Revealing the youthful glow of blue star clusters and a dusty core hidden from view
Space news (astrophysics: giant elliptical galaxies; Centaurus A) – 11 million light-years from Earth toward the constellation Centaurus (NGC 5128) –
The closest galaxy to Earth with an active nucleus containing a supermassive black hole that ejects jets of high-speed, extremely energetic particles into space, the giant elliptical island universe Centaurus A’s (NGC 5128) a nearby laboratory in which astronomers test present theories.
The stunning Hubble Space Telescope image of Centaurus A (above) reveals a scene resembling cosmic clouds on a stormy day. Dark lanes of gas and dust crisscross its warped disk, revealing the youthful glow of blue star clusters, and red patches indicating shockwaves from a recent merger with a spiral galaxy. Shockwaves that cause hydrogen gas clouds to contract, starting the process of new star formation.
The startling composite image of Centaurus A above combines X-ray data from NASA’s Chandra Observatory, optical data from the European Southern Observatory’s Very Large Telescope, and the National Radio Astronomy Observatory’s Very Large Array. The core of NGC 5128 is a mess of gas, dust, and stars in visible light, but X-rays and radio waves reveal a stunning jet of high-speed, extremely energetic particles emanating from its active nucleus.
What could power such an event?
The power source for the relativistic jets observed streaming from the active galactic nucleus of Centaurus A’s a supermassive black hole with the estimated mass of over 10 million suns. Beaming out from the galactic nucleus toward the upper left, the high-speed jet travels nearly 13,000 light-years, while a shorter jet shoots from the core in the opposing direction. Astronomers think the source of the chaos in active galaxy Centaurus A’s the noted collision with a spiral galaxy about 100 million years ago.
The amazing high-energy, extremely-fast, 30,000 light-year-long particle jet is the most striking feature in the false-color X-ray image taken by the Chandra Observatory. Beaming upward toward the left corner of the image, the relativistic jet seems to blast from the core of Centaurus A. A core containing an active, monster black hole pulling nearby matter into the center of its gravity well. An unknown realm mankind dreams about visiting one day.
You can learn more about supermassive black holes here.
Traveling at 250,000 mph would be a windy, visually spectacular ride to hell
Space news (Astrophysics: stellar nursery dynamics; runaway stars) – 170,000 light-years from Earth, near the edge of the Tarantula Nebula –
If you want to travel through the galaxy, hitch a ride on a runaway star like the one astronomers have been tracking since it came screaming out of 30 Doradus (Tarantula Nebula) in 2006. Data collected by the newly installed Cosmic Origins Spectrograph on the Hubble Space Telescope suggests a massive star, as much as 90 times the mass of Sol, was knocked out of the nebula by gravitational interactions with even more massive suns. Traveling at around 250,000 mph, voyaging through the cosmos on this runaway star would be an adventure to write home about.
The trail leads back to a star-forming region deep within the Tarantula Nebula called R136, where over 2,400 massive stars near the center of this huge nebula produce an intense wind of radiation. Astronomers think interactions with some of the 100 plus solar mass stars detected in this stellar nursery resulted in this runaway star being flung over 375 light-years by its bigger siblings.
“These results are of great interest because such dynamical processes in very dense, massive clusters have been predicted theoretically for some time, but this is the first direct observation of the process in such a region,” says Nolan Walborn of the Space Telescope Science Institute in Baltimore and a member of the COS team that observed the misfit star. “Less massive runaway stars from the much smaller Orion Nebula Cluster were first found over half a century ago, but this is the first potential confirmation of more recent predictions applying to the most massive young clusters.”
Astrophysicists studying the runaway star and the region in the Tarantula region where the trail ended believe it’s likely a massive, blue-white sun at least ten times hotter than Sol and only a few million years old. It’s far from home and in a region of space where no clusters with similar stars are found. It’s also left an egg-shaped cavity in its wake with glowing edges pointing in the direction of the center of 30 Doradus and the region of R136. A flaming trail you would see behind the star as you traveled across the cosmos and onto eternity.
