Tag: astronomy
Has Dark Matter been detected?
A slew of exoplanets
Using two European-built ground-based telescopes in Chile, astronomers have announced today the discovery of 50 new exoplanets, 16 of which are considered super Earths, one of which is in the habitable zone of its star. You can read the preprint of their research paper here [pdf].
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A giant storm on a distant star
Astronomers have spotted what they think is a giant storm on a distant star.
As part of a large survey of nearby brown dwarfs – objects that occupy the mass gap between dwarf stars and giant planets – the scientists used an infrared camera on the 2.5m telescope at Las Campanas Observatory in Chile to capture repeated images of a brown dwarf dubbed 2MASS J21392676+0220226, or 2MASS 2139 for short, over several hours. In that short time span, they recorded the largest variations in brightness ever seen on a cool brown dwarf.
“We found that our target’s brightness changed by a whopping 30 per cent in just under eight hours,” said PhD candidate Jacqueline Radigan, lead author of a paper to be presented this week at the Extreme Solar Systems II conference in Jackson Hole, Wyoming and submitted to the Astrophysical Journal. “The best explanation is that brighter and darker patches of its atmosphere are coming into our view as the brown dwarf spins on its axis,” said Radigan.
Astronomers have spotted what they think is a giant storm on a distant star.
As part of a large survey of nearby brown dwarfs – objects that occupy the mass gap between dwarf stars and giant planets – the scientists used an infrared camera on the 2.5m telescope at Las Campanas Observatory in Chile to capture repeated images of a brown dwarf dubbed 2MASS J21392676+0220226, or 2MASS 2139 for short, over several hours. In that short time span, they recorded the largest variations in brightness ever seen on a cool brown dwarf.
“We found that our target’s brightness changed by a whopping 30 per cent in just under eight hours,” said PhD candidate Jacqueline Radigan, lead author of a paper to be presented this week at the Extreme Solar Systems II conference in Jackson Hole, Wyoming and submitted to the Astrophysical Journal. “The best explanation is that brighter and darker patches of its atmosphere are coming into our view as the brown dwarf spins on its axis,” said Radigan.
Twin GRAIL gravity probes on the way to the moon
The twin GRAIL gravity probes launched successfully on Saturday and are now on their way to the moon.
The twin GRAIL gravity probes launched successfully on Saturday and are now on their way to the moon.
Symphony of Science
Unknown objects in space
NASA’s Fermi Gamma-Ray Telescope today released an updated catalog of the last two years of its survey of the sky at high energy emissions. All told, there are 1873 objects in the catalog, more than half of which are supermassive black holes at the center of distant galaxies. You can see this all-sky map below the fold.
Many of the objects are quite familiar, such as the Crab Nebula, the remnant of a supernova that exploded a little less than a thousand years ago.
For decades, most astronomers regarded the Crab Nebula as the steadiest beacon at X-ray energies. But data from several orbiting instruments — including Fermi’s Gamma-ray Burst Monitor — now show unexpected variations. Astronomers have shown that since 2008, the nebula has faded by 7 percent at high energies, a reduction likely tied to the environment around its central neutron star.
Since 2007, Fermi and the Italian Space Agency’s AGILE satellite have detected several short-lived gamma-ray flares at energies hundreds of times higher than the nebula’s observed X-ray variations. In April, the satellites detected two of the most powerful yet recorded. To account for these “superflares,” scientists say that electrons near the pulsar must be accelerated to energies a thousand trillion times greater than that of visible light — and far beyond what can be achieved by the Large Hadron Collider near Geneva, Switzerland, now the most powerful particle accelerator on Earth.
What I, and many astronomers, find even most interesting about this catalog, however, is the large number of completely mysterious objects scattered across the sky, objects that emit powerful gamma rays but are not visible in any other wavelengths. All told, these unidentified objects comprise almost one third of the entire catalog.
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Nearest supernova in a quarter century now visible with binoculars
The nearest supernova in almost a quarter century is now visible using binoculars.
The nearest supernova in almost a quarter century is now visible using binoculars.
