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Semeis 22: Sharpless 2-188 Planetary Nebula in Cassiopeia

Sharpless2-188 is an old planetary nebula (PN) in the Constellation of Cassiopeia at RA 01h 30m 40s and DEC +58d 22m. It is also known as Semeis 22.

It is categorized as Type Cf PN , which is an extreme example of a crescent-shaped structure where the morphology has been significantly modified by interaction with the interstellar medium (ISM). It is approximately 9’ in diameter with north is toward the right.

The brighter part of the crescent has filamentary structure and is a mixture of strong H-a and OIII emissions. It is about 2800 light years distant, but these distance estimates have very large uncertainties. The central star is moving through the ISM at 125 km/s.

Exoplanet Catalog Reveals 7 Possibly Habitable Worlds

A new catalog aims to list all the known planets in the galaxy that could potentially be habitable to life. The count is at seven so far, with many more to come, researchers said.

Image: More exoplanets than expected in the first year of the Habitable Exoplanets Catalog. Image released Dec. 6, 2012. Credit: PHL @ UPR Arecibo, ESA/Hubble, NASA

The online listing, called the Habitable Exoplanets Catalog, celebrated its first anniversary today (Dec. 5). When it was first released last year, it had two potential habitable planets to its name. According to lead researcher Abel Mendez, the team expected to add maybe one or two more in the catalog’s first year. The addition of five suspected new planets was wholly beyond anyone’s expectations.

“The main purpose is for research, but then I realized that also for the public, it was very important,” said Mendez, director of the University of Puerto Rico at Arecibo’s Planetary Habitability Laboratory.

Bright Clouds on Uranus

The false colors in this image indicate altitude.

Credit: Erich Karkoschka (University of Arizona) and NASA

The green and blue regions show where the atmosphere is clear, allowing sunlight to penetrate deep into Uranus. In the yellow and gray regions, a haze or cloud layer is reflecting sunlight away. Orange and red colors indicate very high clouds, like cirrus clouds on Earth.

Dwarf Planets of Our Solar System

— In 2006 the organization responsible for classifying celestial bodies, the International Astronomical Union, decided that a new class of objects was needed. The solar system’s erratic ninth planet, Pluto, was assigned to the new “dwarf planet” category along with four other bodies, all tinier than Earth’s moon. Some astronomers expect there may be as many as 50 dwarf planets in the solar system.

— Eris, the largest dwarf planet, is only slightly bigger than Pluto, at 1,445 miles in diameter (2,326 km). Discovered in 2003, Eris orbits at an average distance of 68 AU (that is, 68 times the Earth’s distance from the sun) and takes 561.4 Earth years to circle the sun. Eris has the orbit that is most highly inclined of all the dwarf planets, tilted nearly 47 degrees from the plane of the planets’ orbits. A day on Eris takes 25.9 hours. Eris has one moon, Dysnomia.

— Pluto, discovered in 1930, orbits the sun at an average of 39.5 times the Earth’s distance. Its diameter is 1,430 miles (2,302 km). Pluto takes 247.9 Earth years to orbit the sun, and its day is 6.39 times as long as Earth’s. Pluto has five known moons: Charon, Nix, Hydra and two that were recently discovered and have not yet been named.

— Haumea was discovered in 2003. This dwarf planet has an extremely elongated shape, with its longest dimension being about 1,218 miles long (1,960 km). Haumea rotates very rapidly and has the shortest day of all the dwarf planets, only 3.9 hours. Orbiting 43.1 times farther from the sun than Earth does, Haumea takes nearly 282 Earth years to complete one orbit. Haumea has two moons, Hi’iaka and Namaka.

— Makemake, discovered in 2005, has no known moons. Makemake orbits at 45.3 times Earth’s distance and takes more than 305 years to complete a circuit of the sun. Its day is 22.5 hours. Makemake’s average diameter is 882 miles (1,420 km).

— Ceres, first spotted by astronomers in 1801, was first called a planet and later an asteroid. In 2006 it was reclassified as a dwarf planet. Ceres is the closest dwarf planet to Earth, orbiting at only 2.8 times Earth’s distance from the sun. Its year takes 4.6 Earth years and its day is 9.1 hours. Ceres has no known moons.

Meet the Dwarf Planets of the Solar System (Countdown)

Images: Dwarf Planet Eris, Pluto’s Cosmic Twin

Planets.. Planets Everywhere

This artists’s cartoon view gives an impression of how common planets are around the stars in the Milky Way.

