Friday, January 9, 2015

Disorderly Conduct: Andromeda’s Mature Stars Exhibit Surprising Behavior, Says Study

Disorderly Conduct: Andromeda’s Mature Stars Exhibit Surprising Behavior, Says Study:



The Andromeda Galaxy will collide with the Milky Way in the future. Credit: Adam Evans


The Andromeda Galaxy is now believed to consist of multiple generations of stars, with younger stars behaving in a far more well-ordered fashion than their older counterparts. Image credit: Adam Evans
To a distant observer, our own Milky Way and the Andromeda galaxy would probably look very similar. Although Andromeda is longer, more massive, and more luminous than the Milky Way, both galaxies are vast spirals composed of hundreds of millions of stars. But new research presented at this week’s AAS conference in Seattle suggests that there are other differences as well – namely, in the movement and behavior of certain stellar age groups. This observation is the first of its kind, and raises new questions about the factors that contribute to the formation of spiral galaxies like our own.

Armed with data from both the Hubble Space Telescope and the Keck Observatory in Hawaii, a group of astronomers from UC Santa Cruz resolved 10,000 tiny points of light in the Andromeda galaxy into individual stars and used their spectra to calculate the stars’ ages and velocities – a feat never before accomplished for a galaxy outside of our own.

Led by Puragra Guhathakurta, a professor of astrophysics, and Claire Dorman, a graduate student, the researchers found that in Andromeda, the behavior of older stars is surprisingly more frazzled than that of their younger counterparts; that is, they have a much wider range of velocities around the galactic center. Meanwhile, in the Milky Way, stars of all ages seem to coexist far more peacefully, moving along at the same speed in a consistent, ordered pack.

The astronomers believe that this asymmetry causes Andromeda to look more distinct from our own galaxy than previously thought. “If you could look at [Andromeda’s] disk edge on, the stars in the well-ordered, coherent population would lie in a very thin plane, whereas the stars in the disordered population would form a much puffier layer,” said Dorman.

What could account for such disorderly conduct among Andromeda’s older generation? It is possible that these more mature stars could have been disturbed long ago, during episodes of the kind of “galactic cannibalism” that is thought to go on among most spiral galaxies. Indeed, trails of stars in its outer halo suggest that Andromeda has collided with and consumed a number of smaller galaxies over the course of its lifetime; however, these effects cannot completely account for the jumbled flow of Andromeda’s most elderly stars.



A few examples of merging galaxies. NASA, ESA, the Hubble Heritage Team (STScI/AURA)-ESA/Hubble Collaboration and A. Evans (University of Virginia, Charlottesville/NRAO/Stony Brook University), K. Noll (STScI), and J. Westphal (Caltech)


A few examples of galactic cannibalism. NASA, ESA, the Hubble Heritage Team (STScI/AURA)-ESA/Hubble Collaboration and A. Evans (University of Virginia, Charlottesville/NRAO/Stony Brook University), K. Noll (STScI), and J. Westphal (Caltech)
Astronomers believe that a second explanation could fill in the blanks – one that owes to events occurring far earlier in history, during the birth of the galaxy itself. After all, if Andromeda originated from a lumpy, irregular gas cloud, its oldest stars would naturally appear fairly disordered. Over time, the parent gas would have settled down, giving rise to ever more organized generations of stars.

Guhathakurta, Dorman, and the rest of the team hope that their work will encourage other scientists to create simulations that will better constrain these possibilities. To them, understanding Andromeda is a vital key to learning more about our own galaxy. Guhathakurta explained, “In the Andromeda galaxy we have the unique combination of a global yet detailed view of a galaxy similar to our own. We have lots of detail in our own Milky Way, but not the global, external perspective.”

Now, thanks to this new research, scientists can cite our own galaxy’s comparative orderliness as strong evidence that we live in a quieter, less cannibalistic neighborhood than most other spiral galaxies in the Universe. “Even the most well ordered Andromeda stars are not as well ordered as the stars in the Milky Way’s disk,” said Dorman.

At least until 4 billion years from now, when the Milky Way and Andromeda collide.

We may as well enjoy the A+ for conduct while we can.



About 

Vanessa earned her bachelor's degree in Astronomy and Physics in 2009 from Wheaton College in Massachusetts. Her credits in astronomy include observing and analyzing eclipsing binary star systems and taking a walk on the theory side as a NSF REU intern, investigating the expansion of the Universe by analyzing its traces in observations of type 1a supernovae. In her spare time she enjoys writing about astrophysics, cosmology, biology, and medicine, making delicious vegetarian meals, taking adventures with her husband and/or Nikon D50, and saving the world.
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If You Can Find Orion, You Can Find Comet Lovejoy

If You Can Find Orion, You Can Find Comet Lovejoy:



The constellation Orion and Comet Lovejoy (C/2014 Q2), highlighted for easy viewing, as seen from Millersville, Maryland on January 7, 2015. Credit and copyright: Brian Moran.


The constellation Orion and Comet Lovejoy (C/2014 Q2), highlighted for easy viewing, as seen from Millersville, Maryland on January 7, 2015. Credit and copyright: Brian Moran.
Comet Lovejoy (2014 Q2) is now visible in the night sky, and while you’ll need binoculars or a low-power telescope to see it best, the perfect window of opportunity to see it for yourself is starting now! We’ve heard from some readers that they’ve had some trouble spying it, but photographer Brian Moran has snapped the perfect picture to show you EXACTLY where to look for the comet. All you need to do is look for the easy-to-find constellation of Orion, and swing your eyes to the right (about 20 degrees) and up slightly up.

Brian said he was having trouble finding Lovejoy, but perhaps it may have been because he was looking a little too close to Orion. “Orion is a great frame of reference, but all of the photos I saw online made it seem like it was closer to Orion than it actually is,” he said.