Baby Star Found on Earth’s Doorstep
A baby star has been found only 27 light years away.
AP Columbae lies in the constellation Columba the Dove, south of the brilliant constellation Orion. “AP Columbae is still contracting under gravity towards the main sequence,” says astronomer Adric Riedel of Georgia State University in Atlanta, whose team measured the star’s parallax—an indication of its distance—and discovered that the star is abnormally luminous. Although the star is dim and red, it’s four times as bright as it should be, because it’s twice the diameter of a main-sequence star of the same color.
A baby star has been found only 27 light years away.
AP Columbae lies in the constellation Columba the Dove, south of the brilliant constellation Orion. “AP Columbae is still contracting under gravity towards the main sequence,” says astronomer Adric Riedel of Georgia State University in Atlanta, whose team measured the star’s parallax—an indication of its distance—and discovered that the star is abnormally luminous. Although the star is dim and red, it’s four times as bright as it should be, because it’s twice the diameter of a main-sequence star of the same color.
Kepler team pushes for mission extension
The Kepler team pushes for a mission extension in order to find Earth-sized planets.
The Kepler spacecraft has hit an unexpected obstacle as it patiently watches the heavens for exoplanets: too many rowdy young stars. The orbiting probe detects small dips in the brightness of a star that occur when a planet crosses its face. But an analysis of some 2,500 of the tens of thousands of Sun-like stars detected in Kepler’s field of view has found that the stars themselves flicker more than predicted, with the largest number varying twice as much as the Sun. That makes it harder to detect Earth-sized bodies. As a result, the analysis suggests that Kepler will need more than double its planned mission life of three-and-a-half years to achieve its main goal of determining how common Earth-like planets are in the Milky Way.
While it is important to find those Earth-sized planets, to me the important discovery here is that Kepler is confirming what previous research has suggested: Stars like our Sun are generally far more active and variable than the Sun itself. Which means that either the Sun is unusual, or has been unusually inactive during recorded human history.
The Kepler team pushes for a mission extension in order to find Earth-sized planets.
The Kepler spacecraft has hit an unexpected obstacle as it patiently watches the heavens for exoplanets: too many rowdy young stars. The orbiting probe detects small dips in the brightness of a star that occur when a planet crosses its face. But an analysis of some 2,500 of the tens of thousands of Sun-like stars detected in Kepler’s field of view has found that the stars themselves flicker more than predicted, with the largest number varying twice as much as the Sun. That makes it harder to detect Earth-sized bodies. As a result, the analysis suggests that Kepler will need more than double its planned mission life of three-and-a-half years to achieve its main goal of determining how common Earth-like planets are in the Milky Way.
While it is important to find those Earth-sized planets, to me the important discovery here is that Kepler is confirming what previous research has suggested: Stars like our Sun are generally far more active and variable than the Sun itself. Which means that either the Sun is unusual, or has been unusually inactive during recorded human history.
The Hubble Space Telescope: Movie camera!
Using Hubble Space Telescope images taken over a 14 year period, a team of astronomers led by Patrick Hartigan of Rice University have produced six very short time-lapse movies, showing the changes that have occurred to a variety of interstellar jets and bow shocks over time. The one below is my favorite. They are all worth looking at, as they illustrate forcefully how the changeless heavens are not so changeless.
Juno looks back and sees the Earth and the Moon
Juno, on its way to Jupiter, took a look back and snapped this picture of the Earth/Moon double planet.
The image was taken by the spacecraft’s camera, JunoCam, on Aug. 26 when the spacecraft was about 6 million miles (9.66 million kilometers) away.
Gives us a glimpse at what our home planet will really look like to future spacefarers, either on they way out or on their way home.
Juno, on its way to Jupiter, took a look back and snapped this picture of the Earth/Moon double planet.
The image was taken by the spacecraft’s camera, JunoCam, on Aug. 26 when the spacecraft was about 6 million miles (9.66 million kilometers) away.
Gives us a glimpse at what our home planet will really look like to future spacefarers, either on they way out or on their way home.
