Sentences with phrase «many planetary nebulae»

At that point, it will partly collapse, blow its outer shells of plasmatic gas into space, turn into a white dwarf, and begin to form a planetary nebula in its surroundings.

«New method to estimate more accurate distances between planetary nebulae and the Earth: Astronomers develop a new method to estimate more accurate distances between planetary nebulae and the Earth.»

This is a false color image of the planetary nebula NGC 6778.

With this technique, «planetary nebulae» finally get a more meaningful physical presence.

Ours is the first scale to be able to estimate distances for all planetary nebulae.

Chemical calculations show that helium hydride should be visible in clouds around distant galaxies and supernovas, or even in modern planetary nebulas (shells of gas expelled by aged, sunlike stars).

«NGC6778,» adds another of the authors, Hektor Monteiro, of the University fo Itajubá, Brazil, «is one of the planetary nebulae with the brightest recombination lines.

Ghostly and beautiful planetary nebulae» have nothing to do with planets but acquired this name because these glowing spheres of ionized gas resembled planets to early observers.

More accurate distances between the most common type of «planetary nebulae» and the Earth can be estimated simply with three sets of data: firstly, the size of the object on the sky taken from the latest high resolution surveys; secondly, an accurate measurement of how bright the object is in the red hydrogen - alpha emission line; and thirdly, an estimate of the dimming toward the nebula caused by so called interstellar - reddening.

«To do this,» explains Antonio Cabrera Lavers, head of astronomy at the GTC and one of the authors of the paper, «we have used for the first time the blue tunable filter of OSIRIS to take a deep image centred on the emission from the recombination lines of one of the oxygen ions in the planetary nebula 6778.»

«In the past, the old distance scales worked fairly well for small planetary nebulae but got systematically worse for the larger nebulae.

As big planetary nebulae are the most common, we will use our new scale in making an unbiased census of planetary nebulae in the Milky Way, which will then help answer some important research questions.»

That phase is called the proto - planetary nebula, and is so short that only a few of these objects are known.

Dr David Frew, Professor Quentin Parker and Dr Ivan Bojicic, based on a culmination of ten years of research work, developed a new method for measuring more accurate distances between «planetary nebulae» and the Earth.

To try to corroborate this theory, an image of the emission of a planetary nebula in the recombination lines of oxygen has been obtained with the GTC.

Very soon, perhaps in the next millennium or two, the star you can see in the center will shed those last bits of gas on top of it, exposing it fully to space, and the weird lobes of material will glow far more brightly, becoming a planetary nebula proper.

Most planetary nebulae are only a light year or so across, so this is a fantastically vast and gossamer structure.

«The first image of a new gaseous component in a planetary nebula.»

This is combined with the use of the authors» own robust techniques to effectively remove «doppelgangers» and mimics that have seriously contaminated previous planetary nebulae catalogues, which added considerable scatter to previous statistical distance scales.

Over the next thousand years the nebula is expected to evolve into a fully - fledged planetary nebula.

«During the past few years our group,» says David Jones, an astrophysicist at the IAC and another of the authors on the paper, «has discovered that the planetary nebulae with the biggest discrepancies in their abundances are usually associated with binary central stars which have been through a phase with a common envelope, that is to say the process of expansion of the more massive of the two stars has meant that the other star is orbiting within its outer atmosphere, and the viscosity has brought the stars very close to one another.

Based on a culmination of ten years of research work, the new method to estimate more accurate distances between planetary nebulae and the Earth developed by HKU astronomers promises a new era in scientists» ability to study and understand the fascinating if brief period in the final stages of the lives of low - and mid-mass stars.

So oddly, planets do have something to do with planetary nebulae.

After shining for many millions of years, stars end their lives, mainly, in two ways: very high mass stars die very violently as supernovae, while low mass stars end as planetary nebulae.

While globular clusters are billions of years old, the planetary nebula phase of a star's life only lasts for a few thousand years, so it's exceedingly rare to find them in globulars.

