Major Volcanic Eruption Seen on Jupiter’s Moon Io

Recent observations of Jupiter’s moon Io has revealed a massive volcanic eruption taking place 628,300,000 km (390,400,000 miles) from Earth. Io, the innermost of the four largest moons around Jupiter, is the most volcanically active object in the Solar System with about 240 active regions. But this new one definitely caught the eye of Dr. Imke de Pater, Professor of Astronomy and of Earth and Planetary Science at the University of California in Berkeley. She was using the Keck II telescope on Mauna Kea in Hawaii on August 15, 2013 when it immediately became apparent something big was happening at Io.

“When you are right at the telescope and see the data, this is something you can see immediately, especially with a big eruption like that,” de Pater told Universe Today via phone.

de Pater said this eruption is one of the top 10 most powerful eruptions that have been seen on this moon. “It is a very energetic eruption that covers over a 30 square kilometer area,” she said. “For Earth, that is big, and for Io it is very big too. It really is one of the biggest eruptions we have seen.”

She added the new volcano appears to have a large energy output. “We saw a big eruption in 2001, which was in the Surt region, which is well known as the biggest one anyone has ever seen,” she said. “For this one, the total energy is less but per square meter, it is bigger than the one in 2001, so it is very powerful.”

While Io’s eruptions can’t be seen directly from Earth,infrared cameras on the Keck telescope (looking between 1 and 5 microns) have been able to ascertain there are likely fountains of lava gushing from fissures in the Rarog Patera region of Io, aptly named for a Czech fire deity.

While many regions of Io are volcanically active, de Pater said she’s not been able to find any other previous activity that has been reported in the Rarog Patera area, which the team finds very interesting.

Ashley Davies of NASA’s Jet Propulsion Laboratory in Pasadena, California and a member of the observing team told Universe Today that Rarog Patera was identified as a small, relatively innocuous hot spot previously in Galileo PPR data and possibly from Earth, but at a level way, way below what was seen on August 15, and reported in New Scientist.

de Pater and other astronomers will be taking more data soon with Keck and perhaps more telescopes to try and find out more about this massive eruption.

“We never know about eruptions – they can last hours, days months or years, so we have no idea how long it will stay active,” she said, “but we are very excited about it.”

No data or imagery has been released on the new eruption yet since the team is still making their observations and will be writing a paper on this topic.

Scientists think a gravitational tug-of-war with Jupiter is one cause of Io’s intense vulcanism.

Rain is Falling from Saturn’s Rings

Astronomers have known for years there was water in Saturn’s upper atmosphere, but they weren’t sure exactly where it was coming from. New observations have found water is raining down on Saturn, and it is coming from the planet’s rings.

“Saturn is the first planet to show significant interaction between its atmosphere and ring system,” said James O’Donoghue, a postgraduate researcher at the University of Leicester and author of a new paper published in the journal Nature. “The main effect of ring rain is that it acts to ‘quench’ the ionosphere of Saturn, severely reducing the electron densities in regions in which it falls.”

Using the Keck Observatory, O’Donoghue and a team of researchers found charged water particles falling from the planet’s rings into Saturn’s atmosphere. They also found the extent of the ring-rain is far greater, and falls across larger areas of the planet, than previously thought. The work reveals the rain influences the composition and temperature structure of parts of Saturn’s upper atmosphere.

O’Donoghue said the ring’s effect on electron densities is important because it explains why, for many decades, observations have shown electron densities to be unusually low at some latitudes at Saturn.

“It turns out a major driver of Saturn’s ionospheric environment and climate across vast reaches of the planet are ring particles located 120,000 miles [200,000 kilometers] overhead,” said Kevin Baines, a co-author on the paper, from the Jet Propulsion Laboratory. “The ring particles affect which species of particles are in this part of the atmospheric temperature.”

In the early 1980s, images from NASA’s Voyager spacecraft showed two to three dark bands on Saturn and scientists theorized that water could have been showering down into those bands from the rings. Then astronomers using ESA’s Infrared Observatory discovered the presence of trace amounts of water in Saturn’s atmosphere back in 1997, but couldn’t really find an explanation for why it was there and how it got there.

Then in 2011 observations with the Herschel space observatory determined water ice from geysers on Enceladus formed a giant ring of water vapor around Saturn.

