The Horsehead Nebula (also known as Barnard 33 in emission nebula IC 434) is a dark nebula in the constellation Orion. The nebula is located just to the south of the star Alnitak, which is farthest east on Orion’s Belt, and is part of the much larger Orion Molecular Cloud Complex. The nebula was first recorded in 1888 by Scottish astronomer Williamina Fleming on photographic plate B2312 taken at the Harvard College Observatory. The Horsehead Nebula is approximately 1500 light-years from Earth.
Photographer: Ken Crawford                                            via: Wikipedia

The Horsehead Nebula (also known as Barnard 33 in emission nebula IC 434) is a dark nebula in the constellation Orion. The nebula is located just to the south of the star Alnitak, which is farthest east on Orion’s Belt, and is part of the much larger Orion Molecular Cloud Complex. The nebula was first recorded in 1888 by Scottish astronomer Williamina Fleming on photographic plate B2312 taken at the Harvard College Observatory. The Horsehead Nebula is approximately 1500 light-years from Earth.

Photographer: Ken Crawford                                            via: Wikipedia

The star cluster Pismis 24 lies in the core of the large emission nebula NGC 6357, which extends one degree on the sky in the direction of the constellation Scorpius. Part of the nebula is ionised by the youngest (bluest) heavy stars in Pismis 24. The intense ultraviolet radiation from the blazing stars heats the gas surrounding the cluster and creates a bubble in NGC 6357. The brightest point of light above the centre of this image is Pismis 24-1, once thought to be the most massive known star but now known to be a binary system.
Photograph: HST/NASA/ESA                                                via: Wikipedia

The star cluster Pismis 24 lies in the core of the large emission nebula NGC 6357, which extends one degree on the sky in the direction of the constellation Scorpius. Part of the nebula is ionised by the youngest (bluest) heavy stars in Pismis 24. The intense ultraviolet radiation from the blazing stars heats the gas surrounding the cluster and creates a bubble in NGC 6357. The brightest point of light above the centre of this image is Pismis 24-1, once thought to be the most massive known star but now known to be a binary system.

Photograph: HST/NASA/ESA                                                via: Wikipedia

Ultra-Violet Light
Ultraviolet (UV) light has shorter wavelengths than visible light. Although UV waves are invisible to the human eye, some insects, such as bumblebees, can see them. This is similar to how a dog can hear the sound of a whistle just outside the hearing range of humans. The Sun is a source of the full spectrum of ultraviolet radiation, which is commonly subdivi…ded into UV-A, UV-B, and UV-C. These are the classifications most often used in Earth sciences. UV-C rays are the most harmful and are almost completely absorbed by our atmosphere. UV-B rays are the harmful rays that cause sunburn. Exposure to UV-B rays increases the risk of DNA and other cellular damage in living organisms. Fortunately, about 95 percent UV-B rays are absorbed by ozone in the Earth’s atmosphere. Seen here is a full-disk multiwavelength extreme ultraviolet image of the sun taken by NASA’s Solar Dynamics Observatory on March 30, 2010. False colors trace different gas temperatures. Reds are relatively cool (about 60,000 Kelvin, or 107,540 F); blues and greens are hotter (greater than 1 million Kelvin, or 1,799,540 F).Credit: NASA/Goddard/SDO AIA Team
(via: NASA)

Ultra-Violet Light

Ultraviolet (UV) light has shorter wavelengths than visible light. Although UV waves are invisible to the human eye, some insects, such as bumblebees, can see them. This is similar to how a dog can hear the sound of a whistle just outside the hearing range of humans.

The Sun is a source of the full spectrum of ultraviolet radiation, which is commonly subdivided into UV-A, UV-B, and UV-C. These are the classifications most often used in Earth sciences. UV-C rays are the most harmful and are almost completely absorbed by our atmosphere. UV-B rays are the harmful rays that cause sunburn. Exposure to UV-B rays increases the risk of DNA and other cellular damage in living organisms. Fortunately, about 95 percent UV-B rays are absorbed by ozone in the Earth’s atmosphere.

