Astronomy and Stars
Discussions about astronomy and stars. As we look further out what can we find in the universe beyond Earth's atmosphere?
2,186 topics in this forum
-
- 0 replies
- 551 views
When some people get in the kitchen, they create a delicious meal but leave behind a chaotic mess of splattered food and dirty dishes. Cosmic cookery can be just as messy. While a star can create chemical elements as heavy as iron within its core, anything heavier needs a more powerful source like a stellar explosion or the collision of two neutron stars. Colliding neutron stars can yield gold, plutonium, and a variety of other elements. Theoretically, they also generate gravitational waves as they spiral together at breakneck speed before merging. The first gravitational wave signal from a neutron star merger was detected on August 17. It was accompanied by gamma rays …
Last reply by HubbleSite, -
- 0 replies
- 613 views
A solitary frozen traveler has been journeying for millions of years toward the heart of our planetary system. The wayward vagabond, a city-sized snowball of ice and dust called a comet, was gravitationally kicked out of the Oort Cloud, its frigid home at the outskirts of the solar system. This region is a vast comet storehouse, composed of icy leftover building blocks from the construction of the planets 4.6 billion years ago. The comet is so small, faint, and far away that it eluded detection. Finally, in May 2017, astronomers using the Panoramic Survey Telescope and Rapid Response System (Pan-STARRS) in Hawaii spotted the solitary intruder at a whopping 1.5 billion …
Last reply by HubbleSite, -
- 0 replies
- 655 views
Astronomers categorize the minor bodies in the solar system according to their location and physical composition. Comets are a loose collection of ice and dust that fall in toward the Sun from beyond the orbits of the major planets, and grow long tails of dust and gas along the way. Asteroids are rocky or metallic and are relegated to a zone between Mars and Jupiter. But nature isn't that tidy. The Hubble Space Telescope photographed a pair of asteroids orbiting each other that have a tail of dust, which is definitely a comet-like feature. The odd object, called 2006 VW139/288P, is the first known binary asteroid that is also classified as a main-belt comet. Roughly 5,000…
Last reply by HubbleSite, -
- 0 replies
- 545 views
Don't go looking for the proverbial black cat eating licorice in a coal bin on the planet WASP-12b. Twice the size of any planet found in our solar system, the world is as black as fresh asphalt. Unlike other planets in its class, WASP-12b has the unique capability to trap at least 94 percent of the visible starlight falling into its atmosphere. The temperature of the atmosphere is a seething 4,600 degrees Fahrenheit, which prevents the formation of reflective clouds on the day side. The planet orbits so close to its host that it is tidally locked, which means that it keeps the same side always facing the star. The exoplanet isn't dining alone. Its host star is also …
Last reply by HubbleSite, -
- 0 replies
- 499 views
Only when we fly in a commercial jet at an altitude of about 33,000 feet do we enter Earth's stratosphere, a cloudless layer of our atmosphere that blocks ultraviolet light. Astronomers were fascinated to find evidence for a stratosphere on a planet orbiting another star. As on Earth, the planet's stratosphere is a layer where temperatures increase with higher altitudes, rather than decrease. However, the planet (WASP-121b) is anything but Earth-like. The Jupiter-sized planet is so close to its parent star that the top of the atmosphere is heated to a blazing 4,600 degrees Fahrenheit (2,500 degrees Celsius), hot enough to rain molten iron! This new Hubble Space Telescope …
Last reply by HubbleSite, -
- 0 replies
- 604 views
While photographing Mars, NASA’s Hubble Space Telescope captured a cameo appearance of the tiny moon Phobos on its trek around the Red Planet. Discovered in 1877, the diminutive, potato-shaped moon is so small that it appears star-like in the Hubble pictures. Phobos orbits Mars in just 7 hours and 39 minutes, which is faster than Mars rotates. The moon’s orbit is very slowly shrinking, meaning it will eventually shatter under Mars’ gravitational pull, or crash into the planet. Hubble took 13 separate exposures over 22 minutes to create a time-lapse video showing the moon’s orbital path. View the full article
Last reply by HubbleSite, -
- 0 replies
- 534 views
When the universe was young, stars formed at a much higher rate than they do today. By peering across billions of light-years of space, Hubble can study this early era. But at such distances, galaxies shrink to smudges that hide key details. Astronomers have teased out those details in one distant galaxy by combining Hubble’s sharp vision with the natural magnifying power of a gravitational lens. The result is an image 10 times better than what Hubble could achieve on its own, showing dense clusters of brilliant, young stars that resemble cosmic fireworks. View the full article
Last reply by HubbleSite, -
- 0 replies
- 600 views
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” b…
Last reply by HubbleSite, -
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 gravita…
Last reply by HubbleSite, -
- 0 replies
- 517 views
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 fi…
Last reply by HubbleSite, -
- 0 replies
- 590 views
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. …
Last reply by HubbleSite, -
- 0 replies
- 532 views
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…
Last reply by HubbleSite, -
- 0 replies
- 605 views
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…
Last reply by HubbleSite, -
- 0 replies
- 639 views
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 u…
Last reply by HubbleSite, -
- 0 replies