“It is generally accepted, however, that R136 is sufficiently young, 1 million to 2 million years old, that the cluster’s most massive stars have not yet exploded as supernovae,” says COS team member Danny Lennon of the Space Telescope Science Institute. “This implies that the star must have been ejected through dynamical interaction.”
This runway star continues to scream across the cosmos, nearing the outskirts of 30 Doradus a star-forming region in the Large Magellanic Cloud, it will one day end its existence in a titanic explosion or supernova, and possibly leave behind one of the most mysterious and enigmatic objects discovered during the human journey to the beginning of space and time, a black hole.
Imagine riding this runaway star until it contracted into a black hole and left our universe altogether. Where would we travel? To a random location in spacetime? To another reality or universe? The possibilities abound and far exceed our ability to imagine such a reality. Scientists tell us such a journey wouldn’t be possible, but they’re just stumbling around in the dark looking for ideas to grasp. For handholds on the dark cliff we climb as we search for answers to the mysteries before us.
Astronomers continue to study the Tarantula Nebula and the star-forming region R136 looking for signs of impending supernovae among the zoo of supermassive stars within. They also continue to track this runaway star and two other blue hot, supermassive stars outside the boundary of 30 Doradus that appear to have also been ejected from their host systems. We’ll update you with any news on it, and other runaway stars as it continues to scream across the cosmos.
A frosty, chilly star about the same temperature as the North Pole, minus 54 and 9 degrees Fahrenheit (minus 48 to minus 13 degrees Celsius)
Space news (astrophysics: faint, cool stars; brown dwarfs) – the fourth closest detected star system to Earth, just 7.2 light-years toward the constellation Hydra –
A young, ambitious astronomer working at Pennsylvania State University’s Center for Exoplanets and Habitable Worlds discovered the dimmest, coolest brown dwarf detected during the human journey to the beginning of space and time. Kevin Lehman first noticed a fast moving object, quickly dubbed WISE J085510.83-071442.5, in March of 2013. Excited at a new discovery, he spent the next few days analyzing more images of the same part of the sky taken by NASA’s Spitzer Space Telescope and Gemini South Telescope on Cerro Pachon in Chile.
“It’s very exciting to discover a new neighbor of our solar system that is so close,” said Kevin Luhman, an astronomer at Pennsylvania State University’s Center for Exoplanets and Habitable Worlds, University Park. “And given its extreme temperature, it should tell us a lot about the atmospheres of planets, which often have similarly cold temperatures.”
Kevin Luhman originally spotted the fast motion of WISE J085510.83-071442.5 in infrared images taken by NASA’s Wide-field Infrared Survey Explorer (WISE). Later analysis of infrared images taken by NASA’s Spitzer Space Telescope were needed to determine its chilly temperature of between minus (54-9) Fahrenheit [minus (13 – 48) degrees Celsius]. Astronomers would use measurements taken by Spitzer and WISE at different positions around the sun to determine its distance of 7.2 light-years from Earth using the parallax effect. To scientists, it added up to a brown dwarf or maybe a large Jupiter-size planet lost in space.
“This object appeared to move really fast in the WISE data,” said Luhman. “That told us it was something special.”
Additional calculations estimated the mass of WISE J085510.83-071442.5 at between 3 and 10 times the mass of Jupiter. It could be a gas giant like Jupiter that was flung out of its host star system by gravitational interactions with more massive bodies. Astronomers determined it was more likely a very cool brown dwarf than a large gas giant planet since they have been detected more often. If this is the case, it’s the coldest brown dwarf star discovered during the human journey to the beginning of space and time. A nice shiny feather in the hat of a young, aspiring astronomer on the rise.
“It is remarkable that even after many decades of studying the sky, we still do not have a complete inventory of the sun’s nearest neighbors,” said Michael Werner, the project scientist for Spitzer at NASA’s Jet Propulsion Laboratory in Pasadena, Calif. JPL manages and operates Spitzer. “This exciting new result demonstrates the power of exploring the universe using new tools, such as the infrared eyes of WISE and Spitzer.”
