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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The weather forecast for a planet 120 light-years from Earth is clear skies and steamy water vapor. Finding clear skies on a gaseous world the size of Neptune is a good sign that even smaller, Earth-size planets might have similarly good visibility. This would allow earthbound astronomers to measure the underlying atmospheric composition of an exoplanet. Astronomers using the Hubble, Spitzer, and Kepler space telescopes were able to determine that the planet, cataloged HAT-P-11b, has water vapor in its atmosphere. The world is definitely steamy with temperatures over 1,000 degrees Fahrenheit. The planet is so hot because it orbits so close to its star, completing one orbi…
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Astronomers have found an unlikely object in an improbable place: a monster black hole lurking inside one of the tiniest galaxies known. The dwarf galaxy containing the black hole is the densest galaxy ever seen, cramming 140 million stars within a diameter of about 300 light-years (just 1/500th of our Milky Way galaxy's diameter). However, the black hole inside the galaxy is five times the mass of the black hole at the center of our Milky Way. This suggests that the dwarf galaxy may actually be the stripped remnant of a larger galaxy that was torn apart during a close encounter with a more massive galaxy. The finding implies that there are many other compact galaxies in …
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For over two decades astronomers have been patiently monitoring the fading glow of a supernova in a nearby galaxy. They've been looking for a suspected companion star that pulled off almost all of the hydrogen from the doomed star that exploded. At last Hubble's ultraviolet-light sensitivity pulled out the blue glow of the star from the cluttered starlight in the disk of the galaxy. This observation confirms the theory that the supernova originated in a double-star system where one star fueled the mass-loss from the aging primary star. The surviving star's brightness and estimated mass provide insight into the conditions that preceded the 1993 explosion. View the f…
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Children with visual disabilities can experience striking deep-space images in a free, multi-touch iBooks textbook for the iPad entitled "Reach for the Stars: Touch, Look, Listen, Learn." Astronomers at the Space Telescope Science Institute have teamed up with the SAS Corporation, the National Braille Press, and the National Federation of the Blind to create a book to inspire students of all abilities. Students with visual impairments can access the book using the VoiceOver screen reader that is available on every iPad. The book is available as a free download from Apple's iBooks Store. View the full article
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The birth of massive galaxies, according to galaxy formation theories, begins with the buildup of a dense, compact core that is ablaze with the glow of millions of newly formed stars. Evidence of this early construction phase, however, has eluded astronomers until now. Astronomers identified a dense galactic core, dubbed "Sparky," using a combination of data from Hubble and Spitzer, other space telescopes, and the W.M. Keck Observatory in Hawaii. Hubble photographed the emerging galaxy as it looked 11 billion years ago, just 3 billion years after the birth of our universe in the big bang. This illustration reveals the celestial fireworks deep inside the crowded core of …
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Supernovae are the most powerful stellar explosions in the universe. Some of them are produced by the detonation of a white dwarf, the stripped-down core of an ordinary star at the end of its life. But 12 years ago, astronomers began noticing weak stellar blasts, a kind of mini-supernova. When one such explosion occurred in the galaxy NGC 1309, astronomers looking through Hubble archival images found for the first time the star system that produced the supernova blast of a white dwarf. The inset panel from 2013 shows the supernova; archival Hubble data from 2005 and 2006 show the progenitor system for the supernova, thought to be a binary system containing a helium star…
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Astronomers using NASA's Hubble Space Telescope have unexpectedly discovered the most distant cosmic magnifying glass yet, produced by a monster elliptical galaxy. The galaxy, seen here as it looked 9.6 billion years ago, is so massive that its gravity bends, magnifies, and distorts light from objects behind it, a phenomenon called gravitational lensing. In the Hubble image, the galaxy is the red object in the enlarged view at left. The object behind the cosmic lens is a tiny spiral galaxy undergoing a rapid burst of star formation. Its light has taken 10.7 billion years to arrive here. In the Hubble image, the galaxy is seen in the enlarged view at right. Seeing this c…
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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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