A cluster brimming with millions of stars glistens like an iridescent opal in this image from NASA's Spitzer Space Telescope. Called Omega Centauri, the sparkling orb of stars is like a miniature galaxy. It is the biggest and brightest of the 150 or so similar objects, called globular clusters, that orbit around the outside of our Milky Way galaxy. Stargazers at southern latitudes can spot the stellar gem with the naked eye in the constellation Centaurus. Globular clusters are some of the oldest objects in our universe. Their stars are over 12 billion years old, and, in most cases, formed all at once when the universe was just a toddler. Omega Centauri is unusual in that its stars are of different ages and possess varying levels of metals, or elements heavier than boron. Astronomers say this points to a different origin for Omega Centauri than other globular clusters: they think it might be the core of a dwarf galaxy that was ripped apart and absorbed by our Milky Way long ago. In this new view of Omega Centauri, Spitzer's infrared observations have been combined with visible-light data from the National Science Foundation's Blanco 4-meter telescope at Cerro Tololo Inter-American Observatory in Chile. Visible-light data with a wavelength of .55 microns is colored blue, 3.6-micron infrared light captured by Spitzer's infrared array camera is colored green and 24-micron infrared light taken by Spitzer's multiband imaging photometer is colored red. Where green and red overlap, the color yellow appears. Thus, the yellow and red dots are stars revealed by Spitzer. These stars, called red giants, are more evolved, larger and dustier. The stars that appear blue were spotted in both visible and 3.6-micron-, or near-, infrared light. They are less evolved, like our own sun. Some of the red spots in the picture are distant galaxies beyond our own.

A bunch of useless individuals stars Generally known as “spider pulsars,” they obliterate companion stars inside their attain. Info from NASA’s Chandra X-ray Observatory Subordinate Spherical block Omega Centauri helps astronomers perceive how these spidery pulsars prey on their stellar companions.

a Pulsar It’s the dense, rotating core that continues to be after a large star collapses in on itself to type a star Neutron star. Quick-spinning neutron stars can produce beams of… radiation. Like a rotating lighthouse beam, a radiant could be noticed as a strong, pulsating supply of radiation, or a pulsar. Some pulsars orbit tens to tons of of occasions per second, and these are referred to as millisecond pulsars.

Spider pulsars are a particular class of millisecond pulsars, which get their identify from the injury they inflict on small companion stars in orbit round them. By way of winds of energetic particles streaming from spider pulsars, the outer layers of the pulsar’s companion stars are systematically stripped away.

Astronomers lately found 18 pulsars in Omega Centauri — positioned about 17,700 light-years from Earth — utilizing the Parkes and Meerkat radio telescopes. Then a pair of astronomers from the College of Alberta in Canada checked out Chandra’s information for Omega Centauri to see if any of the millisecond pulsars would erupt. X ray.

They discovered 11 millisecond X-ray-emitting pulsars, 5 of which have been spider pulsars centered close to the middle of Omega Centauri. The researchers then mixed the Omega Centauri information with Chandra observations of 26 spider pulsars in 12 different globular clusters.

There are two kinds of spider pulsars based mostly on the dimensions of the star being destroyed. Redback pulsars destroy companion stars that weigh between one-tenth and one-half the mass of the Solar. In the meantime, black widow pulsars destroy companion stars lower than 5% of the Solar’s mass.

The crew discovered a transparent distinction between the 2 courses of spider pulsars, with crimson stars being brighter in X-rays than black stars, confirming earlier work. The crew is the primary to point out that there’s a normal relationship between X-ray brightness and the mass accompanying spider pulsars, the place pulsars that produce extra X-rays are paired with extra large companions. This offers clear proof that the mass of the pulsars accompanying the spider impacts the X-ray dose acquired by the star.

The X-rays found by Chandra are considered generated primarily when winds of particles flowing away from pulsars collide with winds of matter blowing away from companion stars and produce Shock wavesmuch like these produced by supersonic plane.

Spider pulsars are sometimes separated from their companions by solely about one to 14 occasions the gap between the Earth and the Moon. This proximity, in cosmological phrases, causes energetic particles from pulsars to be significantly dangerous to their companion stars.

This result’s in line with theoretical fashions developed by scientists. As a result of extra large stars produce denser winds of particles, there’s a stronger shock — producing brighter X-rays — when their winds collide with particles coming from the pulsar. The proximity of companion stars to pulsars signifies that X-rays may cause important injury to stars, together with pulsar winds.

Chandra’s sharp X-ray imaginative and prescient is essential for learning millisecond pulsars in globular clusters as a result of they usually include giant numbers of X-ray sources in a small a part of the sky, making it tough to differentiate the sources from one another. Most of the millisecond pulsars in Omega Centauri produce other, unrelated X-ray sources positioned just a few arcseconds away. (An arcsecond is the obvious measurement of a coin seen at a distance of two.5 miles.)

The paper describing these outcomes might be revealed within the December difficulty of the Month-to-month Notices of the Royal Astronomical Society, and the preliminary model of the accepted paper might be Available online. The authors of this paper are Jiaqi (Jake) Zhao and Craig Heineke, each from the College of Alberta in Canada.

NASA’s Marshall Area Flight Middle manages the Chandra program. The Smithsonian Astrophysical Observatory’s Chandra X-ray Middle controls science operations from Cambridge, Massachusetts, and flight operations from Burlington, Massachusetts.

Read more from NASA’s Chandra X-ray Observatory.

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