Comet Q2 Lovejoy is currently shining at 4th magnitude, and if you’ve got a really dark sky, you may be able to see it with the unaided eye. as our David Dickinson explained, this comet is now entering “prime time” evening sky viewing, as it is visible over the southern horizon at around 9:30 PM local time this weekend, then 8:00 PM on January the 15th, and just before 6:00 PM by January 31st.

Tonight (Thursday, January 8) we’ll have a “two-hour window of darkness between the end of twilight and moonrise for those of us in the world’s mid-northern latitudes. Each night after tonight the Moon rises nearly an hour later,” said Sky & Telescope’s Alan MacRobert.



Finder chart for Comet Lovejoy, C/2014 Q2, during January 2015. The dates are in Universal Time; the ticks are at 0:00 UT (7:00 p.m. on the previous date Eastern Standard Time). Click on the image for larger, print-friendly black-on-white PDF, courtesy of Sky & Telescope.


Finder chart for Comet Lovejoy, C/2014 Q2, during January 2015. The dates are in Universal Time; the ticks are at 0:00 UT (7:00 p.m. on the previous date Eastern Standard Time). Click on the image for larger, print-friendly black-on-white PDF, courtesy of Sky & Telescope.
While C/Q2 Lovejoy passed closest to Earth yesterday (January 7) at a distance of 0.47 a.u. (44 million miles; 70 million km), the comet should remain at about the same brightness as it crosses the sky into Taurus, Aries, and Triangulum, higher and higher in early evening. It will pass 8° west-southwest of the Pleiades on the evening of January 17th.

MacRobert also explained that although the comet is beginning to recede from us, its intrinsic brightness should still be increasing a bit. “That’s because it doesn’t reach perihelion (its closest to the Sun) until January 30th (at a rather distant 1.29 a.u. from the Sun),” he said. “By that date the comet should finally be fading slightly from Earth’s point of view. And in late January the Moon returns; it’s first-quarter on the 26th.”

Here are some great images of Comet Lovejoy taken by Universe Today readers. Be sure to check out our Flickr group for more great images! We have nearly 1,500 members and new photos are added every day. And if you take an astrophoto, join our group and submit your photos! We may use your image in an upcoming article!



A wide-angle shot of Comet Lovejoy 2014 Q2 above snow-covered trees. Taken as it neared Orion on January 6, 2014. Credit and copyright: Marion Haligowski.


A wide-angle shot of Comet Lovejoy 2014 Q2 above snow-covered trees. Taken as it neared Orion on January 6, 2014. Credit and copyright: Marion Haligowski.


C/2014 Q2 Lovejoy on 7th January 2015. A couple of satellites managed to sneak in the image, too! Credit and copyright: JP Willinghan.


C/2014 Q2 Lovejoy on 7th January 2015. A couple of satellites managed to sneak in the image, too! Credit and copyright: JP Willinghan.


Comet C/2014 Q2 Lovejoy Passes Messier 79 Narrowfield C False Color, taken on Dec 29, 2014, from New Mexico Skies using a 43-cm CDK telescope and STXL-6303 camera on a PME II mount. Credit and copyright: Joseph Brimacombe.


Comet C/2014 Q2 Lovejoy Passes Messier 79 Narrowfield C False Color, taken on Dec 29, 2014, from New Mexico Skies using a 43-cm CDK telescope and STXL-6303 camera on a PME II mount. Credit and copyright: Joseph Brimacombe.


A monochrome image of Comet Lovejoy (2014 Q2) taken on December 31, 2014. Credit and copyright: Damian Peach.


A monochrome image of Comet Lovejoy (2014 Q2) taken on December 31, 2014. Credit and copyright: Damian Peach.


Comet Lovejoy, as seen on December 29, 2014 at around 12.30AM SGT from Singapore. Also visible is spiral galaxy NGC1886, seen to the left of the coma. Total exposure time is 12 minutes. Credit and copyright: Justin Ng.


Comet Lovejoy, as seen on December 29, 2014 at around 12.30AM SGT from Singapore. Also visible is spiral galaxy NGC1886, seen to the left of the coma. Total exposure time is 12 minutes. Credit and copyright: Justin Ng.


Comet Lovejoy as seen from Aldalucia, Spain on December 30, 2013. Credit and copyright: Ian Sharp.


Comet Lovejoy as seen from Aldalucia, Spain on December 30, 2013. Credit and copyright: Ian Sharp.


Comet Lovejoy Passing Globular Cluster M-79. Credit and copyright: Greg Redfern.


Comet Lovejoy Passing Globular Cluster M-79. Credit and copyright: Greg Redfern.
A two-part panorama of Comet 2014 Q2 Lovejoy as seen from Payson, Arizona on December 27, 2014. Credit and copyright: Chris Schur
A two-part panorama of Comet 2014 Q2 Lovejoy as seen from Payson, Arizona on December 27, 2014. Credit and copyright: Chris Schur
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How NASA Is Saving Fuel On Its Outer Solar System Missions

How NASA Is Saving Fuel On Its Outer Solar System Missions:



Saturn. Image Credit: NASA/JPL/SSI


Saturn. Image Credit: NASA/JPL/SSI
While Saturn is far away from us, scientists have just found a way to make the journey there easier. A new technique pinpointed the position of the ringed gas giant to within just two miles (four kilometers).

It’s an impressive technological feat that will improve spacecraft navigation and also help us better understand the orbits of the outer planets, the Jet Propulsion Laboratory (JPL) said.

It’s remarkable how much there is to learn about Saturn’s position given that the ancients discovered it, and it’s easily visible with the naked eye. That said, the new measurements with the Cassini  spacecraft and the Very Long Baseline Array radio telescope array are 50 times more precise than previous measurements with telescopes on the ground.

“This work is a great step toward tying together our understanding of the orbits of the outer planets of our solar system and those of the inner planets,” stated study leader Dayton Jones of JPL.



Saturn and its rings, as seen from above the planet by the Cassini spacecraft. Credit: NASA/JPL/Space Science Institute. Assembled by Gordan Ugarkovic.


Saturn and its rings, as seen from above the planet by the Cassini spacecraft. Credit: NASA/JPL/Space Science Institute/Gordan Ugarkovic
What’s even more interesting is scientists have been using the better information as it comes in. Cassini began using the improved method in 2013 to improve its precision when it fires its engines.

This, in the long term, leads to fuel savings — allowing the spacecraft a better chance of surviving through the end of its latest mission extension, which currently is 2017. (It’s been orbiting Saturn since 2004.)

The technique is so successful that NASA plans to use the same method for the Juno spacecraft, which is en route to Jupiter for a 2016 arrival.



Juno will repeatedly dive between the planet and its intense belts of charged particle radiation, coming only 5,000 kilometers (about 3,000 miles) from the cloud tops at closest approach. (NASA/JPL-Caltech)


Juno will repeatedly dive between the planet and its intense belts of charged particle radiation, coming only 5,000 kilometers (about 3,000 miles) from the cloud tops at closest approach. (NASA/JPL-Caltech)
Scientists are excited about Cassini’s mission right now because it is allowing them to observe the planet and its moons as it reaches the summer solstice of its 29-year orbit.

This could, for example, provide information on how the climate of the moon Titan changes — particularly with regard to its atmosphere and ethane/methane-riddled seas, both believed to be huge influencers for the moon’s temperature.

Beyond the practical applications, the improved measurements of Saturn and Cassini’s position are also giving scientists more insight into Albert Einstein’s theory of general relatively, JPL stated. They are taking the same techniques and applying them to observing quasars — black-hole powered galaxies — when Saturn passes in front of them from the viewpoint of Earth.

Source: Jet Propulsion Laboratory



About 

Elizabeth Howell is the senior writer at Universe Today. She also works for Space.com, Space Exploration Network, the NASA Lunar Science Institute, NASA Astrobiology Magazine and LiveScience, among others. Career highlights include watching three shuttle launches, and going on a two-week simulated Mars expedition in rural Utah. You can follow her on Twitter @howellspace or contact her at her website.
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Wednesday, January 7, 2015

Exoplanet-Hunting TESS Satellite to be Launched by SpaceX

Exoplanet-Hunting TESS Satellite to be Launched by SpaceX:



A conceptual image of the Transiting Exoplanet Survey Satellite. Image Credit: MIT


A conceptual image of the Transiting Exoplanet Survey Satellite.
Image Credit: MIT
The search for exoplanets is heating up, thanks to the deployment of space telescopes like Kepler and the development of new observation methods. In fact, over 1800 exoplanets have been discovered since the 1980s, with 850 discovered just last year. That’s quite the rate of progress, and Earth’s scientists have no intention of slowing down!

Hot on the heels of the Kepler mission and the ESA’s deployment of the Gaia space observatory last year, NASA is getting ready to launch TESS (the Transiting Exoplanet Survey Satellite). And to provide the launch services, NASA has turned to one of its favorite commercial space service providers – SpaceX.

The launch will take place in August 2017 from the Cape Canaveral Air Force Station in Florida, where it will be placed aboard a Falcon 9 v1.1 – a heavier version of the v 1.0 developed in 2013. Although NASA has contracted SpaceX to perform multiple cargo deliveries to the International Space Station, this will be only the second time that SpaceX has assisted the agency with the launch of a science satellite.

This past September, NASA also signed a lucrative contract with SpaceX worth $2.6 billion to fly astronauts and cargo to the International Space Station. As part of the Commercial Crew Program, SpaceX’s Falcon 9 and Dragon spacecraft were selected by NASA to help restore indigenous launch capability to the US.



James Webb Space Telescope. Image credit: NASA/JPL


Artist’s impression of the James Webb Space Telescope, the space observatory scheduled for launch in 2018. Image Credit: NASA/JPL
The total cost for TESS is estimated at approximately $87 million, which will include launch services, payload integration, and tracking and maintenance of the spacecraft throughout the course of its three year mission.

As for the mission itself, that has been the focus of attention for many years. Since it was deployed in 2009, the Kepler spacecraft has yielded more and more data on distant planets, many of which are Earth-like and potentially habitable. But in 2013, two of four reaction wheels on Kepler failed and the telescope has lost its ability to precisely point toward stars. Even though it is now doing a modified mission to hunt for exoplanets, NASA and exoplanet enthusiasts have been excited by the prospect of sending up another exoplanet hunter, one which is even more ideally suited to the task.

Once deployed, TESS will spend the next three years scanning the nearest and brightest stars in our galaxy, looking for possible signs of transiting exoplanets. This will involve scanning nearby stars for what is known as a “light curve”, a phenomenon where the visual brightness of a star drops slightly due to the passage of a planet between the star and its observer.

By measuring the rate at which the star dims, scientists are able to estimate the size of the planet passing in front of it. Combined with measurements the star’s radial velocity, they are also able to determine the density and physical structure of the planet. Though it has some drawbacks, such as the fact that stars rarely pass directly in front of their host stars, it remains the most effective means of observing exoplanets to date.



Number of extrasolar planet discoveries per year through September 2014, with colors indicating method of detection: radial velocity transit timing direct imaging microlensing. Image Credit: Public domain


Number of extrasolar planet discoveries on up to Sept. 2014, with colors indicating method of detection. Blue: radial velocity; Green: transit; Yellow: timing, Red: direct imaging; Orange: microlensing. Image Credit: Alderon/Wikimedia Commons
In fact, as of 2014, this method became the most widely used for determining the presence of exoplanets beyond our Solar System. Compared to other methods – such as measuring a star’s radial velocity, direct imaging, the timing method, and microlensing – more planets have been detected using the transit method than all the other methods combined.

In addition to being able to spot planets by the comparatively simple method of measuring their light curve, the transit method also makes it possible to study the atmosphere of a transiting planet. Combined with the technique of measuring the parent star’s radial velocity, scientists are also able to measure a planet’s mass, density, and physical characteristics.

With TESS, it will be possible to study the mass, size, density and orbit of exoplanets. In the course of its three-year mission, TESS will be looking specifically for Earth-like and super-Earth candidates that exist within their parent star’s habitable zone.

This information will then be passed on to Earth-based telescopes and the James Webb Space Telescope – which will be launched in 2018 by NASA with assistance from the European and Canadian Space Agencies – for detailed characterization.

The TESS Mission is led by the Massachusetts Institute of Technology – who developed it with seed funding from Google – and is overseen by the Explorers Program at NASA’s Goddard Space Flight Center in Greenbelt, Maryland.

Further Reading: NASA, SpaceX



About 

Author, freelance writer, educator, Taekwon-Do instructor, and loving hubby, son and Island boy!
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New Finds From Kepler: 8 New Worlds Discovered in the Habitable Zone

New Finds From Kepler: 8 New Worlds Discovered in the Habitable Zone:



An artist's conception of one of the newly released exo-worlds, a planet orbiting an ancient planetary nebula. Credit: David A. Aguilar/CfA.


An artist’s conception of one of the newly released exo-worlds, a planet orbiting an ancient planetary nebula. Credit: David A. Aguilar/CfA.
A fascinating set of finds was announced today at the 225th meeting of the American Astronomical Society (AAS), currently underway this week in Seattle, Washington. A team of astronomers announced the discovery of eight new planets potentially orbiting their host stars in their respective habitable zones. Also dubbed the ‘Goldilocks Zone,’ this is the distance where — like the tempting fairytale porridge — it’s not too hot, and not too cold, but juuusst right for liquid water to exist.

And chasing the water is the name of the game when it comes to hunting for life on other worlds. Two of the discoveries announced, Kepler-438b and Kepler-442b, are especially intriguing, as they are the most comparable to the Earth size-wise of any exoplanets yet discovered.

“Most of these planets have a good chance of being rocky, like Earth,” said Guillermo Torres in a recent press release. Guillermo is the lead author in the study for the Harvard-Smithsonian Center for Astrophysics (CfA).

This also doubles the count of suspected terrestrial exo-worlds — planets with less than twice the diameter of the Earth — inferred to orbit in the habitable zone of their host stars.

Fans on exoplanet science will remember the announcement of the first prospective Earth-like world orbiting in the habitable zone of its host star, Kepler-186f announced just last year.

The Kepler Space Telescope looks for planets used a technique known as the transit method. If a planet is orbiting its host star along our line of sight, a small but measurable dip in the star’s brightness occurs. This has advantages over the radial velocity technique because it allows researchers to pin down the hidden planet’s orbit and size much more precisely. The transit method is biased, however, to planets close in to its host which happen to lie along our solar system-bound line of sight. Kepler may miss most exo-worlds inclined out of its view, but it overcomes this by staring at thousands of stars.



Kepler launch


The launch of Kepler from the Cape in 2009. Credit: NASA/Kim Shiflett.
Launched in 2009, Kepler has wrapped up its primary phase of starring at a patch of sky along the plane of the Milky Way in the directions of the constellations of Cygnus, Lyra and Hercules, and is now in its extended K2 mission using the solar wind pressure as a 3rd ‘reaction wheel’ to carry out targeted searches along the ecliptic plane.

Both newly discovered worlds highlighted in today’s announcement orbit distant red dwarf stars. Kepler-438 b is estimated to be 12% larger in diameter than the Earth, and Kepler-442 b is estimated by the team to be 33% larger. These worlds have a 70% and 60% chance of being rocky, respectively. For comparison, Ice giant planet Uranus is 4 times the diameter of the Earth, and over 14 times more massive.



A comparison of the new exoplanet finds between Earth and Jupiter. Credit: NASA/Kepler.


A comparison of the new exoplanet finds between Earth and Jupiter. Credit: NASA/Kepler.
“We don’t know for sure whether any of the planets in our sample are truly habitable,” Said CfA co-researcher in the study David Kipping. All we can say is that they’re promising candidates.”

The idea of habitable worlds around red dwarf stars is a tantalizing one. These stars are fainter and cooler than our Sun, and 7.5% to 50% as massive. They also have two primary factors going for them: they’re the most common type of stars in the universe, and they have life spans measured in trillions of years, much longer than the current age of the universe. If life could go from muck to making microwave dinners here on Earth in just a few billion years, it’s had lots longer to do the same on worlds orbiting red dwarf stars.

There is, however, one catch: the habitable zone surrounding a red dwarf is much closer in to its host star, and any would-be planet is subject to frequent surface-sterilizing flares. Perhaps a world with a synchronous rotation might be spared this fate and feature a habitable hemisphere well inside the snow line permanently turned away from its host.

The team made these discoveries by sifting though Kepler’s preliminary finds that are termed KOI’s, or Kepler Objects of Interest. Though these potential discoveries were far too small to pin down their masses using the traditional method, the team employed a program named BLENDER to statically validate the finds. BLENDER has been employed before in concert with backup observations for extremely tiny exoplanet discoveries. Torres and Francois Fressin developed the BLENDER program, and it is currently run on the massive Pleiades supercomputer at NASA Ames.

It was also noted in today’s press conference that two KOIs awaiting validation — 5737.01 and 2194.03 — may also prove to be terrestrial worlds  orbiting Sun-like stars that are possibly similar in size to the Earth.



The proposed target regions for the Kepler K2 mission. Credit: NASA/Kepler.


The proposed target regions for the Kepler K2 mission. Credit: NASA/Kepler.
But don’t plan on building an interstellar ark and heading off to these newly found worlds just yet. Kepler-438b sits 470 light years from Earth, and Kepler-442b is even farther away at 1,100 light years. And we’ll also add our usual caveat and caution that, from a distance, the planet Venus in our own solar system might look like a tempting vacation spot. (Spoiler alert: it’s not).

Still, these discoveries are fascinating finds and add to the growing menagerie of exoplanet systems. These will also serve as great follow up targets for TESS, Gaia and LSST survey, all set to add to our exoplanet knowledge in the coming decade.



The LSST mirror in the Tuscon Mirror Lab. (Photo by author).


The LSST mirror in the Tuscon Mirror Lab. (Photo by author).
And to think, I remember growing up as a child of the 1970s reading that exoplanet detections were soooo difficult that they might never occur in our lifetime… now, fast-forward to 2015, and we’re beginning to classify and characterize other brave new solar systems in the modern Age of Exoplanet Science.

-Looking to observe red dwarf stars with your backyard scope? Check out our handy list.



About 

David Dickinson is an Earth science teacher, freelance science writer, retired USAF veteran & backyard astronomer. He currently writes and ponders the universe from Tampa Bay, Florida.
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Kepler Targets Supermassive Black Hole

Kepler Targets Supermassive Black Hole:



Image Credit: NASA/Dana Berry/SkyWorks Digital


An artist’s conception of an active galactic nuclei. Image Credit: NASA / Dana Berry / SkyWorks Digital
With only an introductory course in science, it’s easy to think that scientists strictly follow the scientific method. They propose a new hypothesis, test that hypothesis, and after many years of hard work, either confirm or reject it. But science is often prone to chance. And when a surprise presents itself, the book titled “Scientific Method 101” often gets dropped in the trash. In short, science needs — and perhaps thrives on — stupid luck.

Take any scientific mission. Often designed to do one thing, a mission tends to open up a remarkable window on something unexpected. Now, NASA’s Kepler space telescope, designed to hunt for planets in our own galaxy, has helped measure an object much more distant and more massive than any of its detected planets: a black hole.

KA1858+4850 is a Seyfert galaxy with an active supermassive black hole feeding on nearby gas. It lies between the constellations Cygnus and Lyra approximately 100 million light-years away.

In 2012, Kepler provided a highly accurate light curve of the galaxy. But the team, led by Liuyi Pei from the University of California, Irvine, also relied on ground-based observations to compliment the Kepler data.

The trick is to look at how the galaxy’s light varies over time. The light first emitted from the accretion disk travels some distance before reaching a gas cloud, where it’s absorbed and re-emitted a short time later.

Measuring the time-delay between the two emitted points of light tells the size of the gap between the accretion disk and the gas cloud. And measuring the width of the emitted light from the gas cloud tells the velocity of the gas moving near the black hole (due to an effect known as Doppler broadening). Together, these two measurements allow astronomers to determine the mass of the supermassive black hole.

Pei and his colleagues measured a time delay of roughly 13 days, and a velocity of 770 kilometers per second. This allowed them to calculate a central black hole mass of roughly 8.06 million times the mass of the Sun.

The results have been published in the Astrophysical Journal and are available online.



About 

Shannon Hall is a freelance science journalist. She holds two B.A.'s from Whitman College in physics-astronomy and philosophy, and an M.S. in astronomy from the University of Wyoming. Currently, she is working toward a second M.S. from NYU's Science, Health and Environmental Reporting program. You can follow her on Twitter @ShannonWHall.
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Prying Planets Out of The Shadows: The Gemini Planet Imager’s First Year of Light

Prying Planets Out of The Shadows: The Gemini Planet Imager’s First Year of Light:



Image credit: Marshall Perrin (Space Telescope Science Institute), Gaspard Duchene (UC Berkeley), Max Millar-Blanchaer (University of Toronto), and the GPI Team.


The disk around HR 4796A. Image credit: Marshall Perrin (Space Telescope Science Institute) / Gaspard Duchene (UC Berkeley) / Max Millar-Blanchaer (University of Toronto) / the GPI Team.
This year marks the 20th anniversary of 51 Peg b, the first exoplanet detected around a Sun-like star. And although the number of sheer detections in the years since have been remarkable, it’s also remarkable how little we still know about these alien worlds, save for their distances from their host stars, their radii, and sometimes their masses.

But the ability to directly image these worlds provides the opportunity to change all that. “It’s the tip of the iceberg,” said Marshall Perrin from the Space Telescope Science Institute in a press conference at the American Astronomical Society’s meeting earlier today. “In the long run, we think that imaging offers perhaps the best path to characterizing rocky planets on Earth-like orbits.”

Perrin highlighted two intriguing results from the Gemini Planet Imager (GPI), an instrument designed not only to resolve the dim light of an exoplanet, but also analyze a planet’s atmospheric temperature and composition.

HR 8799

The first system observed with GPI was the well-known HR 8799 system, a large star orbited by four planets, located 130 light-years away. Previously, the Keck telescope had measured the atmosphere of one of the planets, HR 8799c, in six hours of observing time. But GPI matched that in only a half hour of telescope time and in less-than-ideal weather too. So the team quickly turned to the planet’s twin, HR 8799d.



Image credit: Patrick Ingraham (Stanford University), Mark Marley (NASA Ames), Didier Saumon (Los Alamos National Laboratory) and the GPI Team.


The spectra of planets HR 8799c and HR 8799d. Image credit: Patrick Ingraham (Stanford University) / Mark Marley (NASA Ames) / Didier Saumon (Los Alamos National Laboratory) / the GPI Team.
“What we found really surprised us,” said Perrin. “These two planets have been known to have the same brightness and the same broadband colors. But looking at their spectra, they’re surprisingly different.”

Perrin and his colleagues think the likely culprit is clouds. It’s possible that one planet has a uniform cloud cover, whereas the other planet has a more patchy cloud cover, allowing astronomers to see deeper into the atmosphere. Perrin, however, cautions that this explanation is still under interpretation.