But the bands seen by Voyager were not seen again until 2011 as well, when the team observed the planet with Keck Observatory’s NIRSPEC, a near-infrared spectrograph that combines broad wavelength coverage with high spectral resolution, allowing the observers to clearly see subtle emissions from the bright parts of Saturn.

The ring rain’s effect occurs in Saturn’s ionosphere (Earth has a similar ionosphere), where charged particles are produced when the otherwise neutral atmosphere is exposed to a flow of energetic particles or solar radiation. When the scientists tracked the pattern of emissions of a particular hydrogen molecule consisting of three hydrogen atoms (rather than the usual two), they expected to see a uniform planet-wide infrared glow.

What they observed instead was a series of light and dark bands with a pattern mimicking the planet’s rings. Saturn’s magnetic field “maps” the water-rich rings and the water-free gaps between rings onto the planet’s atmosphere.

They surmised that charged water particles from the planet’s rings were being drawn towards the planet by Saturn’s magnetic field and neutralizing the glowing triatomic hydrogen ions. This leaves large “shadows” in what would otherwise be a planet-wide infrared glow. These shadows cover 30 to 43 percent of the planet’s upper atmosphere surface from around 25 to 55 degrees latitude. This is a significantly larger area than suggested by the Voyager images.

Both Earth and Jupiter have a very uniformly glowing equatorial region. Scientists expected this pattern at Saturn, too, but they instead saw dramatic differences at different latitudes.

“Where Jupiter is glowing evenly across its equatorial regions, Saturn has dark bands where the water is falling in, darkening the ionosphere,” said Tom Stallard, one of the paper’s co-authors at Leicester. “We’re now also trying to investigate these features with an instrument on NASA’s Cassini spacecraft. If we’re successful, Cassini may allow us to view in more detail the way that water is removing ionized particles, such as any changes in the altitude or effects that come with the time of day.”

Sources: Keck Observatory
, Nature.

Exoplanet Atmospheres Provide Clues to Solar System Formation

The most detailed look yet at the atmosphere of a distant exoplanet has revealed a mixture of water vapor and carbon monoxide blanketing a world ten times the size of Jupiter about 130 light years away from Earth. But even with water present on this world, it is incredibly hostile to life. Like Jupiter, it has no solid surface, and it has a temperature of more than a thousand degree. Additionally, no tell-tale methane signals were detected in the atmosphere. But this solar system is still of great interest, as three other giant worlds orbit the same star and scientists said studying this system will not only help solve mysteries of how it was formed, but also how our own solar system formed as well.

The observations were made at the Keck II telescope in Hawaii, using an infrared imaging spectrograph called OSIRIS, which was able to uncover the chemical fingerprints of specific molecules.

“This is the sharpest spectrum ever obtained of an extrasolar planet,” said Dr. Bruce Macintosh, from the Lawrence Livermore National Laboratory. “This shows the power of directly imaging a planetary system. It is the exquisite resolution afforded by these new observations that has allowed us to really begin to probe planet formation.”

“With this level of detail,” said co-author Travis Barman from the Lowell Observatory, “we can compare the amount of carbon to the amount of oxygen present in the atmosphere, and this chemical mix provides clues as to how the planetary system formed.”

Artist’s rendering of HR 8799c at an early stage in the evolution of the planetary system, showing the planet, a disk of gas and dust, rocky inner planets, and HR 8799. Credit: Dunlap Institute for Astronomy & Astrophysics
Artist’s rendering of HR 8799c at an early stage in the evolution of the planetary system, showing the planet, a disk of gas and dust, rocky inner planets, and HR 8799.
Credit: Dunlap Institute for Astronomy & Astrophysics

The planets around the star, known as HR 8799, weigh in between five to 10 times the mass of Jupiter and are still glowing in infrared with the heat of their formation. The research team says their observations suggest the solar system was created in a similar way to our own, with gas giants forming far away from their parent star and smaller, rocky planets closer in. However, no Earth-like rocky planets have yet been detected in this system.

“The results suggest the HR 8799 system is like a scaled-up Solar System,” said Quinn Kanopacky, an astronomer from the University of Toronto in Canada. “Once the solid cores grew large enough, their gravity quickly attracted surrounding gas to become the massive planets we see today. Since that gas had lost some of its oxygen, the planet ends up with less oxygen and less water than if it had formed through a gravitational instability.”

