This image was obtained with the wide-field view of the Mosaic camera on the Mayall 4-meter telescope at Kitt Peak National Observatory. Abell 74 is an ancient planetary nebula. Because of its age it is a very faint target. Ancient planetary nebulae are often distorted in shape due to interactions with the interstellar medium. Interestingly, Abell 74 is remarkably symmetric despite its age. The image was generated with observations in the Hydrogen alpha (red) and Oxygen [OIII] (blue) filters. In this image, North is left, East is down.
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T.A. RECTOR (UNIVERSITY OF ALASKA ANCHORAGE) AND H. SCHWEIKER (WIYN AND NOAO/AURA/NSF)
Posted by Daniel Stolte-Arizona on March 6, 2014
For the first time, astronomers have used the same imaging technology found in a digital camera to take a picture of a planet far from our solar system with an Earth-based telescope.
While the technology, which replaces an infrared detector, still has a very long way to go, scientists say the accomplishment brings them a small step closer to what will be needed to image Earth-like planets around other stars.
“This is an important next step in the search for exoplanets because imaging in visible light instead of infrared is what we likely have to do if we want to detect planets that might be suitable for harboring life,” says Jared Males, a NASA Sagan Fellow in the department of astronomy and Steward Observatory at the University of Arizona and lead author of a paper to be published in The Astrophysical Journal.
An image of the exoplanet Beta Pictoris b taken with the Magellan Adaptive Optics VisAO camera. This image was made using a CCD camera, which is essentially the same technology as a digital camera. The planet is nearly 100,000 times fainter than its star, and orbits its star at roughly the same distance as Saturn from our Sun. (Image: Jared Males/U. Arizona)
Even though the image was taken at a wavelength that is just shy of being visible to the human eye, the use of a digital camera-type imaging sensor—called a charge-coupled device or CCD—opens up the possibility of imaging planets in visible light, which has not been possible previously with Earth-based telescopes.
“This is exciting to astronomers because it means we now are a small step closer to being able to image planets outside our solar system in visible light,” says co-author Laird Close, professor of astronomy.
All the other Earth-based images taken of exoplanets close to their stars are infrared images, which detect the planets’ heat. This limits the technology to gas giants—massive, hot planets young enough to still shed heat.
In contrast, older, possibly habitable planets that have cooled since their formation don’t show up in infrared images as readily, and to image them, astronomers will have to rely on cameras capable of detecting visible light, Close says.
“Our ultimate goal is to be able to image what we call pale blue dots. After all, the Earth is blue. And that’s where you want to look for other planets: in reflected blue light.”
The photographed planet, called Beta Pictoris b, orbits its star at only nine times the Earth-Sun distance, making its orbit smaller than Saturn’s. In the team’s CCD images, Beta Pictoris b appears about 100,000 times fainter than its host star, making it the faintest object imaged so far at such high contrast and at such relative proximity to its star.
The new images of this planet helped confirm that its atmosphere is at a temperature of roughly 2600 degrees Fahrenheit (1700 Kelvin). The team estimates that Beta Pictoris b weighs in at about 12 times the mass of Jupiter.
“Because the Beta Pictoris system is 63.4 light years from Earth, the scenario is equivalent to imaging a dime next right next to a lighthouse beam from more than four miles away,” Males says. “Our image has the highest contrast ever achieved on an exoplanet that is so close to its star.”
The contrast in brightness between the bright star and the faint planet is similar to the height of a 4-inch molehill next to Mount Everest, Close says.
In addition to the host star’s overwhelming brightness, the astronomers had to overcome the turbulence in Earth’s atmosphere, which causes stars to twinkle and telescope images to blur.
The success reported here is mostly due to an adaptive optics system that eliminates much of the atmosphere’s effect. The Magellan Adaptive Optics technology is very good at removing this turbulence, or blurring, by means of a deformable mirror changing shape 1,000 times each second in real time.
Adaptive optics have been used for more than 20 years at observatories in Arizona, most recently at the Large Binocular Telescope, and the latest version has now been deployed in the high desert of Chile at the Magellan 6.5-meter telescope.
The team also imaged the planet with both of MagAO’s cameras, giving the scientists two completely independent simultaneous images of the same object in infrared as well as bluer light to compare and contrast.
“An important part of the signal processing is proving that the tiny dot of light is really the planet and not a speckle of noise,” says Katie Morzinski, who is also a Sagan Fellow and member of the MagAO team.
“I obtained the second image in the infrared spectrum—at which the hot planet shines brightly—to serve as an unequivocal control that we are indeed looking at the planet. Taking the two images simultaneously helps to prove the planet image on the CCD is real and not just noise.”
“In our case, we were able to record the planet’s own glow because it is still young and hot enough so that its signal stood out against the noise introduced by atmospheric blurring,” Males says.
“But when you go yet another 100,000 times fainter to spot much cooler and truly earthlike planets, we reach a situation in which the residual blurring from the atmosphere is too large and we may have to resort to a specialized space telescope instead.”
Development of the MagAO system was supported by the National Science Foundation. The Magellan telescopes are operated by a partnership of the Carnegie institute, the University of Arizona, Harvard University, Massachusetts Institute of Technology, and the University of Michigan.
The work of NASA Sagan Fellows Jared Males and Katie Morzinski was performed in part under contract with the California Institute of Technology funded by NASA through the Sagan Fellowship Program executed by the NASA Exoplanet Science Institute.
What Would Make You Abandon Earth For Mars Forever?:
Regardless of whether Mars One actually puts a team of astronauts on the Red Planet, over a thousand people are currently competing to be sent into space and never return. The short documentary “Mars One Way,” made by Vita Bretis Films and Video West, will tell you why five of them want to make that trip, and what they’re leaving behind: wives, boyfriends, children, and virtually every other known living thing in the universe.
Mars One has produced its own set of would-be astronaut profiles, called “One Way Astronaut.” But while the trailer to that film focuses on the thrill of exploration, “Mars One Way” is about coming to terms with abandoning Earth forever, whether you’re doing it out of a pioneer spirit or crippling depression. “Once you’re gone, you are technically dead here on Earth,” says one applicant. “And I’m okay with that.”
If any of these people are chosen as finalists and the Mars One mission proceeds, they wouldn’t leave until 2025 at the earliest. ”I hope it’s a success. I hope it’s not basically suicide,” another applicant says. “But if it is, i’ve got ten years to live it up here on Earth.”
An astrophysicist is using something called the Z machine at Sandia National Lab to recreate the conditions on a white dwarf star â only for a few nanoseconds, but still, enough to study.
Elon Musk To Congress: ‘Here’s Why You Should Pick SpaceX’:
The U.S. Air Force is looking for new waysto get its spy and GPS satellites into space for less money through their EELV (Evolved Expendable Launch Vehicle) program. Currently United Launch Alliance, the joint venture of Lockheed Martin and Boeing, launches these satellites. But the rocket establishment is facing some competition in the form of Elon Musk and SpaceX.
In ULA’s favor: It has completed 68 consecutive missions for the Air Force. In SpaceX’s favor: It claims it can do the job for less. And as PopMech previously reported, there’s something else: ULA’s Atlas V and Delta IV rockets use Russian-made rocket engines, a prickly issue now that the West and Russia are at odds over Crimea.
The two sides made their case on Capitol Hill this week. Wednesday morning, the Senate Defense Subcommittee heard testimony from Musk, Michael Gass, president and CEO of ULA, and others. Sparks flew. Here are, in their own words, the best zingers from the Q&A that followed the testimonies.
Subcommittee chairman Dick Durbin brings up possible sanctions against Russia, and mentions the reliance on Russian-made RD-180 engines:
Michael Gass: ”We have two years of safety stock inventory. We are not at any risk for supporting our national leads. We have always kept our ability not to be leveraged in case of supply interruption.”
