Results 31 to 40 of about 25,195 (313)

White Dwarfs in Wide Binaries: The Strong Effects of Stellar Evolution and Mass Loss

open access: yesThe Astrophysical Journal
We examine the statistics of main-sequence/main-sequence, main-sequence/white-dwarf, and white-dwarf/white-dwarf wide binaries at 10 ^2.5 –10 ^4 au separations in Gaia data.
Hsiang-Chih Hwang, Nadia L. Zakamska
doaj   +1 more source

A consistency test of white dwarf and main sequence ages: NGC 6791

open access: yesEPJ Web of Conferences, 2013
NGC 6791 is an open cluster that it is so close to us that can be imaged down to very faint luminosities. The main sequence turn-off age (∼8 Gyr) and the age derived from the cut-off of the white dwarf luminosity function (∼6 Gyr) were found to be ...
Córsico A.H.   +5 more
doaj   +1 more source

The Highly Accurate Relation Between the Radius and Mass of the White Dwarf Star From Zero to Finite Temperature

open access: yesFrontiers in Astronomy and Space Sciences, 2022
In this research, first considering the electron–electron interaction in the high-density Fermi electron gas at T = 0 K, this interaction causes the pressure 2/137 time less than the original value.
Ting-Hang Pei
doaj   +1 more source

Control of Covalent Bond Enables Efficient Magnetic Cooling

open access: yesAdvanced Materials, EarlyView.
Giant and reversible magnetocaloric effect (MCE) is achieved by tuning covalency through sub‐unit‐cell chemical engineering, establishing a novel design principle for effective hysteresis control in magnetocaloric materials. Abstract Magnetic cooling, harnessing the temperature change in matter when exposed to a magnetic field, presents an energy ...
Xin Tang   +16 more
wiley   +1 more source

Features of the mass transfer in magnetic cataclysmic variables with fast-rotating white dwarfs

open access: yesEPJ Web of Conferences, 2014
The flow structure in magnetic cataclysmic variables was investigated taking into account the effects of strong magnetic field and fast rotation of the white dwarf. We modeled the AE Aqr system as a unique object that has the rotation period of the white
Isakova Polina   +2 more
doaj   +1 more source

The Vegan Villain Sets Out to The End of Summer: Functionalized Coatings as Biohybrid UV‐Sensors

open access: yesAdvanced Materials Interfaces, EarlyView.
This study introduces biohybrid coatings incorporating E. coli biomass expressing photoconvertible fluorescent proteins as UV‐A responsive elements. Upon irradiation at 400 nm, the coatings exhibit an irreversible fluorescence shift from green to red within 15 min. Notably, the photoconversion capability is retained after >1 year of storage.
Amelie Skopp   +3 more
wiley   +1 more source

Magnetism in white Dwarfs [PDF]

open access: yesSymposium - International Astronomical Union, 1971
Searches have been made for the normal and quadratic Zeeman effect and broad-band circular polarization in white dwarf stars. A positive effect has been found in Grw + 70°8247 whose continuum shows both linear and circular polarization.
J. D. Landstreet, J. R. P. Angel
openaire   +1 more source

Circularly Polarized Structural Color Pigments Tunable Across the Full Visible Spectrum

open access: yesAdvanced Optical Materials, EarlyView.
By infusing black dye into spherical shells of polymerized cholesteric liquid crystal, blue, green and red omnidirectional retroreflectors of circularly polarized structural color are achieved. They can be laid out on arbitrary surfaces without any need for index matching binder to define graphical information for robots and Augmented Reality devices ...
Deniz Işınsu Avşar   +1 more
wiley   +1 more source

Studying the Radiation of a White Dwarf Star Falling onto a Black Hole

open access: yesThe Astrophysical Journal
We investigate electromagnetic and gravitational radiation generated during the process of the tidal stripping of a white dwarf star circulating a black hole.
Marek Nikołajuk   +3 more
doaj   +1 more source

Testing White Dwarf Age Estimates Using Wide Double White Dwarf Binaries from Gaia EDR3

open access: yesThe Astrophysical Journal, 2022
White dwarf (WD) stars evolve simply and predictably, making them reliable age indicators. However, self-consistent validation of the methods for determining WD total ages has yet to be widely performed.
Tyler M. Heintz   +6 more
doaj   +1 more source

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