White dwarfs crystallize as they cool
نویسندگان
چکیده
منابع مشابه
Cool versus Ultracool White Dwarfs
A preliminary BV RIJHK analysis of the white dwarfs SSSPM J2231−7514 and SSSPM J2231−7515 is presented. Although both stars were reported to have Teff < 4000 K, the analysis here indicates Teff ≈ 4250 K for both SSSPM J2231−7514 and SSSPM J2231−7515. Given substantial scientific interest in the coolest extant degenerate stars, it is necessary to distinguish sub 4000 K objects from the bulk of c...
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Low-mass companions to high-mass stars are difficult to detect, which is partly why the binary fraction for high-mass stars is still poorly constrained. Low-mass companions can be detected more easily however, once high-mass stars turn into white dwarfs. These systems are also interesting as the progenitors of a variety of intensely studied interacting binary systems, like novae, CVs, symbiotic...
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We present a small data base of homogeneously derived photospheric element abundances of DZ white dwarfs and related objects. Our previous investigations are supplemented with the analysis of ultraviolet spectra for nine white dwarfs. Of particular interest is the detection of Lα absorption in van Maanen 2 and a determination of the effective temperature of this star. The new value is about 100...
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The standard explanation for the presence of photospheric metals in white dwarfs of spectral type DZ and related types is a combination of episodic accretion from the interstellar medium and diffusion of heavy elements downwards in the atmosphere on time scales of typically 106 years. Much of the empirical data on atmospheric parameters and element abundances available in the literature is base...
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A detailed analysis of the very cool white dwarfs SDSS 1337+00 and LHS 3250 is presented. Model atmosphere calculations with improved collision-induced absorptions by molecular hydrogen indicate that a pure hydrogen composition can be ruled out, and that the strong infrared absorption observed in these cool stars is better explained in terms of collisions of H 2 with neutral helium. It is shown...
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ژورنال
عنوان ژورنال: Physics Today
سال: 2019
ISSN: 0031-9228,1945-0699
DOI: 10.1063/pt.3.4156