There are two leading models of planetary formation: core accretion and gravitational instability. When stars form, a planet-forming disk surrounds them. With core accretion, planets form gradually as solid cores slowly grow big enough to start acquiring gas from the disk, while in the gravitational instability model, planets form almost instantly as the disk collapses on itself.

Properties such as the composition of a planet’s atmosphere are clues to how the planet formed, and in this case core accretion seems to win out. Although there was evidence of water vapor, that signature is weaker than would be expected if the planet shared the composition of its parent star. Instead, the planet has a high ratio of carbon to oxygen – a fingerprint of its formation in the gaseous disk tens of millions of years ago. As the gas cooled with time, grains of water ice formed, depleting the remaining gas of oxygen. Planetary formation then began when ice and solids collected into planetary cores.

“Once the solid cores grew large enough, their gravity quickly attracted surrounding gas to become the massive planets we see today,” said Konopacky. “Since that gas had lost some of its oxygen, the planet ends up with less oxygen and less water than if it had formed through a gravitational instability.”

“Spectral information of this quality not only provides clues about the formation of the HR8799 planets but also provides the guidance we need to improve our theoretical understanding of exoplanet atmospheres and their early evolution,” said Barman. “The timing of this work could not be better as it comes on the heels of new instruments that will image dozens more exoplanets, orbiting other stars, that we can study in similar detail.”

This system was also the study as part of remote reconnaissance imaging with Project 1640. The video below explains more:

Source: Keck Observatory

Evidence for a Deep Ocean on Europa Might be Found on its Surface

Astronomer Mike Brown and his colleague Kevin Hand might be suffering from “Pump Handle Phobia,” as radio personality Garrison Keillor calls it, where those afflicted just can’t resist putting their tongues on something frozen to see if it will stick. But Brown and Hand are doing it all in the name of science, and they may have found the best evidence yet that Europa has a liquid water ocean beneath its icy surface. Better yet, that vast subsurface ocean may actually shoot up to Europa’s surface, on occasion.

In a recent blog post, Brown pondered what it would taste like if he could lick the icy surface of Jupiter’s moon Europa. “The answer may be that it would taste a lot like that last mouthful of water that you accidentally drank when you were swimming at the beach on your last vacation. Just don’t take too long of a taste. At nearly 300 degrees (F) below zero your tongue will stick fast.”

His ponderings were based on a new paper by Brown and Hand which combined data from the Galileo mission (1989 to 2003) to study Jupiter and its moons, along with new spectroscopy data from the 10-meter Keck II telescope in Hawaii.

The study suggests there is a chemical exchange between the ocean and surface, making the ocean a richer chemical environment.

“We now have evidence that Europa’s ocean is not isolated—that the ocean and the surface talk to each other and exchange chemicals,” said Brown, who is an astronomer and professor of planetary astronomy at Caltech. “That means that energy might be going into the ocean, which is important in terms of the possibilities for life there. It also means that if you’d like to know what’s in the ocean, you can just go to the surface and scrape some off.”

“The surface ice is providing us a window into that potentially habitable ocean below,” said Hand, deputy chief scientist for solar system exploration at JPL.

Europa’s ocean is thought to cover the moon’s whole globe and is about 100 kilometers (60 miles) thick under a thin ice shell. Since the days of NASA’s Voyager and Galileo missions, scientists have debated the composition of Europa’s surface.

Salts were detected in the Galileo data – “Not ‘salt’ as in the sodium chloride of your table salt,” Brown wrote in his blog, “Mike Brown’s Planets,” “but more generically ‘salts’ as in ‘things that dissolve in water and stick around when the water evaporates.’”

That idea was enticing, Brown said, because if the surface is covered by things that dissolve in water, that strongly implies that Europa’s ocean water has flowed on the surface, evaporated, and left behind salts.

But there were other explanations for the Galileo data, as Europa is constantly bombarded by sulfur from the volcanoes on Io, and the spectrograph that was on the Galileo spacecraft wasn’t able to tell the difference between salts and sulfuric acid.

But now, with data from the Keck Observatory, Brown and Hand have identified a spectroscopic feature on Europa’s surface that indicates the presence of a magnesium sulfate salt, a mineral called epsomite, that could have formed by oxidation of a mineral likely originating from the ocean below.