Work’s never done
Never one to rest on his laurels, in March of 2013, Kevin Luhman discovered a pair of warmer brown dwarf stars just 6.5 light-years from Earth during his analysis of WISE images. Since this time, his search for rapidly moving bodies close to Earth has also shown that the outer solar system probably doesn’t contain a large, undiscovered planet X or Nemesis, as people often refer to it. I did mention he was ambitious.
A very rapidly evolving, supermassive star with a newly formed nebula only a few thousand years old
Space news (supermassive stars: Wolf-Rayet stars; star NaSt1) – 3,000 light-years away on the edge of a pancake-shaped disk of gas moving at 22,000 mph –
Astronomers using the Hubble Space Telescope have discovered new clues concerning a nearby supermassive, rapidly aging star they have nicknamed “Nasty 1”. Designated NaSt1 in astronomy catalogs, “Nasty 1” when first discovered decades ago was identified as a non-typical Wolf-Rayet star with an orbiting disk-like structure. A vast disk estimated to be almost 2 trillion miles wide astronomers now think formed due to a companion star snacking on its outer envelope. Putting NaSt1 in a class of Wolf-Rayet stars astronomers haven’t observed often during the human journey to the beginning of space and time. A star type possibly representing a transition stage in the evolution of supermassive stars.
“We were excited to see this disk-like structure because it may be evidence for a Wolf-Rayet star-forming from a binary interaction,” said study leader Jon Mauerhan of the University of California, Berkeley. “There are very few examples in the galaxy of this process in action because this phase is short-lived, perhaps lasting only a hundred thousand years, while the timescale over which a resulting disk is visible could be only ten thousand years or less.”
In the case of NaSt1, computer simulations show a supermassive star evolving really fast and swelling as it begins to run out of hydrogen. Its outer hydrogen envelope is loosely bound and is gravitationally stripped from the star- astronomers call this process stellar cannibalism – by a more compact, nearby companion star. In the process the more compact star gains mass, while the more massive star loses its hydrogen envelope, exposing its helium core and eventually becoming a Wolf-Rayet star.
The mass-transfer model is the favored process for how Wolf-Rayet stars evolve at the moment and considering at least 70 percent of supermassive stars detected, so far, are members of binary star system, this seems logical. Astronomers used to think this type of star could also form when a massive sun ejects its hydrogen envelope. But the direct mass loss model by itself can’t account for the number of Wolf-Rayet stars observed relative to less-evolved supermassive suns in the Milky Way.
“We’re finding that it is hard to form all the Wolf-Rayet stars we observe by the traditional wind mechanism because the mass loss isn’t as strong as we used to think,” said Nathan Smith of the University of Arizona in Tucson, who is a co-author on the new NaSt1 paper. “Mass exchange in binary systems seems to be vital to account for Wolf-Rayet stars and the supernovae they make, and catching binary stars in this short-lived phase will help us understand this process.”
Astronomers computer models show that the mass-transfer process isn’t always perfectly efficient. Matter can only transfer from NaSt1 at a certain rate, left over material begins orbiting, creating a disk-like structure.
“That’s what we think is happening in Nasty 1,”Mauerhan said. “We think there is a Wolf-Rayet star buried inside the nebula, and we think the nebula is being created by this mass-transfer process. So this type of sloppy stellar cannibalism actually makes Nasty 1 a rather fitting nickname.”
Observing Nasty 1 (star NaSt1) through the clock of gas and dust surrounding this star system hasn’t been easy. The intervening disk-like structure even blocks the view of the Hubble Space Telescope. Scientists haven’t been able to measure the distance between the stars, their mass, or the volume of material transferring to the smaller companion star.
Astronomers have been able to discover a few items concerning the disk-like structure surrounding Nasty 1. Measurements indicate it’s traveling at around 22,000 mph in the outer nebula, a slower speed than recorded in other stars of this type. Scientists think this indicates a much less energetic supernova than was recorded for other events, like Era Carinae. In this case and other similar stars, the gas in the outer nebula has been recorded in the hundreds of thousands of miles per hour. Nasty 1 could be different supernova animal altogether.
