Sentences with phrase «hot white dwarf»

David Aguilar, Harvard - Smithsonian Center for Astrophysics — larger «day» and «night» images At maximum brightness, Mira would light up a hypothetical planetary companion, but at its most dark, the giant star's small, hot white dwarf companion would become visible (more discussion with illustration).

The remnant of the star that is left is an intensely hot white dwarf with a surface temperature as high as 100 000K.

They are bright in the far ultraviolet, a trademark of a hot white dwarf.

Invisible dark matter may have started out as hot white dwarfs like this one in the middle of planetary nebula NGC 2440.

H1504 +65 is the hottest white dwarf on record — and the only known star lacking helium and hydrogen.

Hubble uncovered extremely faint and hot white dwarfs.

The extremely hot white dwarfs appear bluer relative to sun - like stars.

The team based its results on an analysis of 70 of the hottest white dwarfs detectable by Hubble in a small region of the bulge among tens of thousands of stars.

Not exact matches

A white dwarf is very hot when it is formed, but since it has no source of energy, it will gradually radiate away its energy and cool down.

«The gas which forms the major part of the insterstellar medium,» explains Jorge García Rojas, a researcher at the IAC who is the first author on the paper «can be observed because its atoms are ionized by the photons emitted by the hot stars embedded inside it (which can either very massive stars, or white dwarfs, which are also very hot).

The researchers found that relatively cool accretion discs around young stars, whose inner edges can be several times the size of the Sun, show the same behaviour as the hot, violent accretion discs around planet - sized white dwarfs, city - sized black holes and supermassive black holes as large as the entire Solar system, supporting the universality of accretion physics.

Creating so much oxygen takes a fiercer nuclear furnace than is needed for a carbon - rich mixture, so the stars that became these white dwarfs must have been hot and massive.

The diffuse cloud in this image, taken with the Carnegie Institution for Science's Swope telescope in Chile, is the shell of hot hydrogen gas ejected by a white dwarf star on March 11, 1437.

In their new study, the Leicester - led team assesses whether these laws are the same within the hot, dense conditions in the atmosphere of a dying white dwarf star as here on Earth.

The youngest white dwarfs are the hottest and emit strongly in the extreme ultraviolet, which corresponds to temperatures between 100 000 °C and about 1 million °C.

The spacecraft's telescopes are sensitive to radiation from the hot outer atmospheres of stars like the Sun and white dwarfs, formed when stars about the size of the Sun reach the end of their lives.

Finally, about 130 million years after the red giant phase, the sun will go through a final spasm and eject its outer layers into space, leaving behind a white dwarf: a hot, dense lump of carbon and oxygen no larger than Earth.

These eventually disperse and leave behind hot, compact objects known as white dwarfs.

If a white dwarf is massive enough to fuse the iron in its core, those iron atoms are incredibly hot and densely packed, squashed together like sweaty clowns stuck in a circus car.

As Vega is so much bigger and hotter than Sol, however, the star will exhaust its core hydrogen after only another 650 million years or so (for a total life of around a billion years) and turn into a red giant or Cepheid variable before puffing away its outer layers to reveal a remnant core as a white dwarf.

It may be only about 225 to 250 million years old (Liebert et al, 2005; and Ken Croswell, 2005), but being so much bigger and hotter than Sol, the star will exhaust its core hydrogen within only a billion years and turn into a red giant or Cepheid variable before puffing away its outer layers to reveal a remnant core as a white dwarf.

While now tiny compared to main sequence stars, white dwarf stars are actually intensely hot, but without the internal heat of fusion to keep them burning, they gradually cool and fade away.

While tiny compared to main sequence stars, white dwarf stars are actually intensely hot, but without the internal heat of fusion to keep them burning, they gradually cool and fade away.

Nominal luminosity class VII (and sometimes higher numerals) is now rarely used for white dwarf or «hot sub-dwarf» classes, since the temperature - letters of the main sequence and giant stars no longer apply to white dwarfs.

A planetary nebula is a phase of stellar evolution that the sun should experience several billion years from now, when it expands to become a red giant and then sheds most of its outer layers, leaving behind a hot core that contracts to form a dense white dwarf star.

When a star ages and the red giant phase of its life comes to an end, it starts to eject layers of gas from its surface leaving behind a hot and compact white dwarf.