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Related papers: The Angular Diameter of $\lambda$ Bo\"{o}tis}

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We determine the Galactic potential in the solar neigbourhood from RAVE observations. We select red clump stars for which accurate distances, radial velocities, and metallicities have been measured. Combined with data from the 2MASS and…

The abundance anomalies in lambda Boo stars are popularly explained by element-specific mass inflows at rates that are much greater than empirically-inferred bounds for interstellar accretion. Therefore, a lambda Boo star's thin outer…

Solar and Stellar Astrophysics · Physics 2015-11-11 M. Jura

Polarimetry is a novel tool to detect and characterize exoplanets and their atmospheres. Polarized scattered light from the non-transiting hot Jupiter $\upsilon$~And~b is measured to further constrain its orbit, mass, density, and…

Earth and Planetary Astrophysics · Physics 2011-09-15 S. V. Berdyugina , A. V. Berdyugin , V. Piirola

The rotational properties of the visible and dark components of low-mass disk galaxies (vrot<=100 km/s) are investigated using the Swaters sample. The rotational parameter lambda'=lambda_DM*(j_d/m_d) is determined, where lambda_DM is the…

Astrophysics · Physics 2007-05-23 Andreas Burkert

The diameter of a star is a major observable that serves to test the validity of stellar structure theories. It is also a difficult observable that is mostly obtained with indirect methods since the stars are so remote. Today only ~600…

Solar and Stellar Astrophysics · Physics 2016-04-27 Alain Chelli , Gilles Duvert , Laurent Bourgès , Guillaume Mella , Sylvain Lafrasse , Daniel Bonneau , Olivier Chesneau

We present angular size measurements of 22 oxygen-rich Mira variable stars. These data are part of a long term observational program using the Infrared Optical Telescope Array (IOTA) to characterize the observable behavior of these stars.…

Astrophysics · Physics 2009-11-07 G. T. van Belle , R. R. Thompson , M. J. Creech-Eakman

Lunar laser ranging (LLR) data and Apollo seismic data analyses, revealed independent evidence for the presence of a fluid lunar core. However, the size of the lunar fluid core remained uncertain by $\pm55$ km (encompassing two contrasting…

We compare the first direct angular diameter measurements obtained on our closest stellar neighbour, Alpha Centauri, to recent model diameters constrained by asteroseismic observations. Using the VINCI instrument installed at ESO's VLT…

Astrophysics · Physics 2011-05-23 P. Kervella , F. Thevenin , D. Segransan , G. Berthomieu , B. Lopez , P. Morel , J. Provost

We find the angular diameter of R Doradus to be 57 +/- 5 mas, exceeding that of Betelgeuse and implying that R Dor is larger in apparent size than every star except the Sun. R Dor is shown to be closely related to the Mira variables. We…

In this study we consider the nonlinear radial oscillations exciting in LBV--stars with effective temperatures 1.5e4 K <= Teff <= 3e4 K, bolometric luminosities 1.2e6 L_odot <= L <= 1.9e6 L_odot and masses 35.7 M_odot <= M <= 49.1 M_odot.…

Solar and Stellar Astrophysics · Physics 2015-05-13 Yu. A. Fadeyev

We study the structure of neutron stars in perturbative f(R) gravity models with realistic equations of state. We obtain mass-radius relations in a gravity model of the form f(R)=R+\alpha R^2. We find that deviations from the results of…

General Relativity and Quantum Cosmology · Physics 2015-05-18 A. Savas Arapoglu , Cemsinan Deliduman , K. Yavuz Eksi

We constrain cosmological parameters by analysing the angular power spectra of the Baryon Oscillation Spectroscopic Survey DR12 galaxies, a spectroscopic follow-up of around 1.3 million SDSS galaxies over 9,376 deg$^2$ with an effective…

We estimated 34 sets of Galactic model parameters for three intermediate latitude fields with Galactic longitudes l=60, l=90, and l=180, and we discussed their dependence on the volume. Also, we confirmed the variation of these parameters…

Astrophysics · Physics 2009-11-13 S. Karaali , S. Bilir , E. Yaz , E. Hamzaoglu , R. Buser

Recent numerical simulations in general relativistic magnetohydrodynamics (GRMHD) provide useful constraints for the interpretation of the GW170817 discovery. Combining the observed data with these simulations leads to a bound on the…

High Energy Astrophysical Phenomena · Physics 2018-05-08 Milton Ruiz , Stuart L. Shapiro , Antonios Tsokaros

There are indications that gravity is asymptotically safe. The Standard Model (SM) plus gravity could be valid up to arbitrarily high energies. Supposing that this is indeed the case and assuming that there are no intermediate energy scales…

High Energy Physics - Theory · Physics 2010-05-07 Mikhail Shaposhnikov , Christof Wetterich

Recently, cosmology has seen a surge in alternative models that purport to solve the discrepancy between the values of the Hubble constant $H_0$ as measured by cosmological microwave background anisotropies and local supernovae,…

Cosmology and Nongalactic Astrophysics · Physics 2024-04-01 Jonas El Gammal , Sven Günther , Emil Brinch Holm , Andreas Nygaard

Model stellar atmospheres are fundamental tools for understanding stellar observations from interferometry, microlensing, eclipsing binaries and planetary transits. However, the calculations also include assumptions, such as the geometry of…

Solar and Stellar Astrophysics · Physics 2015-06-15 Hilding R. Neilson , John B. Lester

One of the most common assumptions has been made that the pressure inside the star is isotropic in nature. However, the pressure is locally anisotropic in nature which is a more realistic case. In this study, we investigate certain…

General Relativity and Quantum Cosmology · Physics 2022-11-18 H. C. Das

The morpho-kinematics of the circumstellar envelope of oxygen-rich AGB star R Leonis is probed using ALMA (Atacama Large Millimeter/submillimeter Array) observations of the emission of molecular lines, including in particular CO(2-1) and…

Solar and Stellar Astrophysics · Physics 2022-11-16 D. T. Hoai , P. T. Nhung , M. N. Tan , P. Darriulat , P. N. Diep , N. B. Ngoc , T. T. Thai , P. Tuan-Anh

Here we present a kinematic study of the Galactic halo out to a radius of $\sim$ 60 kpc, using 4664 blue horizontal branch (BHB) stars selected from the SDSS/SEGUE survey, to determine key dynamical properties. Using a maximum likelihood…

Astrophysics of Galaxies · Physics 2012-12-04 Prajwal R. Kafle , Sanjib Sharma , Geraint F. Lewis , Joss Bland-Hawthorn