Nasty 1 could also lose its outer envelope of hydrogen intermittently. Previous studies in the infrared light provided clues indicating the existence of a dense pocket of hot gas and dust close to the central stars in the region. More recent observations using the Magellan Telescope located at the Las Campanas Observatory in Chile has also detected a bigger pocket of cooler gas and dust possibly indirectly blocking light from these stars. Astronomers think the existence of warm dust in the region implies it formed just recently, perhaps intermittently, as elementally enriched matter from the stellar winds of massive stars collides, mixes, flows away, and cools. Irregular stellar wind strength, the rate at which star NaSt1 loses its outer envelope, could also help explain the observed clumpy structure and gaps noted in the outer regions of the disk.
Astrophysicists used NASA’s Chandra X-ray Observatory to measure the hypersonic winds screaming from each star. Readings showed a scorching hot plasma, indicating colliding stellar winds producing high-energy shockwaves that glow in X-rays. This is consistent with previous data collected on other evolving Wolf-Rayet star systems. We’ll get a better view once the outer hydrogen of Nasty 1’s (star NaSt1) depleted, and the mass-transfer process completes. Eventually, the gas and dust in the lumpy, disk-like structure will dissipate, giving us a clearer view of this mysterious binary star system.
Nasty 1’s still evolving!
“What evolutionary path the star will take is uncertain, but it will definitely not be boring,” said Mauerhan. “Nasty 1 could evolve into another Eta Carinae-type system. To make that transformation, the mass-gaining companion star could experience a giant eruption because of some instability related to the acquiring of matter from the newly formed Wolf-Rayet. Or, the Wolf-Rayet could explode as a supernova. A stellar merger is another potential outcome, depending on the orbital evolution of the system. The future could be full of all kinds of exotic possibilities depending on whether it blows up or how long the mass transfer occurs, and how long it lives after the mass transfer ceases.”
Astronomers continue to study Nasty 1 and its peculiar, unusual disk-like structure looking for clues to explain the mysteries surrounding its origin.
Join the conversation and learn more about NASA here.
Stone-age Polynesians crisscrossed the Pacific Ocean, populating islands in a deliberate manner, as far back as tens of thousands of years ago using the stars, winds, currents, waves and other natural phenomena as guides
Ancient astronomy – When Europeans first sailed across the Pacific Ocean in the 1500s, they made an amazing discovery. Stone-age people as far back as tens of thousands of years ago had found their way to small, scattered islands spread across an immense body of water covering three-quarters of the surface of Earth –
Local Polynesian traditions and folklore told of purposeful, long-term voyages of sea-going canoes across hundreds and even thousands of miles of open water. In this way, oral tradition and modern archaeology say groups of Pacific islands were deliberated populated by stone-age Polynesians thousands of years ago.
People intimately connected to the oceanenvironment in which they lived, ancient Polynesian islanders navigated by a precise science passed on orally from generation to generation. They sailed hundreds and even thousands of miles across the dangerous and deep ocean using only the stars, winds, currents and even waves to find their way to small islands scattered across millions of square miles of empty water.
Using natural science Polynesian islanders appear to have settled at least three groups of Pacific Ocean islands. Scientists have definite proof darker skinned people settled one group of islands, named Melanesia (Greek for black islands) by Europeans, stretching eastward from New Guinea to Fiji thousands of years ago. Humans with light-brown skin lived on Micronesia (little islands), north of Melanesia. Tall, pale-skinned people colonized Polynesia (many islands), a sprawling eastern triangle including Hawaii, New Zealand, and isolated Easter Island.
At first, Europeans refused to believe that stone-age people sailed to distant islands without using navigational instruments to plot position and stay on course. In the 1600s sailors noted even experienced Europeans couldn’t determine their position and course once losing sight of land for a few days. This belief concerning the navigational skills of islanders persisted until the end of the 1960s when New Zealand-born adventurer David Lewis discovered Pacific Ocean islanders still made long-distance fishing and trading voyages without modern navigational equipment.