Seen here is a full-disk multiwavelength extreme ultraviolet image of the sun taken by NASA’s Solar Dynamics Observatory on March 30, 2010. False colors trace different gas temperatures. Reds are relatively cool (about 60,000 Kelvin, or 107,540 F); blues and greens are hotter (greater than 1 million Kelvin, or 1,799,540 F).

Credit: NASA/Goddard/SDO AIA Team

(via: NASA)

On April 8th, Earth will soar between the Sun and Mars.

When it does, the Red Planet will reach what astronomers call “opposition” in the night sky. Just a few days later, Earth will be closer to Mars than it’s been in more than six years. The resulting views should be extraordinary. Here’s what you need to know to catch a glimpse yourself…

Does Dark Energy Spring From the ‘Quantum Vacuum?’
by Mike Wall
The mysterious dark energy that’s driving the universe’s accelerated expansion may have its roots in the background “vacuum energy” that pervades all of the cosmos, a new study suggests.

"What we think is happening is a dynamic effect of the quantum vacuum, a parameter that we can calculate," co-author Joan Sola, of the University of Barcelona in Spain, said in a statement. "Nothing is more ‘full’ than the quantum vacuum since it is full of fluctuations that contribute fundamentally to the values that we observe and measure."
Though dark energy constitutes about 75 percent of the universe, scientists don’t know exactly what it is. They’ve developed several different ideas, including the theory of “quintessence,” which proposes a sort of anti-gravitating agent that repels rather than attracts…
(read more: Live Science)
image: European Space Agency

Does Dark Energy Spring From the ‘Quantum Vacuum?’

by Mike Wall

The mysterious dark energy that’s driving the universe’s accelerated expansion may have its roots in the background “vacuum energy” that pervades all of the cosmos, a new study suggests.

"What we think is happening is a dynamic effect of the quantum vacuum, a parameter that we can calculate," co-author Joan Sola, of the University of Barcelona in Spain, said in a statement. "Nothing is more ‘full’ than the quantum vacuum since it is full of fluctuations that contribute fundamentally to the values that we observe and measure."

Though dark energy constitutes about 75 percent of the universe, scientists don’t know exactly what it is. They’ve developed several different ideas, including the theory of “quintessence,” which proposes a sort of anti-gravitating agent that repels rather than attracts…

(read more: Live Science)

image: European Space Agency

Small World Spotted Far Beyond Pluto

by Ken Crosswell

Astronomers have detected a small world (inset) more than twice as remote as Pluto, lying 12 billion kilometers, or 83 AU, from the sun. (One AU, or astronomical unit, is the mean sun-Earth distance.)

As scientists report online today in Nature, the new object is the first ever found whose orbit (red curve) resembles that of Sedna (orange curve), a far-off body that never gets close to Neptune’s path (outermost magenta circle). Both Sedna and the new world, designated 2012 VP113, therefore differ from Pluto and other members of the Edgeworth-Kuiper belt (turquoise dots), which lie just past Neptune’s orbit.

The object journeys 80 to 452 AU from the sun, never approaching Neptune (30 AU) or Pluto (39.5 AU). The new world is roughly 450 kilometers across, just one-fifth Pluto’s diameter

(read more: Science News/AAAS)

images: Scott S. Sheppard/Carnegie Institution for Science

A Hypergiant Star And Its Clingy Companion
This enormous star is a million times brighter than the sun.
by Francie Diep
The astronomer who discovered the size of this star says it’s shaped like a peanut, but we disagree; that one “lobe” is much too large. Perhaps that’s because the larger star is, in fact, one of the 10 largest stars ever discovered. Its diameter is 1,315 times that of Earth’s sun.
Astronomers have seen the star, named HR 5171, before. In a new study, however, an international team of scientists learned much more about it. For example, they discovered that HR 5171 is a binary system with a small companion star that touches and orbits the larger star. The astronomers also calculated HR 5171 A’s (the bigger star’s) surprising size. The star is almost twice as large as scientists expect for stars of its type.
HR 5171 A is a yellow hypergiant, a type of star that’s rare in our galaxy. Like its type-mates, HR 5171 A is big, bright and unstable. It’s about 1 million times brighter than the sun. Over the past four decades, it’s been cooling, enlarging and expelling material outwards…
(read more: Popular Science)
image: European Southern Observatory

A Hypergiant Star And Its Clingy Companion

This enormous star is a million times brighter than the sun.

by Francie Diep

The astronomer who discovered the size of this star says it’s shaped like a peanut, but we disagree; that one “lobe” is much too large. Perhaps that’s because the larger star is, in fact, one of the 10 largest stars ever discovered. Its diameter is 1,315 times that of Earth’s sun.

