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Big Gulp: Flaring Galaxy Marks the Messy Demise of a Star in a Supermassive Black Hole

A close look at a distant cataclysm indicates that the black hole’s victim was a red giant star

Once in a while, a supermassive black hole gets a sumptuous treat. A passing star wanders too close and gets caught in the black hole’s gravitational pull, like a fly trapped in a spider’s web. The star then becomes an easy meal for the black hole, which tears its prey to bits and ingests a good portion of it.

Astronomers have witnessed several such disruptions before in distant galaxies, but usually only toward the end of the process. (These feedings are far too rare, however, to have been witnessed in our own Milky Way anytime in recent human history; they occur only once every 10,000 years or so per galaxy.) Now researchers have documented a black hole’s feasting in such detail that they were able to infer its size as well as the type of star that fell prey to its gluttony.

Astronomers cannot peer inside a black hole itself; beyond the event horizon, a black hole’s point of no return, even light cannot escape into the outside world. But material falling into a black hole gives off intense flares of radiation as it compresses and heats up outside the event horizon.

Suvi Gezari, an astronomer at Johns Hopkins University, and her colleagues used a number of different telescopes to track the outburst from a supermassive black hole in a galaxy more than two billion light-years away as the black hole consumed a star that ventured too close.

“While there has been evidence of these types of flares before, there’s never been enough information to say what kind of star fell victim to the black hole, and what was the mass of the black hole that destroyed the star,” Gezari says. She and her colleagues published their findings online May 2 in Nature.

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Star Factory Blazes Bright in Stunning New Photo

Huge, glowing clouds of gas and dust that will one day collapse to form massive new stars take center stage in a new photo from a European space telescope.

The image, snapped by the European Space Agency’s Herschel space observatory, shows Cygnus-X, an extremely active star-forming region about 4,500 light-years from Earth in the constellation Cygnus (The Swan).

The Herschel observatory sees extremely well in far-infrared wavelengths, allowing scientists to seek out and study stellar nurseries like Cygnus-X — places where dense clumps of gas have been gently heated by stars.

In the new photo, bright white areas highlight areas where large stars have recently formed out of such clouds, researchers said. These clumps are particularly evident in the right-hand side of the image, which shows a chaotic network of filaments.

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What’s the Origin of Exploding Stars? Two Right Answers

Astronomers have long had two competing explanations for the origin of exploding stars called Type Ia supernovas. A new study, to be published in the Astrophysical Journal, suggests both explanations might be at work.

Type Ia supernovas were used to discover dark energy and are used to measure the universe. They’re so bright we can see them from across the cosmos, and each acts like a “standard candle,” giving off a known luminosity. But astronomers don’t know what star systems make Type Ia supernovas — what processes lead to the explosions.

“Previous studies have produced conflicting results. The conflict disappears if both types of explosion are happening,” explained Smithsonian astronomer Ryan Foley, with the Harvard-Smithsonian Center for Astrophysics.

Type Ia supernovae are known to originate from white dwarfs, the aged, dense cores of dead stars.

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Giant HII Clouds of NGC 2403

Copyright: Robert Gendler

Distance: 10.4 Million Light Years

NGC 2403 is a luminous member of the M81 group of galaxies. Similar in morphology to M33, NGC 2403 is noted for its exceptionally bright HII regions and high rate of star formation.

A subset of its HII regions are so exceptionally bright that each are comparable to the most massive HII regions in our local group of galaxies, the 30 Doradus complex within the Large Magellenic cloud and NGC 604 in M33. These immense and exceptionally luminous emission clouds are called Giant HII regions.

Dark Doodad

Image Copyright: Yuriy Toropin

The Dark Doodad molecular cloud could be seen here in wide field gliding over Musca constellation, surrounded by other objects, including Cederblad 110 and Ced 111 in Chameleon, dark cloud seen at the bottom part of the shot.

In the Center of the Omega Nebula

Image Credit: NASA, H. Ford (JHU), G. Illingworth (UCSC/LO), M.Clampin (STScI), G. Hartig (STScI), ACS Science Team, and ESA

In the depths of the dark clouds of dust and molecular gas known as the Omega Nebula, stars continue to form.

The above image from the Hubble Space Telescope’s Advanced Camera for Surveys shows exquisite detail in the famous star-forming region.

The dark dust filaments that lace the center of Omega Nebula were created in the atmospheres of cool giant stars and in the debris from supernova explosions. The red and blue hues arise from glowing gas heated by the radiation of massive nearby stars.

The points of light are the young stars themselves, some brighter than 100 Suns. Dark globules mark even younger systems, clouds of gas and dust just now condensing to form stars and planets. The Omega Nebula lies about 5000 light years away toward the constellation of Sagittarius. The region shown spans about 3000 times the diameter of our Solar System.

NGC 225 & vdB4: Sailboat Cluster

by David Churchill

Data Imaged remotely over 4 nights (Oct 27, 28, 30, & 31, 2011). Rich region. with Vdb4 as the main bright object. Two Open clusters NGC 225 just below center, and CA Berk3 to the right. Also several dark nebulae - LDN 1291 is above center, LDN 1294 is at the edge above center, & LDN 1300 is at the bottom.

Dust in Orion

This image of the region surrounding the reflection nebula Messier 78, just to the north of Orion’s belt, shows clouds of cosmic dust threaded through the nebula like a string of pearls.

The submillimetre-wavelength observations, made with the Atacama Pathfinder Experiment (APEX) telescope and shown here in orange, use the heat glow of interstellar dust grains to show astronomers where new stars are being formed. They are overlaid on a view of the region in visible light.

