Scientists Discovered a Black Hole Bonanza

Black Hole Bonanza

Researchers find 26 possible black holes in Andromeda, a galaxy near our own Black holes can't be seen directly But astronomers can detect material falling into them when they interfere with other stars

You're in no danger of falling in, but a large group of possible cosmic vacuum cleaners have just been identified.

Researchers have come upon 26 possible black holes in Andromeda, a galaxy near our own.

This is the largest number of possible black holes found in a galaxy outside the Milky Way, but that may be because of Andromeda's relative proximity to our galaxy. It's probably easiest for Earth-based scientists to find black holes outside the Milky Way there, said Robin Barnard of the Harvard-Smithsonian Center for Astrophysics in Cambridge, Massachusetts.

Combining this discovery with previous observations of nine other black hole candidates, scientists can say that Andromeda has a total of 35 possible black holes. The research is published in The Astrophysical Journal.

NASA's Chandra X-ray Observatory made more than 150 observations over the course of 13 years to identify these black hole candidates.

Seven of the new potential Andromeda black holes reside within 1,000 light years of the center of that galaxy. This supports earlier research showing that, near the center of Andromeda, there are an unusual number of X-ray sources.

Black holes can't be seen directly. But astronomers can detect material falling into them when they interfere with other stars.

A black hole is a dense region of space that has collapsed in on itself in such a way that nothing can escape it, not even light.

In a binary system of this nature, a black hole and a star orbit each other closely. Material from the star falls into the black hole and "as it spirals in, it gets hotter and hotter, and faster and faster, and eventually it gives off X-rays, so we see lots and lots of X-rays coming out of it," Barnard said.

The material as it has been swallowed gets incredibly hot, up to about 10 billion degrees. Because of the tremendous amount of energy released, some of the brightest objects in the universe are black holes.

It's hard for scientists to distinguish distant black holes from neutron stars, however.

When a star explodes in a supernova, its fiery death leaves behind either a neutron star or a black hole, which is a more extreme version of a neutron star.

If our own sun were a neutron star, it would be only about 10 kilometers, or 6.2 miles, across, Barnard said. By comparison, as a black hole our sun might be only 2 kilometers across. Black holes of the kind that scientists may have spotted in Andromeda have masses that are typically five to 10 times that of the sun.

Neutron stars have a surface, so falling material pounds onto it, Barnard said. Material rains down at enormous speeds, causing huge explosions and energy emissions.

Billions of years from now, the Milky Way and Andromeda galaxies will collide, marking the end of the galaxy as we know it.

How Stars Die : Surprising News : Read Inside

Scientists studied the sodium content of stars in the cluster known as NGC 6752.

The way that stars spend their last years is largely shaped by their sodium "diet," according to a surprising new study published on Wednesday.

The study could upend current theories about how some stars that are similar to our sun die and become the basic building blocks for the next generation of stars and planets.

According to existing stellar evolution models, sunlike stars—those that are similar in size and chemical composition to our sun—swell to become so-called red giants in their final stage of life, before losing their atmospheres in a spectacular bubble of gas and dust.

This fate awaits our own sun in 4 to 5 billion years, scientists say.

The final period in a sunlike star's life, when stars make their greatest contribution to the universe, is known as the asymptotic giant branch (AGB).

"They puff off all their outer layers of gas and dust, enriching and polluting the surrounding space," said Simon Campbell, an astronomer at Monash University in Australia and the co-author of the new study published in the journal Nature.

"This gas and dust gets recycled and goes into the formation of the next generation of stars, planets—and possibly even life."

But now astronomers have found that not all sunlike stars follow the same rules when it comes to the end of their life cycles, and that some can skip the AGB phase altogether.

Chemical Fingerprints

Campbell and his team studied a giant ball of stars known as NGC 6752, one of the sky's brightest globular clusters. The collection of about one million stars sits 13,000 light-years from Earth in the southern constellation Pavo.

Globular clusters are considered the perfect cosmic laboratories for studying stars and testing stellar computer models because they have so many stars, in all phases of life.

Campbell's team used the European Southern Observatory's Very Large Telescope in the Atacama Desert of Chile. The giant telescope was equipped with a spectrograph—a prism used to break starlight into its colors—which allowed the researchers to obtain the chemical fingerprints of 130 cluster stars at once.

The team immediately noticed that the cluster is home to both a first generation of stars, at least 10 billion years old, and a second generation that is billions of years younger—and that the two groups appeared to contain different amounts of sodium.

"It's a bit like using sodium as a chemical 'tag' to follow each population of stars," said Campbell.

By tracking the sodium levels, the researchers were able to identify which stars would undergo the AGB phase at the end of their lives.

"We suspected sodium might be a good 'tracer' because it cannot be altered by the stars themselves because they are too low mass, and not hot enough to create or burn sodium," Campbell said.

His team quickly realized that some members of the cluster didn't appear to follow accepted theories when it came to undergoing the final burn stages, or AGB, when they were dying. Some skipped this final burst of nuclear burning entirely.

All the AGB stars in the study were first-generation stars with low levels of sodium, while none of the higher-sodium second-generation stars had become AGB stars.

It turns out that up to 70 percent of the stars in the NGC 6752 cluster were not undergoing the final "nuclear burning and mass-loss phase so indicative of sunlike stars," said Campbell.

Stellar Mystery

Exactly why there are two broad groups of stars with starkly different sodium levels in globular clusters is still unknown, Campbell said, and is a hot topic in stellar research.