The first author of this research Dr David Frew, Research Assistant Professor, Department of Physics said: «measuring distances to Galactic «planetary nebulae» has been an intractable problem for many decades, because of the extremely diverse nature of both the nebulae themselves and their central stars.

Planetary nebulae, which got their name after being misidentified by early astronomers, are formed when an ageing star weighing up to eight times the mass of the sun ejects its outer layers as clouds of luminous gas (see Why stars go out in a blaze of glory).

IT LOOKS like a soap bubble or perhaps even a camera fault, but the image at right is a newly discovered planetary nebula.

This is because pockets of gas rich in heavy elements would be created if a comet in the outer regions of a solar system got vaporised by a dying star in its red giant phase or by the expanding planetary nebula that follows it (arxiv.org/abs/1001.4513).

That's according to a new explanation of the behaviour of planetary nebulae — bubbles of gas sloughed off by dying stars (pictured).

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

For this shot of the Ant Nebula, Schmidt started with typical Hubble data sets and combined them to achieve these colors, while also adjusting the color balance and sharpening the details to create an original view of the symmetrical planetary nebula, the remains of a star that blew itself to pieces.

[5] Since the discovery of Pease 1, only three other globular clusters have been found to host planetary nebulae: Messier 22, NGC 6441, and Palomar 6.

As well as this black hole, Messier 15 is known to house a planetary nebula, Pease 1 [4]-- and it was the first globular known to contain one of these objects [5].

By studying the jets from pre-planetary and planetary nebulae, Blackman and Lucchini were able to connect the energy and momentum involved in the accretion process with that in the jets; the process of accretion is what in effect provides the fuel for these jets.

In planetary nebulae, thought to be the evolved stage of pre-planetary nebula, the core is exposed and the hotter radiation it emits ionises the gas in the now weaker jets, which in turn glow.

Astronomers know that while large stars can end their lives as violently cataclysmic supernovae, smaller stars end up as planetary nebulae — colourful, glowing clouds of dust and gas.

«Pre-planetary» and «planetary» nebulae are different in the nature of the light they produce; pre-planetary nebulae reflect light, whereas mature planetary nebulae shine through ionisation (where atoms lose or gain electrons).

Astronomers were thrilled when they first saw the Hubble images of the planetary nebulas ngc 7027 and crl 2688, also known as the Egg nebula.

Soon it collides with the slower, cooler gas ahead of it, piling it up into a bright, dense cloud called a planetary nebula.

Its ultraviolet light detectors will reveal the composition of interstellar gas, the cores of galaxies and quasars, the outer atmospheres of cool stars and planets, planetary nebulas, and supernovas.

There are more than a thousand known planetary nebulae, and few have the simple, spherical shape that would be expected from a solitary star expelling its outer layers in dying gasps.

Hubble observations over the past two decades have revealed an enormous complexity and diversity of structure in planetary nebulae.

For decades, astronomers have suspected that planetary nebulae — dazzlingly colorful shrouds of gas cast off by dying stars — owe their weird but often symmetrical shapes to the sculpting magnetic forces of two stars orbiting each other at the nebula's center.

The model we propose can help explain the presence of bipolar planetary nebulae, the presence of knotty jet - like structures in many of these objects, and even multipolar planetary nebulae.

A planetary nebula is an expanding shell of glowing gas expelled by a star late in its life.

«We want to identify the process that causes these amazing transformations from a puffed - up red giant to a beautiful, glowing planetary nebula,» Sahai said.

The astronomers looked at 130 planetary nebulae in the Milky Way's central bulge.

The astronomers suggest that the orderly behaviour of the planetary nebulae could have been caused by the presence of strong magnetic fields as the bulge formed.

The final stages of life for a star like our Sun result in the star blowing its outer layers out into the surrounding space, forming objects known as planetary nebulae in a wide range of beautiful and striking shapes.