Astronomy and Stars
Discussions about astronomy and stars. As we look further out what can we find in the universe beyond Earth's atmosphere?
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Astronomers using the Hubble Space Telescope have gone looking for water vapor in the atmospheres of three planets orbiting stars similar to the Sun – and have come up nearly dry. The planets spectroscopically surveyed have only one-tenth to one one-thousandth the amount of water predicted by standard planet-formation theories. The planets are not habitable because they are gaseous and are as big as Jupiter. They lie so much closer to their host star than Jupiter is to our Sun, so their atmospheres are seething between 1,500 and 4,000 degrees Fahrenheit. Nevertheless, this result suggests that some percentage of Earth-size exoplanets may be more deficient in water than pr…
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It seems like our compulsive universe can be downright capricious when it comes to making oddball-looking things in the cosmos. The latest surprise to Hubble astronomers is a 100,000-light-year-long structure that looks like a string of pearls twisted into a corkscrew shape. This Slinky-like structure forms a bridge between two giant elliptical galaxies that are colliding. The "pearls" on the Slinky are superclusters of blazing, blue-white, newly born stars. The whole assembly, which looks like a tug-of-war, must result from the gravitational tidal forces present in the collision. If that's not strange enough, the underlying physics behind the "beads on a string" shape …
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Planetary scientists have successfully used the Hubble Space Telescope to boldly look out to the far frontier of the solar system to find suitable targets for NASA's New Horizons mission to Pluto. After the marathon probe zooms past Pluto in July 2015, it will travel across the Kuiper Belt – a vast rim of primitive ice bodies left over from the birth of our solar system 4.6 billion years ago. If NASA approves, the probe could be redirected to fly to a Kuiper Belt object (KBO) and photograph it up close. As a first step, Hubble found two KBOs drifting against the starry background. They may or may not be the ideal target for New Horizons. Nevertheless, the observation is…
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Active galaxies host supermassive black holes in their cores. The intense gravity of the black hole creates a turbulent cauldron of extreme physics. These galaxies, such as NGC 5548 in this study, are too far away for the plasma fireworks to be directly imaged. Therefore astronomers use X-ray and ultraviolet spectroscopy to infer what is happening near the black hole. The new twist is the detection of a clumpy stream of gas that has swept in front of the black hole, blocking its radiation. This deep look into a black hole's environment yields clues to the behavior of active galaxies. The science team consists of J. Kaastra (SRON Utrecht/Universiteit Utrecht/Leiden Unive…
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They may be little, but they pack a big star-forming punch. Hubble astronomers have found that dwarf galaxies in the young universe were responsible for an "early wave" of star formation not long after the big bang. The galaxies churned out stars at a furiously fast rate, far above the "normal" star formation expected of galaxies. Understanding the link between a galaxy's mass and its star-forming activity helps to assemble a consistent picture of events in the early universe. The international team associated with this study consists of H. Atek (EPFL, Switzerland and Spitzer Science Center, California), J.-P. Kneib (EPFL, Switzerland and CNRS, France), C. Pacifici (Yon…
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The Kuiper Belt is the final frontier of our solar system, and also the vastest. Stretching from 3 to 5 billion miles from the Sun, it contains myriad primitive icy bodies left over from the birth of our solar system 4.6 billion years ago. After passing the dwarf planet Pluto in July 2015, NASA's New Horizons space probe will hurtle deep into the Kuiper Belt at nearly 35,000 miles per hour. The Hubble Space Telescope is being used to search for a suitable Kuiper Belt object that New Horizons could pay a visit to. It would be our first and perhaps last look at such a remote relic from the distant past. The search is very challenging even for Hubble's sharp vision. It has t…
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Astronomers using the Hubble Space Telescope have assembled a comprehensive picture of the evolving universe – among the most colorful deep space images ever captured by the 24-year-old telescope. This study, which includes ultraviolet light, provides the missing link in star formation. View the full article
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Jupiter's monster storm, the Great Red Spot, was once so large that three Earths would fit inside it. But new measurements by NASA's Hubble Space Telescope reveal that the largest storm in our solar system has downsized significantly. The red spot, which has been raging for at least a hundred years, is only the width of one Earth. What is happening? One possibility is that some unknown activity in the planet's atmosphere may be draining energy and weakening the storm, causing it to shrink. The Hubble images were taken in 1995, 2009, and 2014. View the full article
