Sentences with phrase «for white dwarf»

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.

But the Spitzer data for the white dwarf PG 0010 +280 did not fit well with models for asteroid disks, leading the team to look at other possibilities.

The new method should already become viable for white dwarf systems in five years» time as the JWST goes online.

«Surface helium detonation spells end for white dwarf.»

It was named in honor of Indian - American physicist Subrahmanyan Chandrasekhar who is known for determining the mass limit for white dwarf stars to become neutron stars.

Other evidence for white dwarfs shredding asteroids comes from observations of the elements in white dwarfs.

A different set of spectral peculiarity symbols are used for white dwarfs than for other types of stars:

Luminosity class 0 or Ia + is used for hypergiants, class I for supergiants, class II for bright giants, class III for regular giants, class IV for sub-giants, class V for main - sequence stars, class sd (or VI) for sub-dwarfs, and class D (or VII) for white dwarfs.

The class D (for Degenerate) is the modern classification used for white dwarfs — low - mass stars that are no longer undergoing nuclear fusion and have shrunk to planetary size, slowly cooling down.

The sequence has been expanded with classes for other stars and star - like objects that do not fit in the classical system, such as class D for white dwarfs and classes S and C for carbon stars.

Not exact matches

One of the trailers for the kid's movie has been removed, as it shows two of the dwarves spying on Snow White as she undresses.

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.

For the first time, scientists using NASA's Hubble Space Telescope have witnessed a massive object with the makeup of a comet being ripped apart and scattered in the atmosphere of a white dwarf, the burned - out remains of a compact star.

These findings are evidence for a belt of comet - like bodies orbiting the white dwarf, similar to our solar system's Kuiper Belt.

Previous studies show that it takes about 68 days for the pulsar to orbit its white dwarf companion, meaning they share an uncommonly wide orbit.

The unseen movers are fast - moving white dwarf stars that could account for as much as one - third of the galaxy's dark matter.

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.

The event was what's known as a classical nova explosion, which occurs when a dense stellar corpse called a white dwarf steals enough material from an ordinary companion star for its gas to spontaneously ignite.

For the past two years, Winget and his colleagues at the University of Texas at Austin and Sandia National Laboratory in Albuquerque, New Mexico, have been creating searing plasmas that are, in effect, miniature versions of white dwarfs, ancient stars that have burned up all their nuclear fuel.

«We knew about these debris disks around white dwarfs for over twenty years, but have only now been able to obtain the first image of one of these disks,» says Mr Manser.

WHAT LIES WITHIN The inner structure of a white dwarf star (shown in this artist's impression) has been mapped for the first time — and it's more oxygen - rich than expected.

Cruelly, the dense white dwarf star could also be headed for a violent demise unlike anything we've ever seen.

In 2014, scientists found another reason to rejoice in your genes» deterioration: White dwarf stars, like the remnant that will remain at the end of the sun's life, eat rocky planets like Earth for their last meal.

But it also monitored white dwarf KIC 08626021, located 1,375 light - years away in the constellation Cygnus, for 23 months.

NEWSPAPER obituaries of Subrahmanyan Chandrasekhar, who died last month aged 84, all highlighted the single achievement for which he will be best remembered — his work on white dwarf stars.

«If you park a planet in a habitable zone around a white dwarf, it will stay there for a very, very long time — potentially enough time for life to...

Professor Mould and his PhD student Syed Uddin at the Swinburne Centre for Astrophysics and Supercomputing and the ARC Centre of Excellence for All - sky Astrophysics (CAASTRO) assumed that these supernova explosions happen when a white dwarf reaches a critical mass or after colliding with other stars to «tip it over the edge».

Neither study searched for the stars responsible for so - called type Ia supernovae, which are explosions of white dwarf stars that have grown overweight by feasting on material from a companion star.

Observations of the explosions of white dwarf stars in binary systems, so - called Type Ia supernovae, in the 1990s then led scientists to the conclusion that a third component, dark energy, made up 68 % of the cosmos, and is responsible for driving an acceleration in the expansion of the universe.

And even then, the planet would have to orbit a special kind of star, a white dwarf, for the CFCs to show up.

The standard path to type Ia supernovae, the study's authors wrote, should have produced 30 to 50 times the x-rays observed, indicating that accreting white dwarfs account for less than 5 percent of the explosions.

But thanks to a key prediction in general relativity, we have directly measured the mass of a white dwarf for the first time.

This is too small for normal stars or white dwarfs, but fine for neutron stars.

«In order for the asteroids to pass sufficiently close to the white dwarf to be shredded, then eaten, they must be perturbed from the asteroid belt — essentially pushed — by a massive object like a giant planet,» said Farihi.

Those remnants went into orbit around the white dwarf — much like the rings around Saturn, Zuckerman said — before eventually spiraling onto the star itself, bringing with them the building blocks for life.

With JWST, a few hours of integration time will be enough to detect Earth - like levels of water vapor, molecular oxygen, carbon dioxide and other generic biosignatures on planets orbiting a white dwarf; beyond that, observing the same planet for up to 1.7 days will be enough to detect the two CFCs in concentrations of 750 parts per trillion, or 10 times greater than on Earth.

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.

Because these planets are light years away, and because the reflected light is incredibly dim, the James Webb Space Telescope will only be able to do this for large planets that orbit red and white dwarfs — but still, it's incredibly exciting to think that we might be able to identify signs of life from all the way over here on our little blue marble.

As for the space diamond, ancient white dwarfs aren't uncommon in space, but they're incredibly difficult to find.

Zeta Doradus is a main sequence dwarf star of spectral and luminosity type F7 V but has been classed as white as F6 and as yellow as F9 (Lagrange et al, 2009, page 14 for HD 33262; Trilling et al, 2008, page 26; NASA Stars and Exoplanet Database; and SIMBAD).

Even for these more massive stars, however, if the residual mass in the core is less than 1.4 solar masses (the Chandrasekhar limit), the stellar remnant will become a white dwarf.

Scientists from a large international collaboration (Oxford, AWE, CEA, LULI, Observatoire de Paris, University of Michigan and University of York) have succeeded for the first time to generate a laboratory analogue of a strong shock that takes place when matter falls at very high speed on the surface of extremely dense stars called white dwarfs.

As white dwarfs age, they become cooler and fainter, becoming difficult even for sharp - eyed Hubble to detect.

In any case, LP40 - 365 is the first known white dwarf to have survived a (failed) Type Ia supernova, and as such it opens up some exciting prospects for future science.

Researchers using NASA's Hubble Space Telescope have observed, for the first time ever, an enormous object with the composition of a comet being shredded and scattered by a white dwarf, the burned - out husk of a massive star.

Its mass and diameter are consistent with the theoretical size for a carbon - core white dwarf, one that may have evolved from a 5.05 +0.374 / -0.276 Solar - mass, B - type main - sequence star about 124 + / - 5 million years ago, after 101 to 126 million years as a giant star (Liebert et al, 2005; and Ken Croswell, 2005).

Peering deep into the Milky Way's crowded central hub of stars, Hubble researchers have uncovered for the first time a population of ancient white dwarfs — smoldering remnants of once - vibrant stars that inhabited the core.

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).

UC Santa Barbara Astrophysicists are the first to identify two white dwarf stars in an eclipsing binary system, allowing for the first direct radius measurement of a rare white dwarf.

From the original description, the team knew they were looking for a nova eruption — an extremely powerful explosion, where a white dwarf is fed by hydrogen from a nearby star.