This view of Jupiter's moon Europa features several regional-resolution mosaics overlaid on a lower resolution global view for context. The regional views were obtained during several different flybys of the moon by NASA's Galileo mission.  Image credit: NASA/JPL-Caltech/University of Arizona.
This view of Jupiter’s moon Europa features several regional-resolution mosaics overlaid on a lower resolution global view for context. The regional views were obtained during several different flybys of the moon by NASA’s Galileo mission. Image credit: NASA/JPL-Caltech/University of Arizona.

Brown and Hand started by mapping the distribution of pure water ice versus anything else. The spectra showed that even Europa’s leading hemisphere contains significant amounts of non-water ice. Then, at low latitudes on the trailing hemisphere — the area with the greatest concentration of the non-water ice material — they found a tiny, never-before-detected dip in the spectrum.

The two researchers tested everything from sodium chloride to Drano in Hand’s lab at JPL, where he tries to simulate the environments found on various icy worlds. At the end of the day, the signature of magnesium sulfate persisted.

The magnesium sulfate appears to be generated by the irradiation of sulfur ejected from the Jovian moon Io and, the authors deduce, magnesium chloride salt originating from Europa’s ocean. Chlorides such as sodium and potassium chlorides, which are expected to be on the Europa surface, are in general not detectable because they have no clear infrared spectral features. But magnesium sulfate is detectable. The authors believe the composition of Europa’s ocean may closely resemble the salty ocean of Earth.

While no one is going to be traveling to Europa to lick its surface, for now, astronomers will continue to use the modern giant telescopes on Earth to continue to “take spectral fingerprints of increasing detail to finally understand the mysterious details of the salty ocean beneath the ice shell of Europa,” Brown said.

Also, NASA is looking into options to explore Europa further. (Universe Today likes the idea of a big drill or submarine!)

But in the meantime what happens next? “We look for chlorine, I think,” Brown wrote. “The existence of chlorine as one of the main components of the non-water-ice surface of Europa is the strongest prediction that this hypothesis makes. We have some ideas on how we might look; we’re working on them now. Stay tuned.”

Read Brown & Hand’s paper.

Sources: Mike Brown’s Planets, Keck Observatory, JPL

Rare Supernova Pair are Most Distant Ever

High-resolution simulation of a galaxy hosting a super-luminous supernova and its chaotic environment in the early Universe. Credit: Adrian Malec and Marie Martig (Swinburne University)

Some of the earliest stars were massive and short-lived, destined to end their lives in huge explosions. Astronomers have detected some of the earliest and most distant of these exploding stars, called ‘super-luminous’ supernovae — stellar explosions 10–100 times brighter than other supernova types. The duo sets a record for the most distant supernova yet detected, and offers clues about the very early Universe.

“The light of these supernovae contains detailed information about the infancy of the Universe, at a time when some of the first stars are still condensing out of the hydrogen and helium formed by the Big Bang,” said Dr. Jeffrey Cooke, an astrophysicist from Swinburne University of Technology in Australia, whose team made the discovery.

The team used a combination of data from the Canada-France-Hawaii Telescope and the Keck 1 Telescope, both located in Hawaii.

“The type of supernovae we’ve found are extremely rare,” Cooke said. “In fact, only one has been discovered prior to our work. This particular type of supernova results from the death of a very massive star (about 100 – 250 times the mass of our Sun) and explodes in a completely different way compared to other supernovae. Discovering and studying these events provides us with observational examples to better understand them and the chemicals they eject into the Universe when they die.”

Super-luminous supernovae were discovered only a few years ago, and are rare in the nearby Universe. Their origins are not well understood, but a small subset of them are thought to occur when extremely massive stars, 150 to 250 times more massive than our Sun, undergo a nuclear explosion triggered by the conversion of photons into electron-positron pairs. This process is completely different compared to all other types of supernovae. Such events are expected to have occurred more frequently in the early Universe, when massive stars were more common.

This, and the extreme brightness of these events, encouraged Cooke and colleagues to search for super-luminous supernovae at redshifts, z, greater than 2, when the Universe was less than one-quarter of its present age.

“We used LRIS (Low Resolution Imaging Spectrometer) on Keck I to get the deep spectroscopy to confirm the host redshifts and to search for late-time emission from the supernovae,” Cooke said. “The initial detections were found in the CFHT Legacy Survey Deep fields. The light from the supernovae arrived here on Earth 4 to 6 years ago. To confirm their distances, we need to get a spectrum of their host galaxies which are very faint because of their extreme distance. The large aperture of Keck and the high sensitivity of LRIS made this possible. In addition, some supernovae have bright enough emission features that persist for years after they explode. The deep Keck spectroscopy is able to detect these lines as a further means of confirmation and study.”