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If you need to check whether the prescription for your eye glasses or contact lenses is still accurate, you visit an ophthalmologist for an eye exam. The doctor will ask you to read an eye chart, which tests your visual acuity. Your score helps the doctor determine whether to change your prescription. Astronomers don't have a giant eye chart to check the prescription for natural cosmic lenses, created by galaxy clusters. The gravity of these cosmic lenses warps space around them, magnifying and brightening the light from distant objects behind them. Without these lenses, background objects would be too dim to be detected by even NASA's Hubble Space Telescope. But how do…
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Nearly 2,000 planets have been confirmed to be orbiting other stars in our galaxy. But the details of planet birth and formation are sparse. The conventional wisdom, dating back to a hypothesis by philosopher Immanuel Kant in the late 1700s, considered the orbit of the planets in our solar system to be the skeleton of disks of dust and gas that swirled around the newborn sun. The dust particles clumped together to build planets from the ground up. More than 200 years later the Hubble Space Telescope's exquisite resolution and sensitivity have allowed astronomers to discover dusty disks around young stars. These disks are believed to be fed by dust blasted off newborn pl…
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Astronomers continue refining the precision of distance measurement techniques to better understand the dimensions of the universe. Calculating the age of the universe, its expansion rate, and the nature of dark energy all depend on the precise distance measurements to stars and galaxies. If the astronomical yardsticks are off, the astronomical interpretation may be flawed. The most reliable method for making astronomical distance measurements is to use straightforward geometry where the 186-million-mile diameter of Earth's orbit is used to construct a baseline of a triangle, much as a land surveyor would use. If a target star is close enough, it will appear to zigzag on …
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If someone told you there was an object in space called "El Gordo" (Spanish for "the fat one") you might imagine some kind of planet-eating monster straight out of a science fiction movie. The nickname refers to a monstrous cluster of galaxies that is being viewed at a time when the universe was just half of its current age of 13.8 billion years. This is an object of superlatives. It contains several hundred galaxies swarming around under a collective gravitational pull. The total mass of the cluster, and refined in new Hubble measurements, is estimated to be as much as 3 million billion stars like our Sun (about 3,000 times more massive than our own Milky Way galaxy) – t…
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NASA and the Space Telescope Science Institute (STScI) have announced the selection of 17 new Hubble Fellows. STScI in Baltimore, Md., administers the Hubble Fellowship Program for NASA. The Hubble Fellowship Program includes all research relevant to present and future missions in NASA's Cosmic Origins theme. These missions currently include the Herschel Space Observatory, the Hubble Space Telescope, the James Webb Space Telescope, the Stratospheric Observatory for Infrared Astronomy, and the Spitzer Space Telescope. The new Hubble Fellows will begin their programs in the fall of 2014. View the full article
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Comet Siding Spring is plunging toward the Sun along a roughly 1-million-year orbit. The comet, discovered in 2013, was within the radius of Jupiter's orbit when the Hubble Space Telescope photographed it on March 11, 2014. Hubble resolves two jets of dust coming from the solid icy nucleus. These persistent jets were first seen in Hubble pictures taken on Oct. 29, 2013. The feature should allow astronomers to measure the direction of the nucleus's pole, and hence, rotation axis. The comet will make its closest approach to our Sun on Oct. 25, 2014, at a distance of 130 million miles, well outside Earth's orbit. On its inbound leg, Comet Siding Spring will pass within 84,00…
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This colorful Hubble Space Telescope mosaic of a small portion of the Monkey Head Nebula unveils a collection of carved knots of gas and dust silhouetted against glowing gas. The cloud is sculpted by ultraviolet light eating into the cool hydrogen gas. As the interstellar dust particles are warmed from the radiation from the stars in the center of the nebula, they heat up and begin to glow at infrared wavelengths, as captured by Hubble. The space photo superficially resembles the "The Great Wave" print by 19th century Japanese artist Katsushika Hokusai. View the full article
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Though fragile comet nuclei have been seen falling apart as they near the Sun, nothing like the slow breakup of an asteroid has ever before been observed in the asteroid belt. A series of Hubble Space Telescope images shows that the fragments are drifting away from each other at a leisurely one mile per hour. This makes it unlikely that the asteroid is disintegrating because of a collision with another asteroid. A plausible explanation is that the asteroid is crumbling due to a subtle effect of sunlight. This causes the rotation rate to slowly increase until centrifugal force pulls the asteroid apart. The asteroid's remnant debris, weighing in at 200,000 tons, will in the…