The planets, their orbits and their host stars are all vastly magnified compared to their real separations. A six-year search that surveyed millions of stars using the microlensing technique concluded that planets around stars are the rule rather than the exception. The average number of planets per star is greater than one.

NASA’s Prolific Planet-Hunting Mission Goes Into Overtime

NASA’s planet-hunting Kepler Space Telescope has begun its extended mission, which should keep the prolific instrument searching for alien worlds for another four years, agency officials announced today (Nov. 14).

Kepler officially embarked upon the extended mission after completing its 3 1/2-year prime mission, which aimed to determine how common Earth-like planets are throughout the galaxy. The extended phase, which NASA announced this past April, funds the instrument through at least fiscal year 2016.

Kepler is staring at more than 150,000 stars continuously. It detects exoplanets by noticing the tiny brightness dips caused when they transit — or cross the face of — these stars from the telescope’s perspective.

Artist’s Concept of Kepler-20e

NASA’s Kepler mission has discovered the first Earth-size planets orbiting a sun-like star outside our solar system. The planets, called Kepler-20e and Kepler-20f, are too close to their star to be in the so-called habitable zone where liquid water could exist on a planet’s surface, but they are the smallest exoplanets ever confirmed around a star like our sun.

Kepler-20e is the first planet smaller than the Earth discovered to orbit a star other than the sun. A year on Kepler-20e only lasts 6 days, as it is much closer to its host star than the Earth is to the sun. The temperature at the surface of the planet, around 1400 degrees Fahrenheit, is much too hot to support life, as we know it.

Kepler-20e is likely to be entirely rocky and without an atmosphere. The planet is tidally locked, always showing the same side to its host star, as the moon to the Earth, and could have large temperature differences between its permanent night and day sides.

The Kepler-35 System

An artist’s rendition of the Kepler-35 planetary system, in which a Saturn-size planet orbits a pair of stars. Kepler-35b orbits its smaller and cooler host stars than our sun every 131 days, and the stellar pair orbits each other every 21 days.

Alien Planets With Extra Suns Can Have Strange Orbits

The more stars a system of alien worlds starts with, the more likely those planets will orbit those stars at odd tilts, scientists say.

Image: An artist’s illustration of the alien solar system Kepler-47, a twin star system that is home to two planets. The planets have two suns like the fictional planet Tatooine in the “Star Wars” universe. Credit: NASA/JPL-Caltech/T. Pyle

The discovery, based on a study unveiled today (Nov. 14), suggests that even Earth’s own sun may have had a companion star early in its development.

In recent years, astronomers have detected hundreds of exoplanets — worlds circling distant stars. Many of these are “hot Jupiters” — gas giants like Jupiter or Saturn that are closer to their stars than Mercury is to the sun.

Researchers had thought hot Jupiters arose when giant planets were dragged inward by protoplanetary disks of gas and dust falling toward stars. However, this idea was recently cast into doubt by the surprising discovery that a major fraction of hot Jupiters have orbits that are tilted in respect to their stars’ rotation.

Stars all spin, just as Earth’s does, and their worlds often line up with this spin — they orbit around the equators of their stars and revolve in the same direction. However, sometimes alien planets have misaligned orbits instead, ones that are at slight or even sharp angles around their stars. The orbits of some exoplanets are so far tilted that they are actually backwards — they move in retrogradeorbits in exactly the opposite direction of their stars’ spin.

Scientists had thought if hot Jupiters were dragged toward their stars by protoplanetary disks, they would all end up in relatively normal orbits around the equators of their stars. However, astronomers recently discovered that a whopping 25 to 50 percent of these planets actually may have misaligned orbits.

“The misalignments seemed to point towards a much more volatile, violent evolutionary path for hot Jupiters,” said study author Konstantin Batygin, an astrophysicist at the Harvard-Smithsonian Center for Astrophysics.

‘Orphan’ Alien Planet Found Nearby Without Parent Star

Astronomers have discovered a potential “rogue” alien planet wandering alone just 100 light-years from Earth, suggesting that such starless worlds may be extremely common across the galaxy.