Cooke and co-workers searched through a large volume of the Universe at z greater than or equal to 2, and found two super-luminous supernovae, at redshifts of 2.05 and 3.90 — breaking the previous supernova redshift record of 2.36, and implying a production rate of super-luminous supernovae at these redshifts at least 10 times higher than in the nearby Universe. Although the spectra of these two objects make it unlikely that their progenitors were among the first generation of stars, the present results suggest that detection of those stars may not be far from our grasp.

Detecting the first stars allows us much greater understanding of the first stars in the Universe, Cooke said.

“Shortly after the Big Bang, there was only hydrogen and helium in the Universe,” he said. “All the other elements that we see around us today, such as carbon, oxygen, iron, and silicon, were manufactured in the cores of stars or during supernova explosions. The first stars to form after the Big Bang laid the framework for the long process of enriching the Universe that eventually produced the diverse set of galaxies, stars, and planets we see around us today. Our discoveries probe an early time in the Universe that overlaps with the time we expect to see the first stars.”

Sources: Keck Observatory, Nature

Uranus has Bizarre Weather

New infrared images of Uranus show details not seen before. Credit: NASA/ESA/L. A. Sromovsky/P. M. Fry/H. B. Hammel/I. de Pater/K. A. Rages

Here’s the scene: a thick, tempestuous atmosphere with winds blowing at a clip of 900 km/h (560 mph); massive storms that would engulf continents here on Earth, and temperatures in the -220 C (-360 degree F) range. Sounds like a cold Hell, but this is the picture emerging of the planet Uranus, revealed in new high-resolution infrared images from the Keck Observatory in Hawaii, exposing in incredible detail the bizarre weather of a planet that was once thought to be rather placid.

“My first reaction to these images was ‘wow’ and then my second reaction was ‘WOW,'” said Heidi Hammel, a co-investigator on the new observations. “These images reveal an astonishing amount of complexity in Uranus’ atmosphere. We knew the planet was active, but until now much of the activity was masked by noise in our data.”

Voyager 2’s view of Uranus. Credit: NASA

With its beautiful blue atmosphere, Uranus can seem rather tranquil at first glance. Even the flyby of Voyager 2 in 1986 revealed a rather “bland” blue ball. But coming into focus now with the new are large weather systems, and even though they are probably much less violent than storms on Earth, the weather on Uranus is just…bizarre.

“Some of these weather systems,” said Larry Sromovsky, from the University of Wisconsin-Madison who led the new study using the Keck II telescope, “stay at fixed latitudes and undergo large variations in activity. Others are seen to drift toward the planet’s equator while undergoing great changes in size and shape. Better measures of the wind fields that surround these massive weather systems are the key to unraveling their mysteries.”

Sromovsky, Hammel and their colleagues are using new infrared techniques to deliver some of the “most richly detailed views of Uranus yet obtained by any instrument on any observatory. No other telescope could come close to producing this result,” Sromovsky said.

What they are seeing are previously undetected, small but widely distributed weather feature, and they hope the movements of these features can help make sense of the planet’s odd pattern of winds.

They observed a scalloped band of clouds just south of Uranus’ equator and a swarm of small convective features in the north polar regions of the planet. Features like this don’t seem to be in the southern polar regions, but are similar to the types of “popcorn” –type clouds seen on Saturn. Uranus’ north pole is not visible from Earth night now, but when it does come into view, the researchers wouldn’t be surprised to see a polar vortex feature similar to what has been seen at Saturn’s south pole.

The driver of these features must be solar energy because there is no other detectable internal energy source.

“But the Sun is 900 times weaker there than on Earth because it is 30 times further from the Sun, so you don’t have the same intensity of solar energy driving the system,” said Sromovsky. “Thus the atmosphere of Uranus must operate as a very efficient machine with very little dissipation. Yet the weather variations we see seem to defy that requirement.”

One possible explanation, is that methane is pushed north by an atmospheric conveyor belt toward the pole where it wells up to form the convective features visible in the new images. The phenomena may be seasonal, the team said, but they are still working on trying to put together a clear seasonal trend in the winds of Uranus.

“Uranus is changing,” he said, “and there is certainly something different going on in the two polar regions.”

The images were released at the American Astronomical Society’s Division for Planetary Sciences meeting taking place this week.