Astronomers have seen the star, named HR 5171, before. In a new study, however, an international team of scientists learned much more about it. For example, they discovered that HR 5171 is a binary system with a small companion star that touches and orbits the larger star. The astronomers also calculated HR 5171 A’s (the bigger star’s) surprising size. The star is almost twice as large as scientists expect for stars of its type.

HR 5171 A is a yellow hypergiant, a type of star that’s rare in our galaxy. Like its type-mates, HR 5171 A is big, bright and unstable. It’s about 1 million times brighter than the sun. Over the past four decades, it’s been cooling, enlarging and expelling material outwards…

(read more: Popular Science)

image: European Southern Observatory

Scientists Totally Surprised By Saturn Like Rings Found Around Asteroid

by Sid Perkins

Even before astronomers pointed their telescopes at a dim star over Chile last June, they knew it would darken for a few seconds as an asteroid passed in front of it. What they didn’t expect were two brief flickers a few seconds beforehand and afterward, suggesting that the asteroid was encircled by Saturn-like rings. The find is the first evidence for such rings around anything in our solar system other than a giant planet.

Like other teams positioned in a 1500-kilometer-wide swath across South America, the astronomers had started out the night with one mission: They intended to measure the size of Chariklo, an icy body that circles the sun between the orbits of Saturn and Uranus. Knowing Chariklo’s speed across the sky, they could use the duration of the mini-eclipse to estimate the distant asteroid’s size, says Felipe Braga-Ribas, an astronomer at the National Observatory in Rio de Janeiro, Brazil.

“But then we saw the flickers,” he says. Because the team members weren’t looking for a ring, the discovery came as a complete surprise, he notes…

(read more: Science News/AAAS)

illustrations by Lucie Maquet

Black Holes have Simple Feeding Habits
This composite NASA image of the spiral galaxy M81, located about 12 million light years away, includes X-ray data from the Chandra X-ray Observatory (blue), optical data from the Hubble Space Telescope (green), infrared data from the Spitzer Space Telescope (pink) and ultraviolet data from GALEX (purple). The inset shows a close-up of the Chandra image. At the center of M81 is a supermassive black hole that is about 70 million times more massive than the Sun.
A new study using data from Chandra and ground-based telescopes, combined with detailed theoretical models, shows that the supermassive black hole in M81 feeds just like stellar mass black holes, with masses of only about ten times that of the Sun. This discovery supports the implication of Einstein’s relativity theory that black holes of all sizes have similar properties, and will be useful for predicting the properties of a conjectured new class of black holes…
(read more: Chandra X-Ray Observatory)

Black Holes have Simple Feeding Habits

This composite NASA image of the spiral galaxy M81, located about 12 million light years away, includes X-ray data from the Chandra X-ray Observatory (blue), optical data from the Hubble Space Telescope (green), infrared data from the Spitzer Space Telescope (pink) and ultraviolet data from GALEX (purple). The inset shows a close-up of the Chandra image. At the center of M81 is a supermassive black hole that is about 70 million times more massive than the Sun.

A new study using data from Chandra and ground-based telescopes, combined with detailed theoretical models, shows that the supermassive black hole in M81 feeds just like stellar mass black holes, with masses of only about ten times that of the Sun. This discovery supports the implication of Einstein’s relativity theory that black holes of all sizes have similar properties, and will be useful for predicting the properties of a conjectured new class of black holes…

(read more: Chandra X-Ray Observatory)

Stellar Shrapnel Seen in Aftermath of Explosion
This beautiful composite image shows N49, the aftermath of a supernova explosion in the Large Magellanic Cloud. A new long observation from NASA’s Chandra X-ray Observatory, shown in blue, reveals evidence for a bullet-shaped object being blown out of a debris field left over from an exploded star.
In order to detect this bullet, a team of researchers led by Sangwook Park of Penn State University used Chandra to observe N49 for over 30 hours. This bullet can be seen in the bottom right hand corner of the image (roll your mouse over the image above or click here) and is rich in silicon, sulphur and neon. The detection of this bullet shows that the explosion that destroyed the star was highly asymmetric…
(read more: Chandra X-Ray Observatory)

Stellar Shrapnel Seen in Aftermath of Explosion

This beautiful composite image shows N49, the aftermath of a supernova explosion in the Large Magellanic Cloud. A new long observation from NASA’s Chandra X-ray Observatory, shown in blue, reveals evidence for a bullet-shaped object being blown out of a debris field left over from an exploded star.