Star goes boom, telescopes zoom
Big Sky Country – A Montana night sky time lapse
An evening pause: In Glacier National Park in August 2011. From Mark “Indy” Kochte.
Comets Elenin & Garradd Now Showing in Night Sky
Get out those binoculars! Two comets, Elenin and Garradd, are now showing in the night sky.
Get out those binoculars! Two comets, Elenin and Garradd, are now showing in the night sky.
The closest supernovae in almost 25 years
Astronomers have spotted the closest supernovae in almost 25 years, only 21 million light years away.
The supernova, dubbed PTF 11kly, occurred in the Pinwheel Galaxy, located in the “Big Dipper,” otherwise known as the Ursa Major constellation. It was discovered by the Palomar Transient Factory (PTF) survey, which is designed to observe and uncover astronomical events as they happen. “We caught this supernova very soon after explosion. PTF 11kly is getting brighter by the minute. It’s already 20 times brighter than it was yesterday,” said Peter Nugent, the senior scientist at Berkeley Lab who first spotted the supernova. Nugent is also an adjunct professor of astronomy at UC Berkeley. “Observing PTF 11kly unfold should be a wild ride. It is an instant cosmic classic.”
Astronomers expect the supernova to continue to brighten over the next two weeks, when it should be visible to anyone using binoculars.
Astronomers have spotted the closest supernovae in almost 25 years, only 21 million light years away.
The supernova, dubbed PTF 11kly, occurred in the Pinwheel Galaxy, located in the “Big Dipper,” otherwise known as the Ursa Major constellation. It was discovered by the Palomar Transient Factory (PTF) survey, which is designed to observe and uncover astronomical events as they happen. “We caught this supernova very soon after explosion. PTF 11kly is getting brighter by the minute. It’s already 20 times brighter than it was yesterday,” said Peter Nugent, the senior scientist at Berkeley Lab who first spotted the supernova. Nugent is also an adjunct professor of astronomy at UC Berkeley. “Observing PTF 11kly unfold should be a wild ride. It is an instant cosmic classic.”
Astronomers expect the supernova to continue to brighten over the next two weeks, when it should be visible to anyone using binoculars.
Asteroid dust from Hayabusa prove origin of the most common meteorites
Asteroid dust from Hayabusa have been linked to the origin of the most common meteorite types found on Earth.
Asteroid dust from Hayabusa have been linked to the origin of the most common meteorite types found on Earth.
When dust, pebbles, rocks, and boulders act like liquid
The science team of Lunar Reconnaissance Orbiter released an intriguing picture yesterday of what scientists call a granular flow down the side of a five mile wide crater on the far side of the moon. Looking at the image, one would swear that the darker material flowing down the slope of the crater rim is a lava flow frozen in place.
However, according to the scientists, that is not what it is. Instead, this is merely debris left behind from an avalanche.
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Astronomers discover planet made of diamond
Astronomers have discovered a planet literally made of diamond.
The new planet is far denser than any other known so far and consists largely of carbon. Because it is so dense, scientists calculate the carbon must be crystalline, so a large part of this strange world will effectively be diamond.
Astronomers have discovered a planet literally made of diamond.
The new planet is far denser than any other known so far and consists largely of carbon. Because it is so dense, scientists calculate the carbon must be crystalline, so a large part of this strange world will effectively be diamond.
Stars as cold as the human body
Watching a black hole devour a star, 3.9 billion light years away
Watching a black hole devour a star, 3.9 billion light years away.
Watching a black hole devour a star, 3.9 billion light years away.
Super-Earth spotted on the edge of habitable zone
A super-Earth has been identified orbiting its star on the edge of the habitable zone.
A super-Earth has been identified orbiting its star on the edge of the habitable zone.
NASA pushes for funds to save the James Webb Space Telescope
NASA pushes for funds to save the James Webb Space Telescope.
NASA pushes for funds to save the James Webb Space Telescope.
The American Eclipse of 2017
Time to start making your vacation plans. On August 21, 2017 a total eclipse of the sun is going to traverse the entire length of the continental United States, from Oregon to South Carolina. Kentucky will have the longest view, with totality as long as three minutes.