Determined to learn all he could about the old navigational skills and lore of Polynesian islanders before it was totally supplanted by modern tools and techniques, David Lewis made a decision that would provide proof of their ancient navigational skills. During a nine-month period between 1968 – 1969, he journeyed across the West Pacific, sometimes in native canoes using the skills of islanders, other times in a 39-foot gaff ketch stripped of navigational aids. Guided by illiterate, but skillful and confident Polynesian islanders Tevake and Hipour, they traveled across thousands of miles of deep water using the stars, winds, currents, waves and other natural phenomena to guide them. Along the way, they talked at length with sailors from several different Pacific islands, including Tonga where navigational skills and knowledge were once considered family secrets.
In his book, “We, the Navigators” adventurer and explorer David Lewis tells of the navigational skills of Polynesian islanders who still use many of the same directional aids stone-age peoples used to colonize the islands of the Pacific Ocean. How they used guide stars to travel confidently to small islands far beyond the horizon, by simply steering toward a star known to stand above a given destination. Guide stars low in the sky were always selected. When heading east they selected a star that had just risen and one about to fall when sailing west. His islander guides followed a star path to their destination. After one guide star had risen too high or low below the horizon, they would select another that set or rose at the same position in the sky. Using this method, David and his companions made one nighttime journey by sailing a star path of nine guide stars in a row to reach a destination over 70 miles (112 kilometers) across open water.
Hawaiian and Tahitian islanders navigated to various islands hundreds of miles apart using a celestial “star compass” that uses the locations of 32 stars ascending and falling around the horizon at irregular distances apart. Using specific islands called etak (reference) islands for which the shift in apparent position from below one star to another during a journey was already known. An islander navigating from destination A to B would begin by selecting a certain island under star 1 as his etak. As he sailed on, the bearing of island 1 would change until it rested under star 2, the next point on the “star compass”. The navigator would just continue the process until the destination was reached. Through years of intensive, traditional land-based training using the placement of stones to represent star formations and other methods. They memorized various ancient astronomical charts to certain islands and became amazingly capable of reading and interpreting the night sky. Capable enough to pinpoint a ship’s location using only a few stars briefly viewed through an overcast sky.
During the daylight hours, they navigated using the position of the sun in the sky. But his guides didn’t solely rely on the stars and the sun, they had a confident understanding and way of reading the behavior of wind, waves, currents and other natural forces. During one nighttime journey through a storm, the old Polynesian Tevake confidently navigated more than 40 miles (64 kilometers), including bringing the boat expertly between two islands less than half a mile apart. Even when forced off course by a storm or unguided by the winds, stars, waves and other natural forces, navigators like Hipour and Tevake had traditional methods for navigating to unseen islands across vast stretches of the immense Pacific Ocean. For example, they often guided themselves and others toward an unseen island miles away by observing the clouds, which they explained appear slightly different in color and tone depending on the type of land or depth of ocean over which they are sailing. They also interpreted the flight of birds, floating debris or land waves they said can often cause a boat to pitch when over 50 miles (80 kilometers) from the island surf that created them. The most amazing and intriguing guidepost they used is an enigmatic, unexplained natural event referred to in different parts of the Pacific Islands as te lapa, te mata, or ulo aetahi (glory of the sea). Flashing steaks of light just feet below the surface that align with land up to 100 miles away, this “glory of the sea” is a ghostly phosphorescence ancient stone age navigators used to help deliberately and systematically populate the islands of the Pacific Ocean with amazing accuracy as far back as tens of thousands of years ago.
Tells astronomers a thing or two about star birth throughout the cosmos
Space news (astrophysics: irregular dwarf galaxies; the formation of new stars) – a lonely, undefined looking galaxy an estimated 4.2 million light-years from Earth, approximately 2.3 million light-years from Leo A –
Astronomers think the chaotic, unusual looking smaller island universe seen in the Hubble Space Telescope image here hasn’t merged with any other galaxies lately. Classified as an irregular dwarf galaxy, UGC 4879 has no obvious form and lacks the magnificent whirl of a spiral galaxy or the coherence of an elliptical. Approximately 1.36 million parsecs from Earth this lonely, wandering hermit of a galaxy is showing astronomers new, interesting things about star birth in the universe.