Durbin: ”Mr. Musk, ULA has a flawless record. Your suggestion is that we’ve paid dearly for it, and could pay a lot less now. Do you believe it is possible to maintain two companies for future launches?”
Elon Musk: ”The premise of perfect success for ULA is not quite correct—they certainly have a good record. What would make sense for long-term security is to phase out the Atlas IV, which depends on the Russian engine, have ULA operate the Delta family and SpaceX operate the Falcon family.”
Durbin on whether the Pentagon should give ULA a special break on launches:
Gass: ”ELC [EELV Launch Capacity, the contract awarded to ULA] is not a subsidy. It’s about providing national security capability with a laser focus on mission success. I also encourage the committee to think about it as a pendulum. We swung to the commercial model, then to the DOD contract model, and now we’re swinging back to the middle.”
Sen. Thad Cochran asks whether, given ULA’s record of successful missions, it makes sense to change things.
Musk: ”I think as a country we’ve generally decided that competition in the free market is a good thing and monopolies are not so good. The reality is, when competition is introduced, reliability is a key factor in competition. Frankly, if our rockets are good enough for NASA, why are they not good enough for the Air Force?”
Sen. Dianne Feinstein asks Musk what challenges he anticipates for SpaceX regarding the certification program currently required by the Air Force.
Musk: ”We’re not aware of any issue that would prevent us from being certified to fly missions, completing that certification this year. We are concerned about any delays in the contracting—hopefully those delays don’t materialize.”
Sen. Richard Shelby: ”Mr. Musk, do you ignore the fact that ULA currently complies with the mandates that you acknowledge add overhead costs? It seems that you are comparing apples and oranges in your price estimates. And why should SpaceX be exempt from the same auditing and oversight rules that DOD requires of the ULA?”
Musk: ”Because the government does not buy launch insurance. In order to improve the probability of success, there is substantial mission-assurance overhead applied. This is why our launch costs are estimated to be 50 percent higher for Air Force flights than commercial flights. So instead of $60 million for a commercial missions, it’s $90 million. But that compares to more like $380 million for ULA.”
Shelby asks Musk what he thinks about ULA’s 68 consecutive launches.
Musk: ”I would also like to point out that there were two highly publicized failure investigations, one into Delta IV Heavy and one into Atlas, that the Air Force conducted. ULA has a very good track record; it is not quite as perfect as 68 launches.”
Gass: ”We measure mission success by our customer’s declaration, so if they declare a mission is a success, we use the same record”.
Shelby: ”Mr. Musk, in October 2012, a secondary payload aboard a Space X Falcon 9 was sent into the wrong orbit because one of the Merlin engines powering the Falcon 9 failed.”
Musk: ”Right. Well, by ULA’s definition of success, that mission was perfect.”
Cancer? Here’s Your Constellation:
Chances are you’ve never seen Cancer the Crab, the faintest of the 13 constellations of the Zodiac. Cancer the Crab may be found between the two brightest stars of Gemini (Castor and Pollux) and Leo’s brightest star (Regulus). Follow the links below to learn more about this constellation.
How to find the constellation Cancer. In the Northern Hemisphere, Cancer is best seen in the evening sky in late winter and early spring. It is lost in the sun’s glare in July and August, and then is found in the morning sky starting in September. If you’re up before dawn during a Northern Hemisphere autumn, try finding Cancer and its Beehive star cluster.
Let’s suppose you have identified the Leo star Regulus, and the Gemini stars Castor and Pollux – and you look between them for Cancer and see, well, nothing much. Remember, Cancer is faint. Our advice is to look for it in a dark country sky.
Cancer is always well placed for viewing in March, and it is also well placed for evening viewing in April and May. It starts to descend into the sunset glare in June.
In early March every year, look for the constellation Cancer to be due south and highest up in the sky around 10 p.m. local time. (From the tropics, Cancer shines high overhead, and from temperate latitudes in the Southern Hemisphere, Cancer appears due north.) Because the stars return to the same place in the sky about four minutes earlier each day, or one-half hour earlier weekly, look for Cancer to be highest in the sky in mid-March at 9 p.m. local time (10 p.m. local daylight saving time). By late March or early April, Cancer reaches its high point for the night at 8 p.m. local time (9 p.m. local daylight saving time).
