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 scorching hot exoplanet WASP-121b represents a new twist on the phrase "heavy metal." There are no loud electric guitar riffs, characteristic of heavy metal music, streaming into space. What is escaping the planet is iron and magnesium gas, dubbed heavy metals, because they are heavier than lightweight hydrogen and helium. The observations by the Hubble Space Telescope represent the first time heavy metal gas has been detected floating away from an exoplanet. A scorching planet, WASP-121b orbits precariously close to a star that is even hotter than our Sun. The intense radiation heats the planet's upper atmosphere to a blazing 4,600 degrees Fahrenheit. Apparently,…
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In 1924, American astronomer Edwin Hubble announced that he discovered galaxies outside of our Milky Way by using the powerful new Hooker telescope perched above Los Angeles. By measuring the distances to these galaxies, he realized the farther away a galaxy is, the faster it appears to be receding from us. This was incontrovertible evidence the universe is uniformly expanding in all directions. For nearly a decade Albert Einstein refused to accept the observational evidence. His theory of general relativity described a static universe. But this could only be accomplished by invoking a "cosmological constant," which he described as repulsive property of space that would c…
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Astronomers are always tickled when they find something they didn't expect to be there. Peering deep into the heart of the majestic spiral galaxy NGC 3147, researchers uncovered a swirling gas disk precariously close to a black hole weighing about 250 million times the mass of our Sun. The surprise is that they thought the black hole was so malnourished, it shouldn’t have such a structure around it. It's basically a "Mini-Me" version of more powerful disks seen in very active galaxies. What's especially intriguing is that the disk is so deeply embedded in the black hole's intense gravitational field, its light is being stretched and intensified by the black hole's power…
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NASA has awarded a contract to the Space Telescope Science Institute (STScI) in Baltimore, Maryland, for the Science Operations Center (SOC) of the Wide Field Infrared Survey Telescope (WFIRST) mission. WFIRST is a NASA observatory designed to settle essential questions in a wide-range of science areas, including dark energy and dark matter, and planets outside our solar system. View the full article
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Our solar system contains two major classes of planets. Earth is a rocky terrestrial planet, as are Mercury, Venus, and Mars. At about the distance of the asteroid belt, there is a "frost line" where space is so cold more volatile material, like water, can remain frozen. Out here live the gas giants–Jupiter, Saturn, Uranus, and Neptune–which have bulked up on hydrogen and helium and other volatiles. Astronomers are curious about a new class of planet not found in the Solar System. Weighing in at 12.6 Earth masses the planet is more massive than Earth, but less massive than Neptune (hence, intermediate between the rocky and gaseous planets in the Solar System). What's mo…
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In the mid-1800s, mariners sailing the southern seas navigated at night by a brilliant star in the constellation Carina. The star, named Eta Carinae, was the second brightest star in the sky for more than a decade. Those mariners could hardly have imagined that by the mid-1860s the brilliant orb would no longer be visible. Eta Carinae was enveloped by a cloud of dust ejected during a violent outburst. Stars don't normally play vanishing acts unless they are undergoing rapid and violent activity. Observations by the Hubble Space Telescope and other observatories have helped astronomers piece together the story of this unique star's petulant behavior. During part of its a…
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Finding common table salt — sodium chloride — on the surface of a moon is more than just a scientific curiosity when that moon is Europa, a potential abode of life. If the salt came from the briny subsurface ocean of Europa, a satellite of Jupiter, that ocean may chemically resemble Earth's oceans more than previously thought. Because Europa's solid, icy crust is geologically young it has been suspected that whatever salts exist on the surface may come from the ocean below, which might host microorganisms. Using visible-light spectral analysis, planetary scientists at Caltech and NASA's Jet Propulsion Laboratory discovered that the yellow color visible on portions of…
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In order to grow to Jupiter size or larger, a gas giant planet must slurp large quantities of hydrogen and other gases from the disk in which it forms. Astronomers have looked for evidence of this process, but direct observations are challenging because planets become lost in the glare of their star. A team has succeeded in making ground-based observations of two planets accreting matter from a disk. It represents only the second multi-planet system to be directly imaged. View the full article
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One doesn't need a Ph.D. in astrophysics to recognize there is something odd-looking about this otherwise beautiful galaxy, NCG 4485. Like the Batman character Two-Face, one side looks normal, but the other side looks contorted with a firestorm of star formation going on. Why the colorful asymmetry in an island star city many thousands of light-years across? The clue is off the edge of the photo. It's another galaxy, NGC 4490, that swept by NGC 4485 millions of years ago. The gravitational taffy pull between the two galaxies compressed interstellar gas to trigger a flurry of new star birth as seen in the abundance of young blue stars and pinkish nebulas. So, out of a near…
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How far is far? And, how do you know when you get there? In 1995, astronomers decided to use the Hubble Space Telescope to conduct a bold and daring experiment to address this puzzle. For 10 consecutive days, Hubble stared at one tiny, seemingly empty patch of sky for 1 million seconds. The gamble of precious telescope time paid off. Hubble captured the feeble glow of myriad never-before-seen galaxies. Many of the galaxies are so far away it has taken billions of years for their light to reach us. Therefore, the view is like looking down a "time corridor," where galaxies can be seen as they looked billions of years ago. Hubble became astronomy's ultimate time machine. …
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There is something wrong with our universe. Or, more specifically, it is outpacing all expectations for its present rate of expansion. Something is amiss in astronomers' efforts to measure the past and predict the present, according to a discrepancy between the two main techniques for measuring the universe's expansion rate – a key to understanding its history and physical parameters. The inconsistency is between the Hubble Space Telescope measurements of today's expansion rate of the universe (by looking at stellar milepost markers) and the expansion rate as measured by the European Space Agency's Planck satellite. Planck observes the conditions of the early universe…
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This Hubble image shows the results of two stellar companions in a gravitational waltz, several thousand light-years from Earth in the southern constellation Centaurus. The stellar duo, consisting of a red giant and white dwarf, are too close together to see individually in this view. But the consequences of their whirling about each other are two vast shells of gas expanding into space like a runaway hot air balloon. Both stars are embedded in a flat disk of hot material that constricts the outflowing gas so that it only escapes away above and below the stars. This apparently happens in episodes because the nebula has two distinct nested hourglass-shaped structures. The …
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NASA has selected 24 new Fellows for its prestigious NASA Hubble Fellowship Program (NHFP). The program enables outstanding postdoctoral scientists to pursue independent research in any area of NASA Astrophysics, using theory, observation, experimentation, or instrument development. Each fellowship provides the awardee up to three years of support. View the full article
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Astronomers once thought asteroids were boring, wayward space rocks that simply orbit around the Sun. These objects were dramatically presented only in science fiction movies. But recent observations show that asteroids are anything but dull. In reality they are dynamic, active worlds that can ultimately disintegrate due to the long-term subtle effects of sunlight, which can slowly spin them up until they begin to shed material. Several telescopes, including NASA's Hubble Space Telescope, have caught the gradual self-destruction of the asteroid (6478) Gault. Images from Hubble show two narrow, comet-like tails of dusty debris streaming from the diminutive asteroid. …
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We live in a gigantic star city. Our Milky Way galaxy contains an estimated 200 billion stars. But that's just the bare tip of the iceberg. The Milky Way is surrounded by vast amounts of an unknown material called dark matter that is invisible because it doesn't release any radiation. Astronomers know it exists because, dynamically, the galaxy would fly apart if dark matter didn't keep a gravitational lid on things. Still, astronomers would like to have a precise measure of the galaxy's mass to better understand how the myriad galaxies throughout the universe form and evolve. Other galaxies can range in mass from around a billion solar masses to 30 trillion solar masses…
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NASA has recovered the Hubble Space Telescope's Advanced Camera for Surveys instrument, which suspended operations on Thursday, Feb. 28, 2019. The final tests were conducted and the instrument was brought back to its operational mode on March 6. View the full article
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At 8:31 p.m. EST on February 28, 2019, the Advanced Camera for Surveys (ACS) aboard NASA's Hubble Space Telescope suspended operations after an error was detected as the instrument was performing a routine boot procedure. The error indicated that software inside the camera had not loaded correctly. A team of instrument system engineers, flight software experts, and flight operations personnel quickly organized to download and analyze instrument diagnostic information. This team is currently working to identify the root cause and then to construct a recovery plan. View the full article
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The phrase "a chip off the old block" apparently also applies to the outer moons of our solar system. A tiny moon whirling around Neptune that was uncovered in Hubble Space Telescope photographs taken in 2013 has puzzled astronomers ever since then because it is very close to a much larger moon named Proteus. The orbits of the two moons are presently 7,500 miles apart. Proteus, at 260 miles in diameter, is roughly the size of the state of Ohio. By contrast, Hippocamp is just 20 miles across, or the size of metropolitan Columbus, Ohio. Proteus should have gravitationally swept aside or swallowed the moon while clearing out its orbital path. Smoking-gun evidence for H…
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The two major planets beyond Saturn have only been visited once by a spacecraft, albeit briefly. NASA's Voyager 2 spacecraft swung by Uranus in 1986, and Neptune in 1989. Our robotic deep-space tourist snapped the only close-up, detailed images of these monstrous worlds. For Neptune, the images revealed a planet with a dynamic atmosphere with two mysterious dark vortices. Uranus, however, appeared featureless. But these views were only brief snapshots. They couldn't capture how the planets' atmospheres change over time, any more than a single snapshot of Earth could tell meteorologists about weather behavior. And, they go through protracted seasonal changes in their multi…
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The universe is very cluttered. Myriad island cities of stars, the galaxies, form a backdrop tapestry. Much closer to home are nebulae, star clusters, and assorted other foreground celestial objects that are mostly within our Milky Way galaxy. Despite the vastness of space, objects tend to get in front of each other. This happened when astronomers used the Hubble Space Telescope to photograph the globular star cluster NGC 6752 (located 13,000 light-years away in our Milky Way's halo). In a celestial game of "Where's Waldo?," Hubble's sharp vision uncovered a never-before-seen dwarf galaxy located far behind the cluster's crowded stellar population. The loner galaxy is i…
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Data from the world's largest digital sky survey is being publicly released today by the Space Telescope Science Institute (STScI) in Baltimore, Maryland, in conjunction with the University of Hawai’i Institute for Astronomy in Honolulu, Hawaii. Data from the Pan-STARRS1 Surveys will allow anyone to access millions of images and use the database and catalogs containing precision measurements of billions of stars and galaxies. This data release contains over 1.6 petabytes of data (a petabyte is one million gigabytes), making it the largest volume of astronomical information ever released. The survey data resides in the Mikulski Archive for Space Telescopes (MAST), which se…
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Two's company and three's a crowd. But thousands are a mosh pit. That's the case in the giant Coma cluster of more than 1,000 galaxies. Hubble spotted a wayward spiral galaxy losing its gas as it plunges toward the center of the massive cluster and is roughed up as it plows through the intergalactic medium. Telltale evidence lies in a long, thin streamer of material that is stretching like taffy from the galaxy's core and on into intergalactic space. Gas is the lifeblood of a galaxy, fueling the birth of new stars. Once it is stripped of all of its gas, the galaxy, named D100, will enter retirement and shine only by the feeble glow of its aging, red stars. D100 is bei…
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The Hubble Space Telescope's Wide Field Camera 3 was brought back to full operational status and completed its first science observations just after noon EST today, Jan. 17, 2019. View the full article
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NASA has moved closer to conducting science operations again with the Hubble Space Telescope's Wide Field Camera 3 instrument, which suspended operations on Tuesday, Jan. 8, 2019. Today, Jan. 15, the instrument was brought back to its operations mode. After resetting the telemetry circuits and associated boards, additional engineering data were collected and the instrument was brought back to operations. All values were normal. Additional calibration and tests will be run over the next 48 to 72 hours to ensure that the instrument is operating properly. Assuming that all tests work as planned, it is expected that the Wide Field Camera 3 will start to collect science images…
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NASA continues to work toward recovering the Hubble Space Telescope’s Wide Field Camera 3 instrument, which suspended operations on Tuesday, January 8. A team of instrument system engineers, Wide Field Camera 3 instrument developers, and other experts formed and quickly began collecting all available telemetry and onboard memory information to determine the sequence of events that caused the values to go out of limits. This team is currently working to identify the root cause and then to construct a recovery plan. If a significant hardware failure is identified, redundant electronics built into the instrument will be used to recover and return it to operations. V…
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