“The fact that GPI was able to extract new knowledge from these planets on the first commissioning run in such a short amount of time, and in conditions that it was not even designed to work, is a real testament to how revolutionary GPI will be to the field of exoplanets,” said GPI team member Patrick Ingraham from Stanford University in a news release.

HR 4796A

Perrin’s presentation also introduced never-seen details in the dusty ring around the young star HR 4796A. GPI also has the unique ability of detecting only polarized light, which sheds light on different physical properties.

Although the details are fairly technical, “the short version is that reconciling the patterns we see in polarized intensity and in total intensity has forced us to think of this not as a very diffuse disk but one that is actually dense enough to partially opaque,” said Perrin.

The disk may be roughly analogous to one of Saturn’s rings.

“GPI now is moving into an exciting phase of full operations,” said Perrin, concluding his talk. “We’ll be opening up a lot of new discoveries hopefully over the next few years. And in the long run taking these technologies and scaling them to future 30-meter telescopes, and perhaps large telescopes in space, to continue direct imaging and push down toward the Earth-like planet regime.”



About 

Shannon Hall is a freelance science journalist. She holds two B.A.'s from Whitman College in physics-astronomy and philosophy, and an M.S. in astronomy from the University of Wyoming. Currently, she is working toward a second M.S. from NYU's Science, Health and Environmental Reporting program. You can follow her on Twitter @ShannonWHall.
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Hearing the Early Universe’s Scream: Sloan Survey Announces New Findings

Hearing the Early Universe’s Scream: Sloan Survey Announces New Findings:



A still photo from an animated flythrough of the universe using SDSS data. This image shows our Milky Way Galaxy. The galaxy shape is an artist’s conception, and each of the small white dots is one of the hundreds of thousands of stars as seen by the SDSS. Image credit: Dana Berry / SkyWorks Digital, Inc. and Jonathan Bird (Vanderbilt University)


A still photo from an animated flythrough of the universe using SDSS data. This image shows our Milky Way Galaxy. The galaxy shape is an artist’s conception, and each of the small white dots is one of the hundreds of thousands of stars as seen by the SDSS. Image credit:
Dana Berry / SkyWorks Digital, Inc. and Jonathan Bird (Vanderbilt University)
Imagine a single mission that would allow you to explore the Milky Way and beyond, investigating cosmic chemistry, hunting planets, mapping galactic structure, probing dark energy and analyzing the expansion of the wider Universe. Enter the Sloan Digital Sky Survey, a massive scientific collaboration that enables one thousand astronomers from 51 institutions around the world to do just that.

At Tuesday’s AAS briefing in Seattle, researchers announced the public release of data collected by the project’s latest incarnation, SDSS-III. This data release, termed “DR12,” represents the survey’s largest and most detailed collection of measurements yet: 2,000 nights’ worth of brand-new information about nearly 500 million stars and galaxies.

One component of SDSS is exploring dark energy by “listening” for acoustic oscillation signals from the the acceleration of the early Universe, and the team also shared a new animated “fly-through” of the Universe that was created using SDSS data.


The SDSS-III collaboration is based at the powerful 2.5-meter Sloan Foundation Telescope at the Apache Point Observatory in New Mexico. The project itself consists of four component surveys: BOSS, APOGEE, MARVELS, and SEGUE. Each of these surveys applies different trappings to the parent telescope in order to accomplish its own, unique goal.

BOSS (the Baryon Oscillation Spectroscopic Survey) visualizes the way that sound waves produced by interacting matter in the early Universe are reflected in the large-scale structure of our cosmos. These ancient imprints, which date back to the first 500,000 years after the Big Bang, are especially evident in high-redshift objects like luminous-red galaxies and quasars. Three-dimensional models created from BOSS observations will allow astronomers to track the expansion of the Universe over a span of 9 billion years, a feat that, later this year, will pave the way for rigorous assessment of current theories regarding dark energy.

At the press briefing, Daniel Eistenstein from the Harvard-Smithsonian Center for Astrophysics explained how BOSS requires huge volumes of data and that so far 1.4 million galaxies have been mapped. He indicated the data analyzed so far strongly confirm dark energy’s existence.

This tweet from the SDSS twitter account uses a bit of humor to explain how BOSS works:

It turns out that in space, everyone can hear you scream, if you do it in the early Universe and set up acoustic oscillations #aas225

— SDSS — J. Johnson (@sdssurveys) January 6, 2015
APOGEE (the Apache Point Observatory Galactic Evolution Experiment) employs a sophisticated, near-infrared spectrograph to pierce through thick dust and gather light from 100,000 distant red giants. By analyzing the spectral lines that appear in this light, scientists can identify the signatures of 15 different chemical elements that make up the faraway stars – observations that will help researchers piece together the stellar history of our galaxy.

MARVELS (the Multi-Object APO Radial Velocity Exoplanet Large-Area Survey) identifies minuscule wobbles in the orbits of stars, movements that betray the gravitational influence of orbiting planets. The technology itself is unprecedented. “MARVELS is the first large-scale survey to measure these tiny motions for dozens of stars simultaneously,” explained the project’s principal investigator Jian Ge, “which means we can probe and characterize the full population of giant planets in ways that weren’t possible before.”

At the press briefing, Ge said that MARVELS observed 5,500 stars repeatedly, looking for giant exoplanets around these stars. So far, the data has revealed 51 giant planet candidates as well as 38 brown dwarf candidates. Ge added that more will be found with better data processing.



A still photo from an animated flythrough of the universe using SDSS data. This image shows a small part of the large-scale structure of the universe as seen by the SDSS -- just a few of many millions of galaxies. The galaxies are shown in their proper positions from SDSS data. Image credit: Dana Berry / SkyWorks Digital, Inc.