Image: This artist’s impression shows the free-floating planet CFBDSIR2149, at 100 light-years away the closest such “rogue” world to our own solar system. It does not orbit a star and hence does not shine by reflected light; the faint glow it emits can only be detected in infrared light. Credit: ESO/L. Calçada/P. Delorme/Nick Risinger (skysurvey.org)/R. Saito/VVV Consortium

The free-floating object, called CFBDSIR2149, is likely a gas giant planet four to seven times more massive than Jupiter, scientists say in a new study unveiled today (Nov. 14). The planet cruises unbound through space relatively close to Earth (in astronomical terms), perhaps after being booted from its own solar system.

“If this little object is a planet that has been ejected from its native system, it conjures up the striking image of orphaned worlds, drifting in the emptiness of space,” study leader Philippe Delorme, of the Institute of Planetology and Astrophysics of Grenoble in France, said in a statement.

Orphan planet, or something else?

Delorme and his team discovered CFBDSIR2149 using the Canada-France-Hawaii Telescope, then examined its properties with the European Southern Observatory’s Very Large Telescope in Chile.

The newfound object appears to be among a stream of young stars called the AB Doradus moving group, the closest such stream to our own solar system.

Scientists think the AB Doradus stars all formed together between 50 million and 120 million years ago. If CFBDSIR2149 is indeed associated with the group — and researchers cite a nearly 90 percent probability — then the object is similarly young.

And if the discovery team is right about CFBDSIR2149’s age, the body is likely a planet, with an average temperature of 806 degrees Fahrenheit (430 degrees Celsius), researchers said.

There’s still a slight chance that CFBDSIR2149 is a brown dwarf — a strange object that’s larger than a planet but too small to trigger the internal nuclear fusion reactions required to become a full-fledged star. Additional observations should help decide the matter.

“We need new observations to confirm that this object belongs to the AB Doradus moving group,” Delorme told SPACE.com via email. “With a good distance measurement and a more accurate proper motion, we will be able to increase (or decrease) the probability that it is indeed a planet.”

The new study was published today in the journal Astronomy & Astrophysics.

Jupiter’s Spots

In what’s beginning to look like a case of planetary measles, a third red spot has appeared alongside its cousins — the Great Red Spot and Red Spot Jr. — in the turbulent Jovian atmosphere.

This third red spot, which is a fraction of the size of the two other features, lies to the west of the Great Red Spot in the same latitude band of clouds.

The new red spot was previously a white oval-shaped storm. The change to a red color indicates its swirling storm clouds are rising to heights like the clouds of the Great Red Spot. One possible explanation is that the red storm is so powerful it dredges material from deep beneath Jupiter’s cloud tops and lifts it to higher altitudes where solar ultraviolet radiation — via some unknown chemical reaction — produces the familiar brick color.

Detailed analysis of the visible-light images taken by Hubble’s Wide Field Planetary Camera 2 on May 9 and 10, and near-infrared adaptive optics images taken by the W.M. Keck telescope on May 11, is revealing the relative altitudes of the cloud tops of the three red ovals. Because all three oval storms are bright in near-infrared light, they must be towering above the methane in Jupiter’s atmosphere, which absorbs the Sun’s infrared light and so looks dark in infrared images.

Turbulence and storms first observed on Jupiter more than two years ago are still raging, as revealed in the latest pictures. The Hubble and Keck images also reveal the change from a rather bland, quiescent band surrounding the Great Red Spot just over a year ago to one of incredible turbulence on both sides of the spot.

Red Spot Jr. appeared in spring of 2006. The Great Red Spot has persisted for as long as 200 to 350 years, based on early telescopic observations. If the new red spot and the Great Red Spot continue on their courses, they will encounter each other in August, and the small oval will either be absorbed or repelled from the Great Red Spot. Red Spot Jr. which lies between the two other spots, and is at a lower latitude, will pass the Great Red Spot in June.

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Massive Planets Might Escape Stellar Engulfment Largely Undiminished

Image: Artist’s conception of the planets orbiting KIC 05807616. Credit: S. Charpinet

Having your planet swallowed by a star is no fun. But some planets might be able to run the astrophysical gauntlet and make it through more or less intact.

When a star comparable to or somewhat larger than the sun enters advanced age, it swells up into a red giant, expanding far beyond its original radius. In the process, the star’s ballooning atmosphere will consume any nearby planets—such is the fate awaiting the planets of the inner solar system, Earth most likely included.

Mercury, Venus and Earth are all too small to endure engulfment, and will quickly spiral in toward the sun due to drag forces from the surrounding stellar atmosphere. Larger planets or substellar objects called brown dwarfs, however, can actually dispel the star’s bloated exterior and survive. But they may emerge somewhat worse for wear. The density of a star’s expanded atmosphere can strip away the outer layers of an orbiting planet, so what comes out may be very different from what went in.

