local variations of the stellar streaming field. Classically, they are determined from stellar proper motions. We discuss problems arising in this procedure. A large, hitherto overlooked, source of systematic…

Astrophysics · Physics 2009-11-07 Rob P. Olling , Walter Dehnen

In this paper we derive a bound on the rate of change of the gravitational constant G coming from the pulsating white dwarf G117-B15A. This star is a ZZ Ceti pulsator extensively studied with astroseismological techniques for last three…

Astrophysics · Physics 2009-11-07 Marek Biesiada , Beata Malec

Our recent studies of axial-symmetry breaking in the nearby ($d <3 \,{\rm kpc}$) star counts are sensitive to the distortions of stellar orbits perpendicular and parallel to the orientation of the bar just within and beyond the outer…

Astrophysics of Galaxies · Physics 2020-08-20 Austin Hinkel , Susan Gardner , Brian Yanny

The rotation curve (RC) of our Galaxy, the Milky Way, is constructed starting from its very inner regions (few hundred pc) out to a large Galactocentric distance of $\sim 200$ kpc using kinematical data on a variety of tracer objects moving…

Astrophysics of Galaxies · Physics 2015-06-17 Pijushpani Bhattacharjee , Soumini Chaudhury , Susmita Kundu

As part our investigation into the Galactic rotation curve, we carried out Very Long Baseline Interferometry (VLBI) observations towards the star-forming region IRAS 01123+6430 using VLBI Exploration of Radio Astrometry (VERA) to measure…

Eisenhauer et al. (2003, 2005) derived absolute (geometrical) estimates of the distanceto the center of the Galaxy, $R_0$, from the star S2 orbit around Sgr A* on the assumption that the intrinsic velocity of Sgr A* is negligible. This…

Astrophysics · Physics 2008-03-07 Igor' I. Nikiforov

We consider the application of quantum corrections computed using renormalization group arguments in the astrophysical domain and show that, for the most natural interpretation of the renormalization group scale parameter, a gravitational…

Cosmology and Nongalactic Astrophysics · Physics 2014-11-20 Davi C. Rodrigues , Patricio S. Letelier , Ilya L. Shapiro

A decreasing gravitational constant, G, coupled with angular momentum conservation is expected to increrase a planetary semimajor axis, a, as \dot a/a=-\dot G/G. Analysis of lunar laser ranging data strongly limits such temporal variations…

General Relativity and Quantum Cosmology · Physics 2008-11-26 James G. Williams , Slava G. Turyshev , Dale H. Boggs

We have reconstructed possible orbits for a collection of stars located within 0.5 arcsec of Sgr A*. These orbits are constrained by observed stellar positions and angular proper motions. The construction of such orbits serves as a baseline…

Astrophysics · Physics 2009-10-31 P. C. Fragile , G. J. Mathews

We conducted astrometric VLBI observations of water-vapor maser emission in the massive star forming region IRAS 21379+5106 to measure the annual parallax and proper motion, using VERA. The annual parallax was measured to be $0.262 \pm…