In order to detect this bullet, a team of researchers led by Sangwook Park of Penn State University used Chandra to observe N49 for over 30 hours. This bullet can be seen in the bottom right hand corner of the image (roll your mouse over the image above or click here) and is rich in silicon, sulphur and neon. The detection of this bullet shows that the explosion that destroyed the star was highly asymmetric…

(read more: Chandra X-Ray Observatory)

A gas cloud collides with the black hole at the center of our galaxy, and we get to watch
by Jenny Marder
The landscape in Chile’s Atacama desert is Martian-like: dry, barren and flanked by volcanoes, and its high altitude and unpolluted skies make it a prime spot for stargazing. It was there, after a full night of such observation — and over a 4 p.m. breakfast — that astronomer Stefan Gillessen found himself in possession of some very special data. His observations showed a cloud of gas being stretched out, or “spaghettified,” about to be ripped apart, as it barreled toward the black hole at the center of our galaxy.
He and his team at the Max Planck Institute for Extraterrestrial Physics in Germany had been observing Sagittarius A*, the supermassive black hole, using the European Southern Observatory’s Very Large Telescope in Chile. And for nearly a decade, they had been sitting on a batch of low-resolution data. When the atmospheric conditions are poor, it is common to use the telescope’s adaptive optics system at longer wavelengths, which allows scientists to still peer through the atmospheric turbulence, but compromises the sharpness of the image. It was in 2011 that he decided to systematically study this coarser data…
(read more: PBS.or - The News Hour)
image: This simulation shows the G2 gas cloud during its close approach to the black hole at the center of the Milky Way. Image by ESO/MPE/Marc Schartmann.

A gas cloud collides with the black hole at the center of our galaxy, and we get to watch

by Jenny Marder

The landscape in Chile’s Atacama desert is Martian-like: dry, barren and flanked by volcanoes, and its high altitude and unpolluted skies make it a prime spot for stargazing. It was there, after a full night of such observation — and over a 4 p.m. breakfast — that astronomer Stefan Gillessen found himself in possession of some very special data. His observations showed a cloud of gas being stretched out, or “spaghettified,” about to be ripped apart, as it barreled toward the black hole at the center of our galaxy.

He and his team at the Max Planck Institute for Extraterrestrial Physics in Germany had been observing Sagittarius A*, the supermassive black hole, using the European Southern Observatory’s Very Large Telescope in Chile. And for nearly a decade, they had been sitting on a batch of low-resolution data. When the atmospheric conditions are poor, it is common to use the telescope’s adaptive optics system at longer wavelengths, which allows scientists to still peer through the atmospheric turbulence, but compromises the sharpness of the image. It was in 2011 that he decided to systematically study this coarser data…

(read more: PBS.or - The News Hour)

image: This simulation shows the G2 gas cloud during its close approach to the black hole at the center of the Milky Way. Image by ESO/MPE/Marc Schartmann.

NGC 4565 (also known as the Needle Galaxy) is an edge-on spiral galaxy about 30 to 50 million light-years away in the constellation Coma Berenices. NGC 4565 is a giant spiral galaxy more luminous than the Andromeda Galaxy, and has a population of roughly 240 globular clusters, more than the Milky Way.
Photographer: Ken Crawford                                                     via: Wikipedia

NGC 4565 (also known as the Needle Galaxy) is an edge-on spiral galaxy about 30 to 50 million light-years away in the constellation Coma Berenices. NGC 4565 is a giant spiral galaxy more luminous than the Andromeda Galaxy, and has a population of roughly 240 globular clusters, more than the Milky Way.

Photographer: Ken Crawford                                                     via: Wikipedia