A still photo from an animated flythrough of the universe using SDSS data. This image shows a small part of the large-scale structure of the universe as seen by the SDSS — just a few of many millions of galaxies. The galaxies are shown in their proper positions from SDSS data. Image credit: Dana Berry / SkyWorks Digital, Inc.
SEGUE (the Sloan Extension for Galactic Understanding and Exploration) rounds out the quartet by analyzing visible light from 250,000 stars in the outer reaches of our galaxy. Coincidentally, this survey’s observations “segue” nicely into work being done by other projects within SDSS-III. Constance Rockosi, leader of the SDSS-III domain of SEGUE, recaps the importance of her project’s observations of our outer galaxy: “In combination with the much more detailed view of the inner galaxy from APOGEE, we’re getting a truly holistic picture of the Milky Way.”

One of the most exceptional attributes of SDSS-III is its universality; that is, every byte of juicy information contained in DR12 will be made freely available to professionals, amateurs, and lay public alike. This philosophy enables interested parties from all walks of life to contribute to the advancement of astronomy in whatever capacity they are able.

As momentous as the release of DR12 is for today’s astronomers, however, there is still much more work to be done. “Crossing the DR12 finish line is a huge accomplishment by hundreds of people,” said Daniel Eisenstein, director of the SDSS-III collaboration, “But it’s a big universe out there, so there is plenty more to observe.”

DR12 includes observations made by SDSS-III between July 2008 and June 2014. The project’s successor, SDSS-IV, began its run in July 2014 and will continue observing for six more years.

Here is the video animation of the fly-through of the Universe:





About 

Vanessa earned her bachelor's degree in Astronomy and Physics in 2009 from Wheaton College in Massachusetts. Her credits in astronomy include observing and analyzing eclipsing binary star systems and taking a walk on the theory side as a NSF REU intern, investigating the expansion of the Universe by analyzing its traces in observations of type 1a supernovae. In her spare time she enjoys writing about astrophysics, cosmology, biology, and medicine, making delicious vegetarian meals, taking adventures with her husband and/or Nikon D50, and saving the world.
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Japan’s Akatsuki Spacecraft to Make Second Attempt to Enter Orbit of Venus in December 2015

Japan’s Akatsuki Spacecraft to Make Second Attempt to Enter Orbit of Venus in December 2015:

Artist’s impression of the Venus Climate Orbiter (aka. “Akatsuki”) by Akihiro Ikeshita. Image Credit: JAXA


Artist’s impression of the Venus Climate Orbiter (aka. “Akatsuki”) by Akihiro Ikeshita.
Image Credit: JAXA
Back in 2010, the Japanese Aerospace Exploration Agency (JAXA) launched the The Venus Climate Orbiter “Akatsuki” with the intention of learning more about the planet’s weather and surface conditions. Unfortunately, due to engine trouble, the probe failed to make it into the planet’s orbit.

Since that time, it has remained in a heliocentric orbit, some 134 million kilometers from Venus, conducting scientific studies on the solar wind. However, JAXA is going to make one more attempt to slip the probe into Venus’ orbit before its fuel runs out.

Since 2010, JAXA has been working to keep Akatsuki functioning so that they could give the spacecraft another try at entering Venus’ orbit.

After a thorough examination of all the possibilities for the failure, JAXA determined that the probe’s main engine burned out as it attempted to decelerate on approach to the planet. They claim this was likely due to a malfunctioning valve in the spacecraft’s fuel pressure system caused by salt deposits jamming the valve between the helium pressurization tank and the fuel tank. This resulted in high temperatures that damaged the engine’s combustion chamber throat and nozzle.



A radar view of Venus taken by the Magellan spacecraft, with some gaps filled in by the Pioneer Venus orbiter. Credit: NASA/JPL


A radar view of Venus taken by the Magellan spacecraft, with some gaps filled in by the Pioneer Venus orbiter. Credit: NASA/JPL
JAXA adjusted the spacecraft’s orbit so that it would establish a heliocentric orbit, with the hopes that it would be able to swing by Venus again in the future. Initially, the plan was to make another orbit insertion attempt by the end 2016 when the spacecraft’s orbit would bring it back to Venus. But because the spacecraft’s speed has slowed more than expected, JAXA determined if they slowly decelerated Akatsuki even more, Venus would “catch up with it” even sooner. A quicker return to Venus would also be advantageous in terms of the lifespan of the spacecraft and its equipment.

But this second chance will likely be the final chance, depending on how much damage there is to the engines and other systems. The reasons for making this final attempt are quite obvious. In addition to providing vital information on Venus’ meteorological phenomena and surface conditions, the successful orbital insertion of Akatsuki would also be the first time that Japan deployed a satellite around a planet other than Earth.

If all goes well, Akatsuki will enter orbit around Venus at a distance of roughly 300,000 to 400,000 km from the surface, using the probe’s 12 smaller engines since the main engine remains non-functional. The original mission called for the probe to establish an elliptical orbit that would place it 300 to 80,000 km away from Venus’ surface.

This wide variation in distance was intended to provide the chance to study the planet’s meteorological phenomena and its surface in detail, while still being able to observe atmospheric particles escaping into space.



Artist's impression of Venus Express entering orbit in 2006. Credit: ESA - AOES Medialab


Artist’s impression of Venus Express entering orbit in 2006. Image Credit: ESA – AOES Medialab
At a distance of 400,000 km, the image quality and opportunities to capture them are expected to be diminished. However, JAXA is still confident that it will be able to accomplish most of the mission’s scientific goals.

In its original form, these goals included obtaining meteorological information on Venus using four cameras that capture images in the ultraviolet and infrared wavelengths. These would be responsible for globally mapping clouds and peering beneath the veil of the planet’s thick atmosphere.

Lightning would be detected with a high-speed imager, and radio-science monitors would observe the vertical structure of the atmosphere. In so doing, JAXA hopes to confirm the existence of surface volcanoes and lighting, both of which were first detected by the ESA’s Venus Express spacecraft. One of the original aims of Akatsuki was to compliment the Venus Express mission. But Venus Express has now completed its mission, running out of gas and plunging into the planet’s atmosphere.