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Our spiral-shaped Milky Way galaxy lives in a comparatively quiet backwater region of the universe. This is not the case for galaxies crammed together inside huge clusters. As they zip around within a cluster, gas can be pulled from their disks due to a process called ram pressure stripping. Galaxy ESO 137-001 is one example. The star-city looks like it is "leaking" as it plunges through the Norma galaxy cluster. View the full article
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This is a Hubble Space Telescope composite image of a supernova explosion designated SN 2014J in the galaxy M82, at a distance of approximately 11.5 million light-years from Earth. Astronomers using a ground-based telescope discovered the explosion on January 21, 2014. This Hubble photograph was taken on January 31, as the supernova approached its peak brightness. View the full article
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Using the sharp-eyed NASA Hubble Space Telescope, astronomers have for the first time precisely measured the rotation rate of a galaxy based on the clock-like movement of its stars. According to their analysis, the central part of the neighboring galaxy, called the Large Magellanic Cloud (LMC), completes a rotation every 250 million years. Coincidentally, it takes our Sun the same amount of time to complete a rotation around the center of our Milky Way galaxy. The arrows in this photo illustration represent the highest-quality Hubble measurements of the motion of the LMC's stars to show how the galaxy rotates. View the full article
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An international team led by astronomers from the Instituto de Astrofisica de Canarias (IAC) and La Laguna University (ULL) has just released the first analysis of the observations of the Abell 2744 cluster of galaxies, a coordinated program of the Hubble and Spitzer space telescopes. They have discovered one of the most distant galaxies known to date, which clearly shows the potential of the multi-year Frontier Fields project. The project uses a phenomenon called "gravitational lensing" where select foreground galaxy clusters amplify the faint light from far-more-distant background objects. By combining Hubble and Spitzer data, these astrophysicists have determined the p…
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Imagine living on a planet with seasons so unpredictable you would hardly know what to wear: Bermuda shorts or a heavy overcoat! That's the situation on a weird world found by NASA's planet-hunting Kepler space telescope. The planet, designated Kepler-413b, is located 2,300 light-years away in the constellation Cygnus. It circles a close pair of orange and red dwarf stars every 66 days. But what makes this planet very unusual is that it wobbles, or precesses, wildly on its spin axis, much like a child's top. The planet's orbit is tilted with respect to the plane of the binary star's orbit. Over an 11-year period, the planet's orbit too would appear to wobble as it circles…
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A certain class of massive galaxies in the early universe lived fast and died young. By "died" astronomers mean that the galaxies had completed building stars just 3 billion years after the big bang. By contrast, our 12-billion-year-old Milky Way galaxy continues making stars today. When star formation stops, the aging stellar population looks redder in the star-forming galaxies that are more bluish. The nickname for the essentially "burned-out" galaxies is "red and dead." By combining the power of Hubble with infrared space-based telescopes and ground-based telescopes, astronomers have now solved a decade-long mystery as to how compact elliptical-shaped galaxies existe…
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Michael Hauser, former deputy director of the Space Telescope Science Institute (STScI) and an adjunct professor in the Johns Hopkins University's Physics and Astronomy Department, will receive the 2014 George Van Biesbroeck Prize from the American Astronomical Society (AAS). The prize honors a living individual for long-term extraordinary or unselfish service to astronomy, often beyond the requirements of his or her paid position. In its citation, the Van Biesbroeck Prize committee recognized Hauser's long service to the astronomy community. The committee emphasized Hauser's "strategic vision" in establishing and leading the infrared group at NASA's Goddard Space Fligh…
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This huge Hubble Space Telescope mosaic, spanning a width of 600 light-years, shows a star factory of more the 800,000 stars being born. The stars are embedded inside the Tarantula Nebula, a vibrant region of star birth that resides 170,000 light-years away in the Large Magellanic Cloud, a small, satellite galaxy of our Milky Way. Hubble's near-infrared sensitivity allows astronomers to see behind clouds of dust in the nebula to unveil where the newborn stars are clustered. View the full article
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The vibrant magentas and blues in this Hubble image of the barred spiral galaxy M83 reveal that the galaxy is ablaze with star formation. The galactic panorama unveils a tapestry of the drama of stellar birth and death. The galaxy, also known as the Southern Pinwheel, lies 15 million light-years away in the constellation Hydra. This image is being used to support a citizen science project titled STAR DATE: M83. The primary goal is to estimate ages for approximately 3,000 star clusters. Amateur scientists will use the presence or absence of the pink hydrogen emission, the sharpness of the individual stars, and the color of the clusters to estimate ages. Participants will…
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