On a moonless night, Cancer is surprisingly easy to see in a dark country sky. You can locate the Crab’s place on the Zodiac by referring to certain zodiacal stars. The two brightest stars in theconstellation Gemini, Castor and Pollux, shine on one side of Cancer, while Regulus, the brightest star in the constellation Leo, lies on the other side.
Cancer’s famous Beehive star cluster. Cancer makes up for its lackluster stars by having within its boundaries one of the sky’s brighter star clusters, the Beehive cluster, also known as M44. Another name for the Beehive is Praesepe (Latin for “manger”).
In a dark sky, the Beehive looks like a tiny faint cloud to the unaided eye. As seen through ordinary binoculars, this nebulous patch of haze instantly turns into a sparkling city of stars. It is an open cluster, one of the nearest to our solar system. The Beehive is thought to contain a larger star population than most other nearby clusters.
The Beehive’s stars appear to be similar in age and proper motion to stars of the V-shaped Hyades open star cluster. It’s possible the two clusters were born from two parts of a single vast cloud of gas and dust in space.
Significance of constellation Cancer. Cancer’s stature as a constellation of the Zodiac has remained steadfast over the millennia. Over two thousand years ago, the sun shone in front of the constellation Cancer during the Northern Hemisphere’s summer solstice. That’s not the case today, however.
Today, the sun resides in front of the constellation Taurus when the summer solstice sun reaches its northernmost point for the year on or near June 20.
Nonetheless, Cancer still seems to symbolize the height and glory of the summer sun. To this day, we say the sun shines over the Tropic of Cancer – not the “tropic of Taurus” – on the June solstice. That’s in spite of the fact that the sun in our time passes in front of the constellation Cancer from about July 20 until August 10.
Nowadays, the sun doesn’t enter the constellation Cancer until about a month after the Northern Hemisphere’s summer solstice.
Cancer in history, myth and science. According to Richard Hinckley Allen, in his book Star Names: Their Lore and Meaning, astrologers call Cancer the House of the Moon from the early belief that the moon was located here at creation.
In astrology, the moon is said to rule Cancer. Astrology differs from astronomy in that astrologers assume positions of heavenly bodies have certain influences over human affairs. Astronomers generally regard the supposed connections as unfounded and view astrology as a pseudo-science.
Interestingly enough, however, modern-day astronomers believe the sun might have originated from Cancer’s fainter star cluster, Messier 67, though this study seems to throw cold water on the idea. Still, it looks as if Cancer may be the home of a creation story in both astrology and astronomy.
In ancient Chaldean and Platonic philosophy, Cancer was called the Gate of Men. It was through this portal that souls descend from the heavens above and into the bodies of the newly born.
Around 2700 years ago, the sun passed in front of the Beehive cluster on the Northern Hemisphere’s summer solstice. Back then, this cluster stood at the apex of the Zodiac, so perhaps it was this heavenly nebulosity that marked the Gate of Men. At present, the sun has its annual conjunction with the Beehive cluster in late July or early August.
In olden times, before the advent of light pollution, the ancients referred to the Beehive as the Praesepe (“little cloud”). The Roman author Pliny reports that when the Praesepe is invisible in an otherwise clear sky, it’s a sure sign of impending storm. Yes, the Beehive cluster once served as a celestial weather station.
Although Cancer may be the faintest constellation of the Zodiac, its legacy remains intact. On a dark, moonless night, look for Cancer’s faint grouping of stars to spring out in between the more conspicuous constellations Gemini and Leo.
Bottom line: Looking for the constellation Cancer? How to find it here. Plus Cancer’s place in sky history, lore and science.
Multiple images of a distant quasar are visible in this combined view from NASA’s Chandra X-ray Observatory and the Hubble Space Telescope. The Chandra data, along with data from ESA’s XMM-Newton, were used to directly measure the spin of the supermassive black hole powering this quasar. This is the most distant black hole where such a measurement has been made, as reported in our press release.