Source: University of Wisconsin-Madison

Behind the Scenes at the Keck Telescope

Who knew there were so many moving parts to operate a telescope? This is a great behind the scenes video of what really takes place up at the summit of Mauna Kea in Hawaii. About 125 people work full-time at the Keck Observatory to operate the two ten-meter telescopes. The intricate fine-tuning and elaborate attention to detail is amazing. “Keeping those telescopes on-sky every night is the summit crew of the Operations Department. This video is dedicated to the guys of the Keck daycrew who make it possible,” wrote Keck engineer Andrew Cooper, who compiled this unique and must-watch video. He details the techniques he used at his Vimeo page for this video.

Watch Live Webcast from the Keck Observatory

On Thursday, Feb. 9, 2012, Keck Observatory will be hosting a live webcast of an astronomy talk by Dr. Tom Soifer of Caltech, who is the Director of the Spitzer Science Center. The title of the talk is “Seeing the Invisible Universe,” and Soifer will discuss the latest exciting results from NASA’s Spitzer Space Telescope. The webcast begins at 7 pm Hawaiian Time, 9 pm Pacific Time (5 am GMT, Feb 10) and will be streamed from the Kahilu Theatre in Waimea-Kamuela, on the Big Island of Hawaii. Watch in the window above (click the play button) or watch on the Keck website.

Potential ‘Goldilocks’ Planet Found

A new-found planet is in a ‘just-right’ location around its star where liquid water could possibly exist on the planet’s surface. A team of international astronomers have discovered a potentially habitable super-Earth orbiting a nearby star in a habitable zone, where it isn’t too hot or too cold for liquid water to exist. The planet, GJ 667Cc, has an orbital period of about 28 days and with a mass about 4.5 times that of the Earth. The star that it orbits is quite interesting. It is an M-class dwarf star and is a member of a triple star system and appears to be quite different from our Sun, relatively lacking in metallic elements.

The team said this discovery demonstrates that habitable planets could form in a greater variety of environments than previously believed.

“This was expected to be a rather unlikely star to host planets,” said Steven Vogt from UC Santa Cruz, one of the scientists involved in the discovery. “Yet there they are, around a very nearby, metal-poor example of the most common type of star in our galaxy. The detection of this planet, this nearby and this soon, implies that our galaxy must be teeming with billions of potentially habitable rocky planets.”

“This planet is the new best candidate to support liquid water and, perhaps, life as we know it,” said Guillem Anglada-Escudé, from the University of Gottingen in Germany. He was with the Carnegie Institute for Science when the planet was first discovered.

The planet orbits quite close to its parent star at 0.12 astronomical units, which is much closer than Mercury to the Sun. However, the Planetary Habitability Laboratory says the star is much dimmer and provides enough energy for the planet to possibly maintain similar terrestrial temperatures. There’s a caveat, though, that astronomers aren’t sure what the planet’s composition is, because they have not been able to measure its size; therefore, it could be a either a rocky or a gas planet. I would need to have a radius between about 1.7 and 2.2 Earth radii to be a rocky world.

The team used public data from the European Southern Observatory combined with observations from the Keck Observatory in Hawaii and the new Carnegie Planet Finder Spectrograph at the Magellan II Telescope in Chile. To follow up and verify the findings, the team used the radial velocity method to measures the small wobbles in the star’s motion caused by the gravitational tug of a planet.

“With the advent of a new generation of instruments, researchers will be able to survey many M dwarf stars for similar planets and eventually look for spectroscopic signatures of life in one of these worlds,” said Anglada-Escudé.

The star, GJ 667C is 22 light years away. It has much lower abundance of elements heavier than helium, such as iron, carbon, and silicon, as does our Sun. The other two stars (GJ 667A and B) are a pair of orange K dwarfs, with a concentration of heavy elements only 25% that of our Sun’s. Such elements are the building blocks of terrestrial planets so it was thought to be unusual for metal-depleted star systems to have an abundance of low mass planets.

Diagram of the planets orbiting the star GJ 667C. Credit: UC Santa Cruz

GJ 667C had previously been observed to have another super-Earth (GJ 667Cb) with a period of 7.2 days, although this finding was never published. This orbit is too tight, and thus hot, to support life. The new study started with the aim of obtaining the orbital parameters of this super-Earth, and came to find an additional planet.