- 587 views
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 a…
Last reply by HubbleSite, -
- 0 replies
- 544 views
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 galax…
Last reply by HubbleSite, -
- 0 replies
- 606 views
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 differen…
Last reply by HubbleSite, -
- 0 replies
- 578 views
When Galileo discovered Jupiter's moon Europa in 1610, along with three other satellites whirling around the giant planet, he could have barely imagined it was such a world of wonder. This revelation didn't happen until 1979, when NASA's Voyager 1 and 2 flew by Jupiter and found evidence that Europa's interior, encapsulated under a crust of ice, has been kept warm over billions of years. The warmer temperature is due to gravitational tidal forces that flex the moon's interior — like squeezing a rubber ball — keeping it warm. At the time, one mission scientist even speculated that the Voyagers might catch a snapshot of geysers on Europa. Such activity turned out to be …
Last reply by HubbleSite, -
- 0 replies
- 523 views
Named after the Roman king of the gods, the immense planet Jupiter is undoubtedly king of the solar system. Containing more mass than all the other planets combined, Jupiter's immense gravitational field deflects wayward comets that otherwise might slam into Earth, wreaking havoc. This dazzling Hubble Space Telescope photo of Jupiter was taken when it was comparatively close to Earth, at a distance of 415 million miles. Hubble reveals the intricate, detailed beauty of Jupiter's clouds as arranged into bands of different latitudes, known as tropical regions. These bands are produced by air flowing in different directions at various latitudes. Lighter colored areas, calle…
Last reply by HubbleSite, -
- 0 replies
- 615 views
Of all the varieties of exploding stars, the ones called Type Ia are perhaps the most intriguing. Their predictable brightness lets astronomers measure the expansion of the universe, which led to the discovery of dark energy. Yet the cause of these supernovae remains a mystery. Do they happen when two white dwarf stars collide? Or does a single white dwarf gorge on gases stolen from a companion star until bursting? If the second theory is true, the normal star should survive. Astronomers used NASA's Hubble Space Telescope to search the gauzy remains of a Type Ia supernova in a neighboring galaxy called the Large Magellanic Cloud. They found a sun-like star that showed s…
Last reply by HubbleSite, -
- 0 replies
- 530 views
NASA has selected 28 Fellows for its prestigious Einstein, Hubble, and Sagan fellowships. Each post-doctoral fellowship provides three years of support to awardees to pursue independent research in astronomy and astrophysics. The new Fellows will begin their programs in the fall of 2017 at a host university or research center of their choosing in the United States. View the full article
Last reply by HubbleSite, -
- 0 replies
- 532 views
Normally, hefty black holes anchor the centers of galaxies. So researchers were surprised to discover a supermassive black hole speeding through the galactic suburbs. Black holes cannot be observed directly, but they are the energy source at the heart of quasars — intense, compact gushers of radiation that can outshine an entire galaxy. NASA's Hubble Space Telescope made the discovery by finding a bright quasar located far from the center of the host galaxy. Researchers estimate that it took the equivalent energy of 100 million supernovas exploding simultaneously to jettison the black hole. What could pry this giant monster from its central home? The most plausible expl…
Last reply by HubbleSite, -
- 0 replies
- 631 views
In the 1400s, two power struggles were taking place quadrillions of miles apart. In England, two rival branches of the royal House of Plantagenet were battling each other for control of the country's throne. And, in a nebula far, far away, a cluster of stars was waging a real-life star wars, with the stellar members battling each other for supremacy in the Orion Nebula. The gravitational tussle ended with the system breaking apart and at least three stars being ejected in different directions. Astronomers spotted two of the speedy, wayward stars over the past few decades. They traced both stars back 540 years to the same location and suggested they were part of a now-de…
Last reply by HubbleSite, -
- 0 replies
- 1k views
About 6 million years ago, when our very remote ancestors began to evolve away from chimpanzees, our Milky Way galaxy's hefty black hole was enjoying a sumptuous feast. It gulped down a huge clump of interstellar hydrogen. Now, eons later, we see the result of the black hole feast. The black hole "burped" hot plasma that is now towering far above and below the plane of our galaxy. These invisible bubbles, weighing the equivalent of millions of suns, are called the Fermi Bubbles. Their energetic gamma-ray glow was first discovered in 2010 by NASA's Fermi Gamma-ray Space Telescope. (Enrico Fermi was an Italian physicist who created the world's first nuclear reactor.) As…
Last reply by HubbleSite, -
- 0 replies
- 543 views
Twenty years ago, astronauts on the second servicing mission to the Hubble Space Telescope installed the Space Telescope Imaging Spectrograph (STIS) aboard Hubble. This pioneering instrument combines a camera with a spectrograph, which provides a "fingerprint" of a celestial object's temperature, chemical composition, density, and motion. STIS also reveals changes in the evolving universe and leads the way in the field of high-contrast imaging. The versatile instrument is sensitive to a wide range of wavelengths of light, from ultraviolet through the optical and into the near-infrared. From studying black holes, monster stars, and the intergalactic medium, to analyzing th…
Last reply by HubbleSite,