Gravitational lensing by an intervening elliptical galaxy has created four different images of the quasar, shown by the Chandra data in pink. Such lensing, first predicted by Einstein, offers a rare opportunity to study regions close to the black hole in distant quasars, by acting as a natural telescope and magnifying the light from these sources. The Hubble data in red, green and blue shows the elliptical galaxy in the middle of the image, along with other galaxies in the field.
The quasar is known as RX J1131-1231 (RX J1131 for short), located about 6 billion light years from Earth. Using the gravitational lens, a high quality X-ray spectrum - that is, the amount of X-rays seen at different energies - of RX J1131 was obtained.
The X-rays are produced when a swirling accretion disk of gas and dust that surrounds the black hole creates a multimillion-degree cloud, or corona near the black hole. X-rays from this corona reflect off the inner edge of the accretion disk. The reflected X-ray spectrum is altered by the strong gravitational forces near the black hole. The larger the change in the spectrum, the closer the inner edge of the disk must be to the black hole.
The authors of the new study found that the X-rays are coming from a region in the disk located only about three times the radius of the event horizon, the point of no return for infalling matter. This implies that the black hole must be spinning extremely rapidly to allow a disk to survive at such a small radius. This result is important because black holes are defined by just two simple characteristics: mass and spin. While astronomers have long been able to measure black hole masses very effectively, determining their spins have been much more difficult.
These spin measurements can give researchers important clues about how black holes grow over time. If black holes grow mainly from collisions and mergers between galaxies they should accumulate material in a stable disk, and the steady supply of new material from the disk should lead to rapidly spinning black holes. In contrast if black holes grow through many small accretion episodes, they will accumulate material from random directions. Like a merry go round that is pushed both backwards and forwards, this would make the black hole spin more slowly.
he discovery that the black hole in RX J1131 is spinning at over half the speed of light suggests that this black hole has grown via mergers, rather than pulling material in from different directions. These results were published online in the journal Nature. The lead author is Rubens Reis of the University of Michigan. His co-authors are Mark Reynolds and Jon M. Miller, also of Michigan, as well as Dominic Walton of the California Institute of Technology.
Caption: Chandra Telescope Team
X-RAY: NASA/CXC/UNIV OF MICHIGAN/R.C.REIS ET AL; OPTICAL: NASA/STSCI
Plasma Plume Keeps Earth Safe From Solar Storms:
Earth has a magnetic field, which begins at the core and stretches far out into space. Typically, this magnetic field is a useful shield for solar activity. However, if the Earth’s magnetic field bumps up against the sun’s magnetic field, all types of madness can ensue, including geomagnetic storms, or space weather that can affect the International Space Station.
This meeting of the magnetic fields is known as magnetic reconnection. During this process, the sun’s electrical currents can enter Earth’s atmosphere, and in the process, some of our own magnetic field gets stripped away. A new study from MIT and NASA, published in the journalScience this week, explores how a plume of plasma adds extra reinforcements to keep us earthlings safe during solar activity.
The plume is not terribly unlike a river, with particles that flow through a stream. ”This higher-density, cold plasma changes about every plasma physics process it comes in contact with,” MIT Haystack Observatory associate director John Foster said in a statement. “It slows down reconnection, and it can contribute to the generation of waves that, in turn, accelerate particles in other parts of the magnetosphere. So it’s a recirculation process, and really fascinating.”
Since space weather events create radio wave distortion, scientists at the Haystack Observatory have been analyzing radio signals to determine plasma particle concentration, using the data to map the plasma plumes from Earth. While they have been performing the research for 10 years, the researchers note that this is still just an estimate. So the team matched the Earth-based research with space-based data, monitoring a solar storm last January. Three spacecraft crossed one point in the magnetic field where a plasma plume was estimated to be. Data from those craft confirmed that dense plasma plume, which extended to the place where Earth’s field met the solar storm.