The new planet receives 90% of the light that Earth receives. However, because most of its incoming light is in the infrared, a higher percentage of this incoming energy should be absorbed by the planet. When both these effects are taken into account, the planet is expected to absorb about the same amount of energy from its star that the Earth absorbs from the Sun. This would allow surface temperatures similar to Earth and perhaps liquid water, but this extreme cannot be confirmed without further information on the planet’s atmosphere.

The team said there is a possibility of other planets in the system, potentially a gas-giant planet and an additional super-Earth with an orbital period of 75 days. However, further observations are needed to confirm these two possibilities.

This is the fourth potentially habitiable extrasolar planet. Three were found in 2011: Gliese 581d, which scientists say is likely a rocky world about 20 ight-years away; HD 85512 b, another planet orbiting in a habitable zone is about 36 light-years away from Earth; and Kepler 22b, about 600 light-years away. Vogt was involved in the discovery of another planet in 2010 (Gliese 581g) in which he said the “chances of life on this planet are 100%,” but other astronomers have cast doubt on whether that planet even exists.

The HARPS search for southern extra-solar planets XXXI. The M-dwarf sample, and A planetary system around the nearby M dwarf GJ 667C with at least one super-Earth in its habitable zone (will add link when it becomes available)

Sources: UC Santa Cruz, Carnegie Institute for Science, Planetary Habitability Laboratory

A Star-Making Blob from the Cosmic Dawn


Looking back in time with some of our best telescopes, astronomers have found one of the most distant and oldest galaxies. The big surprise about this blob-shaped galaxy, named GN-108036, is how exceptionally bright it is, even though its light has taken 12.9 billion years to reach us. This means that back in its heyday – which astronomers estimate at about 750 million years after the Big Bang — it was generating an exceptionally large amount of stars in the “cosmic dawn,” the early days of the Universe.

“The high rate of star formation found for GN-108036 implies that it was rapidly building up its mass some 750 million years after the Big Bang, when the Universe was only about five percent of its present age,” said Bahram Mobasher, from the University of California, Riverside. “This was therefore a likely ancestor of massive and evolved galaxies seen today.”

An international team of astronomers, led by Masami Ouchi of the University of Tokyo, Japan, first identified the remote galaxy after scanning a large patch of sky with the Subaru Telescope atop Mauna Kea in Hawaii. Its great distance was then confirmed with the W.M. Keck Observatory, also on Mauna Kea. Then, infrared observations from the Spitzer and Hubble space telescopes were crucial for measuring the galaxy’s star-formation activity.

“We checked our results on three different occasions over two years, and each time confirmed the previous measurement,” said Yoshiaki Ono, also from the of the University of Tokyo.

Astronomers were surprised to see such a large burst of star formation because the galaxy is so small and from such an early cosmic era. Back when galaxies were first forming, in the first few hundreds of millions of years after the Big Bang, they were much smaller than they are today, having yet to bulk up in mass.

The team says the galaxy’s star production rate is equivalent to about 100 suns per year. For reference, our Milky Way galaxy is about five times larger and 100 times more massive than GN-108036, but makes roughly 30 times fewer stars per year.

Astronomers refer to the object’s distance by a number called its “redshift,” which relates to how much its light has stretched to longer, redder wavelengths due to the expansion of the universe. Objects with larger redshifts are farther away and are seen further back in time. GN-108036 has a redshift of 7.2. Only a handful of galaxies have confirmed redshifts greater than 7, and only two of these have been reported to be more distant than GN-108036.

About 380,000 years after the Big Bang, a decrease in the temperature of the Universe caused hydrogen atoms to permeate the cosmos and form a thick fog that was opaque to ultraviolet light, creating what astronomers call the cosmic dark ages.

“It ended when gas clouds of neutral hydrogen collapsed to generate stars, forming the first galaxies, which probably radiated high-energy photons and reionized the Universe,” Mobasher said. “Vigorous galaxies like GN-108036 may well have contributed to the reionization process, which is responsible for the transparency of the Universe today.”

“The discovery is surprising because previous surveys had not found galaxies this bright so early in the history of the universe,” said Mark Dickinson of the National Optical Astronomy Observatory in Tucson, Ariz. “Perhaps those surveys were just too small to find galaxies like GN-108036. It may be a special, rare object that we just happened to catch during an extreme burst of star formation.”

Sources: Science Paper by: Y. Ono et al., Subaru , Spitzer Hubble