One of the fastest moving stars ever seen has been discovered with NASA's Chandra X-ray Observatory. This cosmic cannonball is challenging theories to explain its blistering speed.
Astronomers used Chandra to observe a neutron star, known as RX J0822-4300, over a period of about five years. During that span, three Chandra observations clearly show the neutron star moving away from the center of the Puppis A supernova remnant. This remnant is the stellar debris field created during the same explosion in which the neutron star was formed about 3700 years ago.
By combining how far it has moved across the sky with its distance from Earth, astronomers determined the neutron star is moving at over 3 million miles per hour.
Astronomers have discovered white dwarf stars with pure carbon atmospheres. The discovery could offer a unique view into the hearts of dying stars.
These stars possibly evolved in a sequence astronomers didn't know before. They may have evolved from stars that are not quite massive enough to explode as supernovae but are just on the borderline. All but the most massive two or three percent of stars eventually die as white dwarfs rather than explode as supernovae.
When a star burns helium, it leaves "ashes" of carbon and oxygen. When its nuclear fuel is exhausted, the star then dies as a white dwarf, which is an extremely dense object that packs the mass of our sun into an object about the size of Earth.
NASA's Hubble Space Telescope has probed the bright core of Comet 17P/Holmes, which, to the delight of sky watchers, mysteriously brightened by nearly a millionfold in a 24-hour period beginning Oct. 23, 2007.
Comet 17P/Holmes is a periodic comet in our solar system.
On November 4, 2007, Comet 17P/Holmes was 1.62 Astronomical Units from the Earth, and 2.48 Astronomical Units from the Sun. Constellation: Perseus
Astronomers used Hubble's powerful resolution to study Comet Holmes' core for clues about how the comet brightened. The orbiting observatory's Wide Field Planetary Camera 2 (WFPC2) monitored the comet for several days, snapping images on Oct. 29, Oct. 31, and Nov. 4.
Rocky terrestrial planets, perhaps like Earth, Mars or Venus, appear to be forming or to have recently formed around a star in the Pleiades ("seven sisters") star cluster, the result of "monster collisions" of planets or planetary embryos.
Astronomers using the Gemini Observatory in Hawaii and the Spitzer Space Telescope report their findings in an upcoming issue of the Astrophysical Journal, the premier journal in astronomy.
Known until now as a simple number in a catalogue, NGC 134, the 'Island in the Universe' that was observed by the European Commissioner for Science and Research Janez Potočnik on a visit to ESO's Very Large Telescope at Paranal is replete with remarkable attributes, and the VLT has clapped its eyes on them.
Just like our own Galaxy, NGC 134 is a barred spiral with its spiral arms loosely wrapped around a bright, bar-shaped central region.
One feature that stands out is its warped disc. While a galaxy's disc is often pictured as a flat structure of gas and stars surrounding the galaxy's centre, a warped disc is a structure that, when viewed sideways, resembles a bent record album left out too long in the burning Sun.
Scientists using the largest cosmic ray observatory in the world, the Pierre Auger Observatory in Argentina, have made an important discovery about the highest-energy cosmic rays that hit the Earth - and the discovery leads back to supermassive black holes.
In Science, the Pierre Auger Collaboration announces that Active Galactic Nuclei - thought to be powered by supermassive black holes that devour large amounts of matter - are the most likely candidate for the source of the highest-energy cosmic rays that hit Earth.
The scientists found that the sources of the highest-energy particles are not distributed uniformly across the sky.
When the stars are shining above the atmosphere, they give off radiation across a wide spread of wavelengths. As Earth rotates, the star appears to sink down. When that happens, the atmosphere acts as a filter, blocking out certain wavelengths of the star’s radiation. While nice to see with your girlfriend, of importance to astronomers is that the blocked wavelengths are representative of the molecules and atoms in the planet’s atmosphere.
It's known as stellar occultation. Jean-Loup Bertaux, Service d'Aeronomie du CNRS, France was the first to suggest its use on an ESA mission. It works by watching stars from space, while they drop behind the atmosphere of a planet under investigation, before disappearing from view below the planet’s horizon.
Astronomers at the Harvard-Smithsonian Center for Astrophysics (CfA) have found that a supernova discovered last year was caused by two colliding white dwarf stars. The white dwarfs were siblings orbiting each other. They slowly spiraled inward until they merged, touching off a titanic explosion. CfA observations show the strongest evidence yet of what was, until now, a purely theoretical mechanism for creating a supernova.
"This finding shows that nature may be richer than we suspected, with more than one way to make a white dwarf explode," said Harvard graduate student and first author Malcolm Hicken.
Supermassive black holes can produce powerful winds that shape a galaxy and determine their own growth, confirms a group of scientists from Rochester Institute of Technology.
The RIT team has, for the first time, observed the vertical launch of rotating winds from glowing disks of gas, known as accretion disks, surrounding supermassive black holes in the centers of galaxies. The findings are reported in the Nov. 1 issue of Nature.
Gas flowing into a supermassive black hole first accumulates in a rapidly spinning accretion disk, which forms the engine of a quasar, a type of active galactic nucleus found in some galaxies and an extremely powerful source of radiation.
The "dark matter" that comprises a still-undetected one-quarter of the universe is not a uniform cosmic fog, says a University of California, Berkeley, astrophysicist, but instead forms dense clumps that move about like dust motes dancing in a shaft of light.
In a paper from Physical Review D, Chung-Pei Ma, an associate professor of astronomy at UC Berkeley, and Edmund Bertschinger of the Massachusetts Institute of Technology (MIT), prove that the motion of dark matter clumps can be modeled in a way similar to the Brownian motion of air-borne dust or pollen.
Their findings should provide astrophysicists with a new way to calculate the evolution of this ghost universe of dark matter and reconcile it with the observable universe, Ma said.