Solar System’s Death Glimpsed in White Dwarf Stars

Image: Three panels illustrate the death sequence of a planetary system. Four terrestrial planets orbit a sun-like star (top); the host star turns into a red giant and mixes up planetary orbits, causing them to collide (middle); dusty debris and asteroid-like objects are all that remains around the star, now a white dwarf (bottom). (Copyright of Mark A. Garlick/University of Warwick)

Four dead planetary systems, each lit by the burned-out core of a star that once resembled the sun, provide a harrowing forecast for Earth’s eventual demise.

Astronomers used the space-based Hubble telescope to probe the chemical signatures of dusty disks encircling the four star systems. In each they found a surprising abundance of elements that make up about 93 percent of Earth’s mass.

“What we are seeing today in these white dwarfs several hundred light years away could well be a snapshot of the very distant future of the Earth,” said Boris Gänsicke, an astrophysicist at the University of Warwick, in a press release.

Gänsicke and his team’s research on the white dwarfs, released May 1 on arXiv, suggests that the stars’ death throes pulverized the nearest planets, leaving only chunks of their cores. The team’s study is accepted for publication in the Monthly Notices of the Royal Astronomical Society.

The sun is about 4.57 billion years old and should survive another 5 billion years or so in its current state. After that it will run low on its hydrogen fuel, the fusion of which presently pushes away gas that would otherwise gather at its core. As the gas accumulates, rising pressure will fuse heavier helium atoms into carbon, drastically increasing the star’s core temperature.

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NGC 7635: Bubble in a Cosmic Sea

Credit: Digitized Sky Survey, ESA/ESO/NASA FITS Liberator

Color Composite: Davide De Martin (Skyfactory)

Seemingly adrift in a cosmic sea of stars and glowing gas, the delicate, floating apparition near the center (next to a blue tinted star) of this widefield view is cataloged as NGC 7635 - The Bubble Nebula.

A mere 10 light-years wide, the tiny Bubble Nebula and the larger complex of interstellar gas and dust clouds are found about 11,000 light-years distant, straddling the boundary between the parental constellations Cepheus and Cassiopeia. Also included in the breathtaking vista is open star cluster M52 (upper left), some 5,000 light-years away.

The digital color picture is based on photographic plates taken at the Palomar Observatory between 1992 and 1997. This cropped version spans about 2.7 degrees on the sky corresponding to a width of just over 500 light-years at the estimated distance of the Bubble Nebula.

IC 405: Flaming Star Nebula

Image: Marc Jousset

Description: Robert Gendler

First discovered in 1892, the nebula complex IC 405 was eloquently described by Max Wolf in 1903 as “a burning body from which several enormous curved flames seem to break out like gigantic prominences”. Eventually “The Flaming Star Nebula” became adopted as the popular name for IC 405.

Center of Centaurus A

A fantastic jumble of young blue star clusters, gigantic glowing gas clouds, and imposing dark dust lanes surrounds the central region of the active galaxy Centaurus A.

This mosaic of Hubble Space Telescope images taken in blue, green, and red light has been processed to present a natural color picture of this cosmic maelstrom. Infrared images from the Hubble have also shown that hidden at the center of this activity are what seem to be disks of matter spiraling into a black hole with a billion times the mass of the Sun.

Has Our Galaxy’s Dark Matter Gone Missing?

If a new study is true, then the search for dark matter just got a lot weirder. Our little corner of the Milky Way contains no observable concentration of the mysterious stuff whose gravity binds the galaxy, claims one team of astronomers.

That finding would present a major problem for models of how galaxies form and may undermine the whole notion of dark matter, the researchers claim. But some scientists doubt the reliability of the team’s method for measuring the elusive substance.

“This is not just some piddling little detail,” says Frederic Hessman, an astronomer at the University of Göttingen in Germany who was not involved in the work. “If this is right, it turns everything totally upside-down.” But that’s a big if, says Julio Navarro, an astrophysicist at the University of Victoria in Canada: “The argument is provocative, but it remains inconclusive, in my opinion.”

According to standard cosmology, we should be swimming in dark matter. Measurements of the afterglow of the big bang—the so-called cosmic microwave background—and of the distribution of the galaxies suggest that 85% of all matter in the universe is dark matter. What’s more, decades of astronomical observations show that the stars within galaxies swirl about faster than they could if only the gravity of the others stars were holding them in. In fact, the speed with which the sun goes around the center of our galaxy suggests that dark matter ought to be about as abundant as ordinary matter at our distance from the galactic center, about 27,000 light-years.

But that’s not what Christian Moni Bidin, an astronomer at the University of Concepción in Chile, and colleagues find. Using data gathered with several telescopes, they studied old stars called red giants in a cylindrical region a couple of light-years wide and extending 13,000 light-years above the plane of the galaxy.

Treating the stars a bit like atoms in a gas, researchers assumed that they were trapped in the gravitational “well” of the galaxy. So by studying distributions of the stars’ speeds in three dimensions, they could deduce the well’s shape and hence the total distribution of mass from both dark and ordinary matter along the cylinder. Subtracting the distribution of ordinary matter as determined from star counts would then reveal the distribution of dark matter.

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Fox Fur, a Unicorn, and a Christmas Tree

Image Credit: Rolf Geissinger

What do the following things have in common: a cone, the fur of a fox, and a Christmas tree? Answer: they all occur in the constellation of the unicorn (Monoceros).

Pictured above as a star forming region cataloged as NGC 2264, the complex jumble of cosmic gas and dust is about 2,700 light-years distant and mixes reddish emission nebulae excited by energetic light from newborn stars with dark interstellar dust clouds.