But most of all, it is hoped that Akatsuki can provide observational data on the greatest mystery of Venus, which has to do with its surface storms.



Artists impression of lightning storms on Venus. Credit: ESA


Artists impression of lightning storms on Venus. Credit: ESA
Previous observations of the planet have shown that winds that can reach up to 100 m/s (360 km/h or ~225 mph) circle the planet every four to five Earth days. This means that Venus experiences winds that are up to 60 times faster than the speed at which the planet turns, a phenomena known as “Super-rotation”.

Here on Earth, the fastest winds are only capable of reaching between 10 and 20 percent of the planet’s rotation. As such, our current meteorological understanding does not account for these super-high speed winds, and it is hoped that more information on the atmosphere will provide some clues as to how this can happen.

Between the extremely thick clouds, sulfuric rain storms, lightning, and high-speed winds, Venus’ atmosphere is certainly very interesting! Add to the fact that the volcanic, pockmarked surface cannot be surveyed without the help of sophisticated radar or IR imaging, and you begin to understand why JAXA is eager to get their probe into orbit while they still can.

And be sure to check out this video, courtesy of JAXA, detailing the Venus Climate Orbiter mission:



Further Reading: JAXA



About 

Author, freelance writer, educator, Taekwon-Do instructor, and loving hubby, son and Island boy!
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Gallery: Some Of Kepler’s Strange New Worlds Outside The Solar System

Gallery: Some Of Kepler’s Strange New Worlds Outside The Solar System:



Artist's conception of the Kepler 16 system, where the planet Kepler 16-b orbits two stars, much like Tatooine from Star Wars. Credit: NASA/JPL-Caltech/R. Hurt


Artist’s conception of the Kepler 16 system, where the planet Kepler 16-b orbits two stars, much like Tatooine from Star Wars. Credit: NASA/JPL-Caltech/R. Hurt
With the latest Kepler space telescope exoplanet finding announced yesterday, the mighty planet hunter has now found 1,000 confirmed worlds — with about 3,000 more planetary candidates just waiting for confirmation.

The NASA observatory has found exoplanets of many sizes — smaller than Mercury, the size of our Moon, the size of Jupiter or larger, and in a couple of cases, Earth-sized worlds in the habitable regions of their stars. Below is a gallery of some of the observatory’s notable finds.



An artist's conception of a planet in a star cluster. Credit: Michael Bachofner


An artist’s conception of a planet in a star cluster. Credit: Michael Bachofner


An artist's conception of one of the newly released exo-worlds, a planet orbiting an ancient planetary nebula. Credit: David A. Aguilar/CfA.


An artist’s conception of one of the newly released exo-worlds, a planet orbiting an ancient planetary nebula. Credit: David A. Aguilar/CfA.


Meet Kepler-22b, an exoplanet with an Earth-like radius in the habitable zone of its host star. Unfortunately its mass remains unknown. Image Credit: NASA


Meet Kepler-22b, an exoplanet with an Earth-like radius in the habitable zone of its host star. Unfortunately its mass remains unknown. Image Credit: NASA


NASA's Kepler mission has discovered a new planetary system that is home to the smallest planet yet found around a star like our sun, approximately 210 light-years away in the constellation Lyra. Credit: NASA/Ames/JPL-Caltech


NASA’s Kepler mission has discovered a new planetary system that is home to the smallest planet yet found around a star like our sun, approximately 210 light-years away in the constellation Lyra. Credit: NASA/Ames/JPL-Caltech


Artist's Concept of Kepler-20e, one of two Earth-sized planets found by the Kepler spacecraft. Credit: NASA/Ames/JPL-Caltech


Artist’s Concept of Kepler-20e, one of two Earth-sized planets found by the Kepler spacecraft. Credit: NASA/Ames/JPL-Caltech


Kepler-37b, a moon-sized exoplanet. Credit: NASA/Ames/JPL-Caltech


Kepler-37b, a moon-sized exoplanet. Credit: NASA/Ames/JPL-Caltech


Artist's conception of the Kepler-35 system where a Saturn-sized planet orbits its two stars. Credit: © Mark A. Garlick / space-art.co.uk


Artist’s conception of the Kepler-35 system where a Saturn-sized planet orbits its two stars. Credit: © Mark A. Garlick / space-art.co.uk


The "invisible" world Kepler-19c, seen in the foreground of this artist's conception, was discovered solely through its gravitational influence on the companion world Kepler-19b - the dot crossing the star's face. Kepler-19b is slightly more than twice the diameter of Earth, and is probably a "mini-Neptune." Nothing is known about Kepler-19c, other than that it exists. Credit: David A. Aguilar (CfA)


The “invisible” world Kepler-19c, seen in the foreground of this artist’s conception, was discovered solely through its gravitational influence on the companion world Kepler-19b – the dot crossing the star’s face. Kepler-19b is slightly more than twice the diameter of Earth, and is probably a “mini-Neptune.” Nothing is known about Kepler-19c, other than that it exists. Credit: David A. Aguilar (CfA)


Illustration of Kepler-186f, a recently-discovered, possibly Earthlike exoplanet that could be a host to life. (NASA Ames, SETI Institute, JPL-Caltech, T. Pyle)


Illustration of Kepler-186f, a recently-discovered, possibly Earthlike exoplanet that could be a host to life. (NASA Ames, SETI Institute, JPL-Caltech, T. Pyle)


About 

Elizabeth Howell is the senior writer at Universe Today. She also works for Space.com, Space Exploration Network, the NASA Lunar Science Institute, NASA Astrobiology Magazine and LiveScience, among others. Career highlights include watching three shuttle launches, and going on a two-week simulated Mars expedition in rural Utah. You can follow her on Twitter @howellspace or contact her at her website.
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