And astronomers are already thinking of ways to harness the help of the American people in observing this event. In a paper published today on the Los Alamos astro-ph website, a team of astronomers are proposing organizing something they have dubbed the U.S. Eclipse MegaMovie, whereby they gather together as many images of the totality as possible and assemble them into a single film, showing the evolution of the sun’s corona as it crosses the continent.
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A map of the core region of the Milky Way
The mystery of Vesta’s south pole depression
The mystery of Vesta’s south pole depression.
The mystery of Vesta’s south pole depression.
Hubble captures a necklace in space
Who needs aliens and imagined cities on the moon when you have a reality that produces such strange and beautiful things as the image on the right?
On July 2, the Hubble Space Telescope took this image of a planetary nebula, aptly dubbed the Necklace Nebula. As the caption explains,
A pair of stars orbiting close together produced the nebula, also called PN G054.2-03.4. About 10,000 years ago one of the aging stars ballooned to the point where it engulfed its companion star. The smaller star continued orbiting inside its larger companion, increasing the giant’s rotation rate.
The bloated companion star spun so fast that a large part of its gaseous envelope expanded into space. Due to centrifugal force, most of the gas escaped along the star’s equator, producing a ring. The embedded bright knots are dense gas clumps in the ring.
The binary still exists, and can be seen as the star in the center of the necklace. The two stars are now only a few million miles apart and complete an orbit around each other in about a day.
Oxygen molecules detected in star-forming region
Oxygen molecules have been detected for the first time in space, and they were found in the Orion nebula, a giant molecular cloud where stars are being born. More here.
Oxygen molecules have been detected for the first time in space, and they were found in the Orion nebula, a giant molecular cloud where stars are being born. More here.
Astronomers identify Earth’s first Trojan asteroid
Astronomers have spotted the first Trojan asteroid to the Earth.
The asteroid is roughly 1,000 feet (300 meters) in diameter. It has an unusual orbit that traces a complex motion near a stable point in the plane of Earth’s orbit, although the asteroid also moves above and below the plane. The object is about 50 million miles (80 million kilometers) from Earth. The asteroid’s orbit is well-defined and for at least the next 100 years, it will not come closer to Earth than 15 million miles (24 million kilometers).
Astronomers have spotted the first Trojan asteroid to the Earth.
The asteroid is roughly 1,000 feet (300 meters) in diameter. It has an unusual orbit that traces a complex motion near a stable point in the plane of Earth’s orbit, although the asteroid also moves above and below the plane. The object is about 50 million miles (80 million kilometers) from Earth. The asteroid’s orbit is well-defined and for at least the next 100 years, it will not come closer to Earth than 15 million miles (24 million kilometers).
Enceladus rains water onto Saturn
The Herschel space telescope has discovered that the water expelled from the tiger stripes on Enceladus eventually rains down on Saturn.
Enceladus expels around 250 kg of water vapour every second, through a collection of jets from the south polar region known as the Tiger Stripes because of their distinctive surface markings. These crucial observations reveal that the water creates a doughnut-shaped torus of vapour surrounding the ringed planet. The total width of the torus is more than 10 times the radius of Saturn, yet it is only about one Saturn radius thick. Enceladus orbits the planet at a distance of about four Saturn radii, replenishing the torus with its jets of water.
The Herschel space telescope has discovered that the water expelled from the tiger stripes on Enceladus eventually rains down on Saturn.
Enceladus expels around 250 kg of water vapour every second, through a collection of jets from the south polar region known as the Tiger Stripes because of their distinctive surface markings. These crucial observations reveal that the water creates a doughnut-shaped torus of vapour surrounding the ringed planet. The total width of the torus is more than 10 times the radius of Saturn, yet it is only about one Saturn radius thick. Enceladus orbits the planet at a distance of about four Saturn radii, replenishing the torus with its jets of water.
The Russian orbiting radio telescope has unfurled its 10 meter dish
The Russian orbiting radio telescope Spektr-R has successfully unfurled its 10 meter dish.
The Russian orbiting radio telescope Spektr-R has successfully unfurled its 10 meter dish.