How the newfound breed of sodium-rich, sunlike stars ultimately die is still something of a mystery. Campbell suspects they may directly evolve into small-Earth-size white dwarf stars that gradually cool over many billions of years.

But he said that one thing's for sure: Existing computer models of how sunlike stars die will need to be adjusted.

The wild activity of our magnificent SUN

The Sun 

The solar maximum is nearly in full swing, and the solar system has been in a hullabaloo from the sun's activity.

As we've mentioned before, the solar maximum will have a few effects here on earth. You're probably most likely to notice interruptions to radio and navigation devices (so if you get lost, you can quite rightly tell people that it's the fault of a disaster). Generally, though, the effects are quite benign and, if you're lucky, you'll get to catch the most visually amazing phenomenon of which our sky is capable.

Meanwhile, NASA's Solar Dynamics Observatory (SDO) has been compiling some amazing images of solar activity. If you want to get a better idea of what's going on with the old treacle bun, have a click through the gallery below to see what a solar maximum actually entails.

Galaxy's Ring of Fire by NASA

Galaxy's Ring of Fire

How many rings do you see in this new image of the galaxy Messier 94, also known as NGC 4736? While at first glance one might see a number of them, astronomers believe there is just one. This image was captured in infrared light by NASA's Spitzer Space Telescope. Image credit: NASA/JPL-Caltech

Johnny Cash may have preferred this galaxy's burning ring of fire to the one he sang about falling into in his popular song. The "starburst ring" seen at center in red and yellow hues is not the product of love, as in the song, but is instead a frenetic region of star formation.

The galaxy, a spiral beauty called Messier 94, is located about 17 million light-years away. In this image from NASA's Spitzer Space Telescope, infrared light is represented in different colors, with blue having the shortest wavelengths and red, the longest.

Starburst rings like this can often be triggered by gravitational encounters with other galaxies but, in this case, may have instead been caused by the galaxy's oval shape. Gas in the ring is being converted into hot, young stars, which then warm the dust, causing it to glow with infrared light.

The outer, faint blue ring around the galaxy might be an optical illusion. Astronomers think that two separate spiral arms appear as a single unbroken ring when viewed from our position in space.

NASA's Jet Propulsion Laboratory, Pasadena, Calif., manages the Spitzer Space Telescope mission for NASA's Science Mission Directorate, Washington. Science operations are conducted at the Spitzer Science Center at the California Institute of Technology in Pasadena. Data are archived at the Infrared Science Archive housed at the Infrared Processing and Analysis Center at Caltech. Caltech manages JPL for NASA.

'Astroarchaeologists' to Revive Dead Satellite

Satellite

It sounds like the opener to a sci-fi B-movie plot: Scientists find an old, dead satellite from the 1970′s orbiting Earth. Out of interest, they send a command to the chunk of space junk to switch it on, just on the off-chance its circuits are still intact…

However, this is not a fictional account of tinkering with 40-year old technology. A British Ph.D. student really wants to wake up an old satellite, one that hasn’t transmitted since 1996.

The satellite, called Prospero X3, is the only British satellite to have been launched by a British rocket in 1971. To commemorate the 40th anniversary of its launch, Roger Duthie and colleagues from University College London’s Mullard Space Science Laboratory (MSSL) want to reestablish contact with the 66 kilogram silent spacecraft.

The satellite, called Prospero X3, is the only British satellite to have been launched by a British rocket in 1971. To commemorate the 40th anniversary of its launch, Roger Duthie and colleagues from University College London’s Mullard Space Science Laboratory (MSSL) want to reestablish contact with the 66 kilogram silent spacecraft.

Prospero was designed to investigate the orbital space environment and its mission was completed in 1973. However, for another two decades the satellite was contacted annually.

Although the program was canceled before Prospero was launched atop a Black Arrow rocket on Oct. 28, 1971, there has been a resurgence in British interests in space. The nation has an active (and profitable) satellite production industry, but since that single 1971 launch, Britain has depended on other space agencies to get their hardware into space.

But last year, the UK Space Agency was set up to oversee all civil interests in space, so the situation is gradually changing.

Therefore, to signify the 40th anniversary of the only British satellite to have ever been launched by a British rocket will be of huge national interest and pride. Enter Duthie who hopes to ‘talk’ with Prospero’s old circuits. Due to the nature of their work, Duthie and his team call themselves “Astro-archaeologists.”

The task to communicate with this spacecraft is no small one, made even more difficult by the fact that the group who used to communicate with the satellite had been disbanded and communication codes were lost.

“The technical reports made in the 1970s were thought to have been lost,” Duthie told BBC News. “We talked to the people involved in Prospero, searched through dusty boxes in attics and tried the library at [the Royal Aircraft Establishment in Farnborough].”

In a stroke of good fortune, Prospero’s codes were found, typed on a piece of paper in the National Archives at Kew, London.

Although they may have the “key” to the spacecraft, the team need to build custom equipment to transmit a signal and get permission from the UK broadcast regulator Ofcom to use the radio frequency now utilized by other satellites in orbit.

Interestingly, once everything is set up on the ground, and if communication is possible — and that’s a big if, space can be a harsh environment for any electronics, regardless of which century they were built — the researchers may find that some of the scientific payload is still operational.

“It’s an artifact of British engineering; we should find out how it’s performing,” said Duthie.

For more on the UK’s Black Arrow rocket, watch the fascinating documentary, “Once We Had a Rocket”: