A New Angle on Two Spiral Galaxies for Hubble's 27th Birthday
Hubble Celebrates Its Anniversary with a Spectacular Pair of Galaxies
When the Hubble Space Telescope launched aboard the Space Shuttle Discovery on April 24, 1990, astronomers could only dream what they might see. Now, 27 years and more than a million observations later, the telescope delivers yet another magnificent view of the universe — this time, a striking pair of spiral galaxies much like our own Milky Way. These island cities of stars, which are approximately 55 million light-years away, give astronomers an idea of what our own galaxy would look like to an outside observer. The edge-on galaxy is called NGC 4302, and the tilted galaxy is NGC 4298. Although the pinwheel galaxies look quite different because they are angled at different positions on the sky, they are actually very similar in terms of their structure and contents. (More at Hubble Site)
A Lot of Galaxies Need Guarding in This NASA Hubble View
Power of Massive Galaxy Cluster Harnessed to Probe Remote Galaxies in Early Universe
Like the quirky characters in the upcoming film Guardians of the Galaxy Vol. 2, NASA's Hubble Space Telescope has some amazing superpowers, specifically when it comes to observing galaxies across time and space. One stunning example is galaxy cluster Abell 370, which contains a vast assortment of several hundred galaxies tied together by the mutual pull of gravity. That's a lot of galaxies to be guarding, and just in this one cluster! Photographed in a combination of visible and near-infrared light, the immense cluster is a rich mix of galaxy shapes. Entangled among the galaxies are mysterious-looking arcs of blue light. These are actually distorted images of remote galaxies behind the cluster. These far-flung galaxies are too faint for Hubble to see directly. Instead, the gravity of the cluster acts as a huge lens in space, magnifying and stretching images of background galaxies like a funhouse mirror. Abell 370 is located approximately 4 billion light-years away in the constellation Cetus, the Sea Monster. It is the last of six galaxy clusters imaged in the recently concluded Frontier Fields project — an ambitious, community-developed collaboration among NASA's Great Observatories and other telescopes that harnessed the power of massive galaxy clusters and probed the earliest stages of galaxy development. (More at Hubble Site)
Observatories Combine to Crack Open the Crab Nebula
Colorful New Portrait Shows Energetic Details Embedded in Supernova Remnant
In the summer of the year 1054 AD, Chinese astronomers saw a new "guest star," that appeared six times brighter than Venus. So bright in fact, it could be seen during the daytime for several months. Halfway around the world, Native Americans made pictographs of a crescent moon with the bright star nearby that some think may also have been a record of the supernova.
This "guest star" was forgotten about until 700 years later with the advent of telescopes. Astronomers saw a tentacle-like nebula in the place of the vanished star and called it the Crab Nebula. Today we know it as the expanding gaseous remnant from a star that self-detonated as a supernova, briefly shining as brightly as 400 million suns. The explosion took place 6,500 light-years away. If the blast had instead happened 50 light-years away it would have irradiated Earth, wiping out most life forms.
In the late 1960s astronomers discovered the crushed heart of the doomed star, an ultra-dense neutron star that is a dynamo of intense magnetic field and radiation energizing the nebula. Astronomers therefore need to study the Crab Nebula across a broad range of electromagnetic radiation, from X-rays to radio waves. This composite picture from five observatories captures the complexity of this tortured-looking supernova remnant. (More at Hubble Site)
Hubble Spots Moon Around Third Largest Dwarf Planet
Most of the dwarf planets now have known moons
Beyond the orbit of Neptune lies a frigid, dark, vast frontier of countless icy bodies left over from the solar system's construction 4.6 billion years ago. This region, called the Kuiper Belt, was hypothesized by astronomer Gerard Kuiper in 1951. But it took another four decades for astronomers to confirm its existence. The largest bodies are called dwarf planets, with Pluto being the biggest member. Pluto is so big, in fact, that it was discovered 60 years before other Kuiper worlds were detected. Moons around dwarf planets are elusive, though. Pluto's moon Charon wasn't found until the mid-1970s.
Now, astronomers have uncovered a moon around another dwarf planet by using the combined power of three space observatories, including archival images from the Hubble Space Telescope. Called 2007 OR10, it is the third-largest dwarf planet in the Kuiper Belt. With this moon's discovery, most of the known dwarf planets in the Kuiper Belt larger than 600 miles across have companions. These bodies provide insight into how moons formed in the young solar system. In fact, there is an emerging view that collisions between planetary bodies can result in the formation of moons. Based on moon rock samples from NASA's Apollo mission, astronomers believe that Earth's only natural satellite was born out of a collision with a Mars-sized object 4.4 billion years ago. (More at Hubble Site)
Massive Dying Star Goes Out With a Whimper Instead of a Bang
Every second a star somewhere out in the universe explodes as a supernova. But some super-massive stars go out with a whimper instead of a bang. When they do, they can collapse under the crushing tug of gravity and vanish out of sight, only to leave behind a black hole. The doomed star, named N6946-BH1, was 25 times as massive as our sun. It began to brighten weakly in 2009. But, by 2015, it appeared to have winked out of existence. By a careful process of elimination, based on observations by the Large Binocular Telescope and the Hubble and Spitzer space telescopes, the researchers eventually concluded that the star must have become a black hole. This may be the fate for extremely massive stars in the universe. (More at Hubble Site)
Hubble's Tale of Two Exoplanets: Nature vs. Nurture
Atmospheres of Two Hot Jupiters: Cloudy and Clear
Astronomers once thought that the family of planets that orbit our sun were typical of what would eventually be found around other stars: a grouping of small rocky planets like Earth huddled close to their parent star, and an outer family of monstrous gaseous planets like Jupiter and Saturn.
But ever since the discovery of the first planet around another star (or exoplanet) the universe looks a bit more complicated — if not downright capricious. There is an entire class of exoplanets called "hot Jupiters." They formed like Jupiter did, in the frigid outer reaches of their planetary system, but then changed Zip code! They migrated inward to be so close to their star that temperatures are well over 1,000 degrees Fahrenheit.
Astronomers would like to understand the weather on these hot Jupiters and must tease out atmospheric conditions by analyzing how starlight filters through a planet's atmosphere. If the spectral fingerprint of water can be found, then astronomers conclude the planet must have relatively clear skies that lets them see deep into the atmosphere. If the spectrum doesn't have any such telltale fingerprints, then the planet is bland-looking with a high cloud deck.
Knowing the atmospheres on these distant worlds yields clues to how they formed and evolved around their parent star. In a unique experiment, astronomers aimed the Hubble Space Telescope at two "cousin" hot Jupiters that are similar in several respects. However, the researchers were surprised to learn that one planet is very cloudy, and the other has clear skies. (More at Hubble Site)
Mini-Flares Potentially Jeopardize Habitability of Planets Circling Red Dwarf Stars
Solar flares and associated eruptions can trigger auroras on Earth or, more ominously, damage satellites and power grids. Could flares on cool, red dwarf stars cause even more havoc to orbiting planets, even rendering them uninhabitable? To help answer that question, astronomers sought to find out how many flares such stars typically unleash.
A new study of archival ultraviolet observations from the Galaxy Evolution Explorer (GALEX) spacecraft detected dozens of flares from red dwarf stars. Some flares were weaker than any previously detected. Since smaller flares tend to occur more frequently, these tiny flares might have big implications for planetary habitability. (More at Hubble Site)
Hubble Detects Giant 'Cannonballs' Shooting from Star
Great balls of fire! The Hubble Space Telescope has detected superhot blobs of gas, each twice as massive as the planet Mars, being ejected near a dying star. The plasma balls are zooming so fast through space that they would travel from Earth to the moon in 30 minutes. This stellar "cannon fire" has continued once every 8.5 years for at least the past 400 years, astronomers estimate. The fireballs present a puzzle to astronomers because the ejected material could not have been shot out by the host star, called V Hydrae. The star is a bloated red giant, residing 1,200 light-years away, which has probably shed at least half of its mass into space during its death throes.
The current best explanation is that the plasma balls were launched by an unseen companion star in an elliptical orbit around the red giant. The elongated orbit carries the companion every 8.5 years to within the puffed-up atmosphere of V Hydrae, where it gobbles up material from the bloated star. This material then settles into a disk around the companion, and serves as the launching pad for blobs of plasma, which travel at roughly a half-million miles per hour. This star system could explain a dazzling variety of glowing shapes uncovered by Hubble that are seen around dying stars, called planetary nebulae, researchers say. (More at Hubble Site)
Hubble Reveals Observable Universe Contains 10 Times More Galaxies Than Previously Thought
In Arthur C. Clarke's novel "2001: A Space Odyssey," astronaut David Bowman exclaims, "My God, it's full of stars!" before he gets pulled into an alien-built wormhole in space. When the Hubble Space Telescope made its deepest views of the universe, astronomers might have well exclaimed: "My God, it's full of galaxies!" The Hubble Ultra Deep Field, for example, revealed 10,000 galaxies of various shapes, sizes, colors, and ages, all within an area roughly one-tenth the diameter of the full moon. What's mind-blowing is that these myriad galaxies, though plentiful, may represent merely 10 percent of the universe's total galaxy population. That's according to estimates from a new study of Hubble's deep-field surveys. The study's authors came to the staggering conclusion that at least 10 times more galaxies exist in the observable universe than astronomers thought.
According to the authors, the missing 90 percent of the universe's galaxies are too faint and too far away to be detected by the current crop of telescopes, including Hubble. To uncover them, astronomers will have to wait for much larger and more powerful future telescopes. The researchers arrived at their result by painstakingly converting Hubble deep-field images into 3-D pictures so they could make accurate measurements of the number of galaxies at different epochs in the universe's history. (More at Hubble Site)
STScI Appoints Head of Newly Created Data Science Mission Office
Dr. Arfon Smith has been selected to lead the newly created Data Science Mission Office at the Space Telescope Science Institute (STScI) in Baltimore, Maryland. The Data Science Mission Head is responsible for maximizing the scientific returns from a huge archive containing astronomical observations from 17 space astronomy missions and ground-based observatories.
Since 2013, Smith has been a project scientist and program manager at GitHub, Inc., the world's largest platform for open source software. His duties included working to develop innovative strategies for sharing data and software in academia. Smith also helped to define GitHub's business strategy for public data products, and he played a key role in establishing the company's first data science and data engineering teams. (More at Hubble Site)
In writer Edgar Allan Poe's short story "The Tell-Tale Heart," a killer confesses his crime after he thinks he hears the beating of his victim's heart. The heartbeat turns out to be an illusion. Astronomers, however, discovered a real "tell-tale heart" in space, 6,500 light-years from Earth. The "heart" is the crushed core of a long-dead star, called a neutron star, which exploded as a supernova and is now still beating with rhythmic precision. Evidence of its heartbeat are rapid-fire, lighthouse-like pulses of energy from the fast-spinning neutron star. The stellar relic is embedded in the center of the Crab Nebula, the expanding, tattered remains of the doomed star.
The nebula was first identified in 1731 and named in 1844. In 1928, Edwin Hubble linked the nebula to a supernova first witnessed in the spring of 1054 A.D. Now, the eerie glow of the burned-out star reveals itself in this new Hubble Space Telescope snapshot of the heart of the Crab Nebula. The green hue, representative of the broad color range of the camera filter used, gives the nebula a Halloween theme. (More at Hubble Site)
Dr. Laurent Pueyo Receives 2016 Outstanding Young Scientist Award
The Maryland Academy of Sciences has selected Dr. Laurent Pueyo of the Space Telescope Science Institute (STScI) in Baltimore, Maryland, as the recipient of the 2016 Outstanding Young Scientist award. He will receive the award in a ceremony on Nov. 16 at the Maryland Science Center, located in Baltimore's Inner Harbor.
Pueyo joined STScI in 2013 as an associate astronomer after spending three years as a Sagan Fellow at Johns Hopkins University in Baltimore. His duties at STScI include working on improving the extrasolar-planet imaging capabilities of NASA's James Webb Space Telescope, scheduled to launch in late 2018. The STScI astronomer was a member of the team, led by STScI's Remi Soummer, that discovered that three planets around the nearby star HR 8799 had been hiding in plain sight since 1998 in archival images taken by Hubble's Near Infrared Camera and Multi-Object Spectrometer. (More at Hubble Site)
STScI Astronomers Nancy Levenson and David Soderblom Elected AAAS Fellows
Nancy A. Levenson and David R. Soderblom of the Space Telescope Science Institute (STScI) in Baltimore, Maryland, have been named Fellows of the American Association for the Advancement of Science (AAAS). Election as an AAAS Fellow is an honor bestowed upon AAAS members by their peers.
The AAAS cited Dr. Levenson for her exemplary service and distinguished contributions to the field of astrophysics as Deputy Director of the international Gemini Observatory in La Serena, Chile. She is currently STScI's Deputy Director. Soderblom is cited by the AAAS for his distinguished work in the field of astrophysics, with contributions to understanding low-mass stars and exoplanet searches. An Astronomer at STScI since 1984, Soderblom is also a Principal Research Scientist at Johns Hopkins University in Baltimore. In honor of their efforts, Levenson, Soderblom, and the 389 other newly elected Fellows will receive an official certificate and a gold and blue (representing science and engineering, respectively) rosette pin on February 18, 2017, at the AAAS Fellows Forum during the 2017 AAAS annual meeting in Boston, Massachusetts. For more information about this announcement, visit News. (More at Hubble Site)
Space Telescope Science Institute to Host Data from World's Largest Digital Sky Survey
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 Hawaii 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. The four years of data comprise 3 billion separate sources, including stars, galaxies, and various other objects. The immense collection contains 2 petabytes of data, which is equivalent to one billion selfies, or one hundred times the total content of Wikipedia. (More at Hubble Site)
Festive Nebulas Light Up Milky Way Galaxy Satellite
Two glowing nebulas in the Small Magellanic Cloud, a dwarf galaxy that is a satellite of our Milky Way galaxy, have been observed by NASA's Hubble Space Telescope. Young, brilliant stars at the center of each nebula are heating hydrogen, causing these clouds of gas and dust to glow red. The image is part of a study called Small Magellanic Cloud Investigation of Dust and Gas Evolution (SMIDGE). Astronomers are using Hubble to probe the Milky Way satellite to understand how dust is different in galaxies that have a far lower supply of heavy elements needed to create dust. (More at Hubble Site)
Galaxies Shine with the Brilliance of up to 100 Trillion Suns
Astronomers were fascinated in the 1980s with the discovery of nearby dust-enshrouded galaxies that glowed thousands of times brighter than our Milky Way galaxy in infrared light. Dubbed ultra-luminous infrared galaxies, they were star-making factories, churning out a prodigious amount of stars every year. What wasn't initially clear was what powered these giant infrared light bulbs. Observations by the Hubble Space Telescope helped astronomers confirm the source of the galaxies' light output. Many of them reside within "nests" of galaxies engaged in multiple pile-ups of three, four or even five galaxies. The dust is produced by the firestorm of star birth, which glows fiercely in infrared light.
Now Hubble is illuminating the bright galaxies' distant dust-enshrouded cousins. Boosted by natural magnifying lenses in space, Hubble has captured unique close-up views of the universe's brightest infrared galaxies. The galaxies are ablaze with runaway star formation, pumping out more than 10,000 new stars a year. This unusually rapid star birth is occurring at the peak of the universe's star-making boom more than 8 billion years ago. The star-birth frenzy creates lots of dust, which enshrouds the galaxies, making them too faint to detect in visible light. But they glow fiercely in infrared light, shining with the brilliance of 10 trillion to 100 trillion suns.
The galaxy images, magnified through a phenomenon called gravitational lensing, reveal a tangled web of misshapen objects punctuated by exotic patterns such as rings and arcs. The odd shapes are due largely to the foreground lensing galaxies' powerful gravity distorting the images of the background galaxies. Two possibilities for the star-making frenzy are galaxy collisions or gas spilling into the galaxies. (More at Hubble Site)
Hubble Astronomers Develop a New Use for a Century-Old Relativity Experiment to Measure a White Dwarf's Mass
White dwarf shows how gravity can bend starlight
Albert Einstein reshaped our understanding of the fabric of space. In his general theory of relativity in 1915, he proposed the revolutionary idea that massive objects warp space, due to the effects of gravity. Until that time, Isaac Newton's theory of gravity from two centuries earlier held sway: that space was unchanging. Einstein's theory was experimentally verified four years later when a team led by British astronomer Sir Arthur Eddington measured how much the sun's gravity deflected the image of a background star as its light grazed the sun during a solar eclipse. Astronomers had to wait a century, however, to build telescopes powerful enough to detect this gravitational warping phenomenon caused by a star outside our solar system. The amount of deflection is so small only the sharpness of the Hubble Space Telescope could measure it.
Hubble observed the nearby white dwarf star Stein 2051 B as it passed in front of a background star. During the close alignment, the white dwarf's gravity bent the light from the distant star, making it appear offset by about 2 milliarcseconds from its actual position. This deviation is so small that it is equivalent to observing an ant crawl across the surface of a quarter from 1,500 miles away. (More at Hubble Site)
This stellar swarm is M80 (NGC 6093), one of the densest of the 147 known globular star clusters in the Milky Way Galaxy. Located about 28,000 light-years from Earth, M80 contains hundreds of thousands of stars, all held together by their mutual gravitational attraction.
Globular clusters are particularly useful for studying stellar evolution, since all of the stars in the cluster have the same age (about 15 billion years), but cover a range of stellar masses. Every star visible in this image is either more highly evolved than, or in a few rare cases more massive than, our own Sun. Especially obvious are the bright red giants, which are stars similar to the Sun in mass that are nearing the ends of their lives. (More at Hubble Site)
Icy Moons, Galaxy Clusters, and Distant Worlds Among Selected Targets for James Webb Space Telescope
Webb Telescope Guaranteed Time Observations Targets Announced
Mission officials for NASA’s James Webb Space Telescope announced some of the science targets the telescope will observe following its launch and commissioning. These specific observations are part of a program of Guaranteed Time Observations (GTO), which provides dedicated time to the scientists that helped design and build the telescope’s four instruments. The broad spectrum of initial GTO observations will address all of the science areas Webb is designed to explore, from first light and the assembly of galaxies to the birth of stars and planets. Targets will range from the solar system’s outer planets (Jupiter, Saturn, Uranus, and Neptune) and icy Kuiper Belt to exoplanets to distant galaxies in the young universe. (More at Hubble Site)
Hubble Captures Massive Dead Disk Galaxy that Challenges Theories of Galaxy Evolution
Young, Dead, Compact, Disk Galaxy Surprises Astronomers, Offers New Clues to How Modern-Day Elliptical Galaxies Formed
Astronomers combined the power of a “natural lens” in space with the capability of NASA’s Hubble Space Telescope to make a surprising discovery—the first example of a compact yet massive, fast-spinning, disk-shaped galaxy that stopped making stars only a few billion years after the big bang. Researchers say that finding such a galaxy so early in the history of the universe challenges the current understanding of how massive galaxies form and evolve. Astronomers expected to see a chaotic ball of stars formed through galaxies merging together. Instead, they saw evidence that the stars were born in a pancake-shaped disk. The galaxy, called MACS 2129-1, is considered “dead” because it is no longer making stars. This new insight is forcing astronomers to rethink their theories of how galaxies burn out early on and evolve into local elliptical-shaped galaxies. “Perhaps we have been blind to the fact that early ‘dead’ galaxies could in fact be disks, simply because we haven’t been able to resolve them,” said study leader Sune Toft of the Dark Cosmology Center at the Niels Bohr Institute, University of Copenhagen. (More at Hubble Site)