Spectral data of UGC 4879 indicates radial velocities for different sections of the galaxy, which could indicate the presence of a stellar disk. This lonely, isolated wanderer is studied closely and intensely by astronomers because of its history of few interactions with other galaxies. This isolation makes it less complicated to piece together its history of star birth and an ideal laboratory for study.
Study of UGC 4879 indicates during the first 4 billion years after the beginning of the universe new stars were being born at a pretty fast rate. The next nine billion years of relative inactivity followed by a recent starburst about 1 billion years ago is a puzzle for astronomers. They continue to study this hermit of a galaxy hoping to find out more about both its history and the complex riddles of sun birth across the cosmos.
The seed out of which some of these mysterious, lurking monsters were born
Space news (astrophysics: black hole formation: early black holes) – supermassive black holes scattered around the observable universe –
Astronomers believe and data suggests at the center of nearly all large galaxies, including the Milky Way, lurks a supermassive black hole with millions and even billions of times the mass of our sun. Gigantic black holes that in some cases formed less than a billion years after the birth of the cosmos. For the first time, they have uncovered evidence suggesting some of these early supermassive black holes formed directly during the collapse of a giant gas cloud. A finding making astronomers rethink current theories on the formation of these enigmatic, invisible monsters.
“Our discovery, if confirmed, explains how these monster black holes were born,” said Fabio Pacucci of Scuola Normale Superiore (SNS) in Pisa, Italy, who led the study. “We found evidence that supermassive black hole seeds can form directly from the collapse of a giant gas cloud, skipping any intermediate steps.”
Intermediate steps like the formation of a supermassive star and its subsequent destruction during a supernova. Evidence to date suggests black holes are formed during this process and then supermassive black holes are produced by mergers between black holes. But this new finding suggests things get a little weirder than first thought. Maybe things are weirder than we could ever imagine. It could be the first supermassive black holes seeds were intermediate mass black holes, monsters in the 20,000 solar mass range. Watch this YouTube video on black hole formation.
Imagine the volume of a gas cloud capable of contracting directly into an object tens times, or more, the mass of Sol. Black hole seeds built up by drawing in cold gas and dust appear to have formed within the first billion years of the cosmos. Maybe once they confirm the existence of the two black hole seeds they think they detected. They can try to get some data on the mass of these early black hole seeds. At the moment, no mass data is available. Watch this YouTube video on black hole seeds.
The forming of a supermassive black hole directly from the collapse of a massive cloud of gas seems even weirder than the observed formation process for supermassive black holes. But we’re not in Kansas anymore, so anything could theoretically be possible. I am certain, things are even weirder than we can imagine.
“There is a lot of controversy over which path these black holes take,” said co-author Andrea Ferrara, also of SNS. “Our work suggests we are narrowing in on an answer, where the black holes start big and grow at the normal rate, rather than starting small and growing at a very fast rate.”
The team used computer models of the formation of black hole seeds combined with new techniques and methods to identify two possible candidates for early supermassive black holes in long-exposure Hubble, Chandra, and Spitzer images. The data collected on these two candidates matches the theoretical profile expected and estimates of their age suggest they formed when the cosmos was less than a billion years old. But more study is needed to verify the data and existence of these theoretical early black hole seeds.
“Black hole seeds are extremely hard to find and confirming their detection is very difficult,” said Andrea Grazian, a co-author from the National Institute for Astrophysics in Italy. “However, we think our research has uncovered the two best candidates to date.”
The team plans additional observations to see if these two candidates have other properties of black hole seeds as computer simulations predict. Real evidence to prove or disprove their early supermassive black hole formation theory might have to wait for a few years. Until the James Webb Space Telescope, European Extremely Large Telescope and other assets come online. The team and other astronomers are currently designing the theoretical framework needed to interpret future data and pinpoint the existence of some of the first supermassive black holes ever to exist. Watch this YouTube video on the jet of Centaurus A.
Read the scientific paper released on the first identification of black hole seeds here.