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Related papers: White dwarfs in an ungravity-inspired model

200 papers

Recently, it has been shown by S.~M. de Carvalho et al. (2014) that the deviations between the degenerate case and observations were already evident for 0.7-0.8 M$_{\odot}$ white dwarfs. Such deviations were related to the neglected effects…

Solar and Stellar Astrophysics · Physics 2016-04-13 Kuantay Boshkayev , Jorge A. Rueda , Bakytzhan Zhami , Zhanerke Kalymova , Galymdin Balgymbekov

The masses of compact objects like white dwarfs, neutron stars and black holes are fundamental to astrophysics, but very difficult to measure. We present the results of an analysis of subluminous B (sdB) stars in close binary systems with…

Astrophysics · Physics 2008-04-09 S. Geier , C. Karl , H. Edelmann , U. Heber , R. Napiwotzki

We conducted a search for new ultracool companions to nearby white dwarfs using multiple methods, including the analysis of colors and examination of images in both the optical and the infrared. Through this process, we identified fifty-one…

White dwarfs are excellent research laboratories as they reach temperatures, pressures, and magnetic fields that are unattainable on Earth. To better understand how these three physical parameters interact with each other and with other…

Solar and Stellar Astrophysics · Physics 2023-02-22 L. L. Amorim , S. O. Kepler , Baybars Külebi , S. Jordan , A. D. Romero

I compare the dark matter content within stellar half-mass radius expected in a $\Lambda$CDM-based galaxy formation model with existing observational estimates for the observed dwarf satellites of the Milky Way and ultra-diffuse galaxies…

Astrophysics of Galaxies · Physics 2024-12-19 Andrey Kravtsov

A White Dwarf (WD) star and a main-sequence companion may interact through their different stellar evolution stages. This sort of binary population has historically helped us improve our understanding of binary formation and evolution…

High Energy Astrophysical Phenomena · Physics 2019-01-30 Ali Taani

Short-period Galactic double white dwarf (DWD) systems will be observable both in visible light through photometric monitoring and in mHz-range gravitational waves (GWs) with forthcoming space-based laser interferometry such as LISA. When…

Solar and Stellar Astrophysics · Physics 2025-08-06 Nathaniel Leslie , Liang Dai , Kevin Burdge

WD 1145+017 is a unique white dwarf system that has a heavily polluted atmosphere, an infrared excess from a dust disk, numerous broad absorption lines from circumstellar gas, and changing transit features, likely from fragments of an…

This paper is the third in a series on tests of gravity using observations of stars and nearby dwarf galaxies. We carry out four distinct tests using published data on the kinematics and morphology of dwarf galaxies, motivated by the…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-15 Vinu Vikram , Anna Cabre , Bhuvnesh Jain , Jake VanderPlas

Many open clusters have a deficit of observed white dwarfs (WDs) compared with predictions of the number of stars to have evolved into WDs. We evaluate the number of WDs produced in open clusters and the number of those WDS detectable using…

Astrophysics · Physics 2009-11-10 Kurtis A. Williams

The masses of compact objects like white dwarfs, neutron stars and black holes are fundamental to astrophysics, but very difficult to measure. We present the results of an analysis of subluminous B (sdB) stars in close binary systems with…

Astrophysics · Physics 2007-05-23 S. Geier , C. Karl , H. Edelmann , U. Heber , R. Napiwotzki

We show that recently proposed white dwarf models with masses well in excess of the Chandrasekhar limit, based on modifying the equation of state by a super-strong magnetic field in the centre, are very far from equilibrium because of the…

Solar and Stellar Astrophysics · Physics 2015-02-10 Rajaram Nityananda , Sushan Konar

Static and uniformly rotating, cold and hot white dwarfs are investigated both in Newtonian gravity and general theory of relativity, employing the well-known Chandrasekhar equation of state. The mass-radius, mass-central density,…

Solar and Stellar Astrophysics · Physics 2020-06-04 Kuantay Boshkayev

Coalescences of binary white dwarfs represent a copious source of information for gravitational wave interferometers operating in the decihertz band. Moreover, according to the double degenerate scenario, they have been suggested to be…

High Energy Astrophysical Phenomena · Physics 2020-03-18 Andrea Maselli , Stefania Marassi , Marica Branchesi

The mass radius relationship of white dwarfs, near the Chandrasekhar Limit, is derived for a toy model of uniform density, using the variational principle. A power law scaling, reminiscent of those found in 2nd order phase transitions, is…

Astrophysics · Physics 2007-05-23 Sayan Chakraborti

We investigate the old open cluster M67 using ultraviolet photometric data of Ultra-Violet Imaging Telescope in multi-filter far-UV bands. M67, well known for the presence of several blue straggler stars (BSS), has been put to detailed…

The coupling of the electromagnetic field directly with gravitational gauge fields leads to new physical effects that can be tested using astronomical data. Here we consider a particular case for closer scrutiny, a specific nonminimal…

General Relativity and Quantum Cosmology · Physics 2009-11-10 Oliver Preuss , Mark P. Haugan , Sami K. Solanki , Stefan Jordan

We revisit in this work the problem of the maximum masses of magnetized White Dwarfs (WD). The impact of a strong magnetic field onto the structure equations is addressed. The pressures become anisotropic due to the presence of the magnetic…

High Energy Astrophysical Phenomena · Physics 2015-10-14 D. Manreza Paret , A. Perez Martinez , J. E. Horvath

On the basis of theoretical evolutionary expectations, we develop a Galactic model reproducing star counts and synthetic color-magnitude diagrams of field stars, which include the white dwarf (WD) population. In this way we are able to…

Astrophysics · Physics 2007-05-23 M. Cignoni , V. Castellani , S. Degl'Innocenti , S. Petroni , P. G. Prada Moroni

Context: The astrophysical gravitational wave background (AGWB) is a stochastic gravitational wave (GW) signal that is emitted by different populations of inspiralling binary systems containing compact objects throughout the Universe. In…

High Energy Astrophysical Phenomena · Physics 2024-10-16 Sophie Hofman , Gijs Nelemans