A new study by Jean-Claude Passy of the American Museum of Natural History in New York City and the University of Victoria in British Columbia and his colleagues in the Astrophysical Journal Letters seeks to uncover what a handful of engulfment survivors may have looked like before their close encounter with a star.

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Super-Earth Planet Likely Made of Diamond

Move over, Hope Diamond. The most famous gems on Earth have new competition in the form of a planet made largely of diamond, astronomers say.

Illustration: the interior of 55 Cancri e — an extremely hot planet with a surface of mostly graphite surrounding a thick layer of diamond, below which is a layer of silicon-based minerals and a molten iron core at the center. Credit: Haven Giguere

The alien planet, a so-called “super-Earth,” is called 55 Cancri e and was discovered in 2004 around a nearby star in our Milky Way galaxy. After estimating the planet’s mass and radius, and studying its host star’s composition, scientists now say the rocky world is composed mainly of carbon (in the form of diamond and graphite), as well as iron, silicon carbide, and potentially silicates.

At least a third of the planet’s mass is likely pure diamond.

“This is our first glimpse of a rocky world with a fundamentally different chemistry from Earth,” lead researcher Nikku Madhusudhan of Yale University said in a statement. “The surface of this planet is likely covered in graphite and diamond rather than water and granite.”

55 Cancri e is the first likely “diamond planet” to be identified around a sun-like star, though such worlds have been theorized before. Planets like this are vastly different from our Earth, which has relatively little carbon.

“By contrast, Earth’s interior is rich in oxygen, but extremely poor in carbon — less than a part in thousand by mass,” said study co-author and Yale geophysicist Kanani Lee.

55 Cancri e is what’s known as a super-Earth, with a radius twice as wide as that of our own planet, and a mass eight times greater. It speeds around its host star, making a full orbit in just 18 hours (Earth takes 365 days). It is so close in to the star that its surface temperature reaches a scorching 3,900 degrees Fahrenheit (2,100 degrees Celsius), making it probably way too hot for life.

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Cosmic Garden Sprinkler

Ever wonder what our sun will look like during its eventual death billions of years from now? Here’s something close

The Universe is filled with mysterious objects. Many of them are as strange as they are beautiful. Among these, planetary nebulae are probably one of the most fascinating objects to behold in the night sky. No other type of object has such a large variety of shapes and structures. The NASA/ESA Hubble Space Telescope provides us this week with a striking image of Hen 3-1475, a planetary nebula in the making.

Planetary nebulae — the name arises because most of these objects resembled a planet when they were first discovered through early telescopes — are expanding, glowing shells of gas coming from Sun-like stars at the ends of their lives. They glow brightly because of the radiation that comes from a hot, compact core, which remains after the outer envelope is ejected, and is powerful enough to make these gossamer shells shine.

Each planetary nebula is complex and unique. Hen 3-1475 is a great example of a planetary nebula in the making, a phase which is known to astronomers as a protoplanetary or preplanetary nebula.

Alien Planets Circling Pulsing Stars May Leave Electric Trails

Alien worlds that orbit the energetic dead stars known as pulsars may leave electric currents behind them – anomalies that could help researchers find more of these strange planets.

Image: This artist’s impression shows the planetary system around pulsar PSR B1257+12, one of two pulsars known to be host to at least one planet. Such planets around pulsars may have powerful electromagnetic wakes around them. Credit: NASA/JPL-Caltech/R. Hurt (SSC)

Astronomers know of only four “pulsar planets” so far, and much remains unknown about such worlds, but scientists propose that they formed in the chaos after the supernova explosions that gave birth to the pulsars.

A pulsar is a kind of neutron star, a stellar corpse left over from a supernova, a giant star explosion that crushes protons with electrons to form neutrons. Neutron star matter is the densest known material: A sugar cube-size piece weighs as much as a mountain, about 100 million tons. The mass of a single neutron star surpasses that of the sun while fitting into a ball smaller in diameter than the city of London.

Pulsars spin extraordinarily rapidly, up to thousands of revolutions per second, and they flash like lighthouse beacons — hence their name, which is short for “pulsating star.” They are also extremely magnetic — a kind of pulsar known as a magnetaris the most powerful magnet in the universe.

Despite the exotic nature of pulsars, they have been seen hosting planetary systems.

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