In order to better understand intricate operations and detailed planning needed to capture multi-ton boulder from asteroid surface
Space news (Asteroid Redirect Mission: testing of prototype of robotic capture module system) – The Robotic Operations Center of NASA’s Goddard Space Flight Center –
Inside the Robotic Operations Center (ROC) of NASA’s Goddard Space Flight Center engineers are at work preparing the robotic section of the Asteroid Redirect Mission (ARM). The most recent work involved testing a prototype of the asteroid capture system with a mock boulderbuilt by NASA and students from West Virginia University. This work will help engineers learn more about the intricate operations needed to capture a multi-ton boulder from the surface of an asteroid. The robotic section of ARM is targeted for a 2021 launch window.
The capability built into the ROC allows engineers to create a simulation of the capture of a boulder from the surface of an asteroid. Here they can also simulate servicing of the satellite, fine tuning of systems and controllers, and even optimize all performance factors for future repairs and refueling. An important capabilitywhen building spacecraft worth hundreds of millions of dollars and even more. One that saves money and time.
The report reflects the findings of a two-month study conducted by members of the Small Bodies Assessment Group (SBAG). It explains many of ARM’s potential contributions to the future of the human journey to the beginning of space and time.
“This report is an important step in identifying ways that ARM will be more scientifically relevant as we continue mission formulation for the robotic and the crew segments,” said Gates. “We’re currently in the process of selecting hosted instruments and payloads for the robotic segment, and hope to receive an updated analysis from the SBAG after we announce those selections in spring 2017.”
Giving us a rare, unique window into the environment and emission history of the strongest magnets in the cosmos
Space news (astrophysics: wind nebulas; Swift J1834.9-0846) – 13,000 light-years toward the constellation Scutum in the midst of a vast cloud of high-energy, particles surrounding supernova remnant W41 –
Astronomers studying the strongest magnets discovered during the human journey to the beginning of space and time, magnetars, have detected one they haven’t seen before.A magnetar, a rare highly magnetic neutron star with a vast cloud of high-energy, recently-emitted particles called a wind nebula streaming from it. Offeringa unique window into the characteristics, environment and emission history of one of the most enigmatic and eye-opening objects ever detected.
“Right now, we don’t know how J1834.9 developed and continues to maintain a wind nebula, which until now was a structure only seen around young pulsars,” said lead researcher George Younes, a postdoctoral researcher at George Washington University in Washington. “If the process here is similar, then about 10 percent of the magnetar’s rotational energy loss is powering the nebula’s glow, which would be the highest efficiency ever measured in such a system.”
An object around 13 miles (20 kilometers) in diameter, or about the length of Manhattan Island, only 29 magnetars have been detected, so far. In this particular case, the source of detected emissionsis called Swift J1834.9-0846, a rare type of ultra-magnetic neutron stardetected by the Swift Gamma-ray Burst Satellite on August 7, 2011. It was subsequently looked at closer a month later by a team led by Younes using the European Space Agency’s (ESA) XMM-Newton X-ray Observatory. It was at this time astronomers realized and confirmed the first wind nebula ever detected around a magnetar.
“For me, the most interesting question is, why is this the only magnetar with a nebula? Once we know the answer, we might be able to understand what makes a magnetar and what makes an ordinary pulsar,” said co-author ChryssaKouveliotou, a professor in the Department of Physics at George Washington University’s Columbian College of Arts and Sciences.
Neutron stars are the crushed cores of massive stars left over after they have gone supernova and the densest objects astrophysicists have been able to directly observe during the human journey to the beginning of space and time. All neutron star magnetic fields detected, so far, are 100 to 10 trillion times stronger than Earth’s, and magnetar fields reach levels thousands of times stronger. Astrophysicists have no ideas on howmagnetic fields of such immense strength are formed.
“Making a wind nebula requires large particle fluxes, as well as some way to bottle up the outflow so it doesn’t just stream into space,” said co-author Alice Harding, an astrophysicist at NASA’s Goddard Space Flight Center in Greenbelt, Maryland. “We think the expanding shell of the supernova remnant serves as the bottle, confining the outflow for a few thousand years. When the shell has expanded enough, it becomes too weak to hold back the particles, which then leak out and the nebula fades away. This naturally explains why wind nebulae are not found among older pulsars, even those driving strong outflows.“
“The nebula around J1834.9 stores the magnetar’s energetic outflows over its whole active history, starting many thousands of years ago,” said team member Jonathan Granot, an associate professor in the Department of Natural Sciences at the Open University in Ra’anana, Israel. “It represents a unique opportunity to study the magnetar’s historical activity, opening a whole new playground for theorists like me.”
Astrophysicists think a magnetar outburst’s powered by energy stored in itssuper-strong magnetic fieldproduced gamma rays and x-rays, along with the gales of accelerated particles making up the nebulawind detected in the case of Swift J1834.9-0846. Now, they have a mystery to figure out, and new theories to deduce to explain the way a magnetar produces anebula wind.
Transform surrounding regions and actively evolve host galaxies
Space news (astrophysics: spinning black holes; bigger, brighter plasma jets) – in the core of galaxies across the cosmos, observing the spin of supermassive black holes –
Have you ever had the feeling the world isn’t the way you see it? That reality’s different than the view your senses offer you? The universe beyond the Earth is vast beyond comprehension and weird in ways human imagination struggles to fathom. Beyond the reach of your senses, the fabric of spacetime warps near massive objects, and even light bends to the will of gravity. In the twilight zone where your senses fear to tread, the cosmos twists and turns in weird directions and appears to leave the universe and reality far behind. Enigmas wrapped in cosmic riddles abound and mysteries to astound and bewilder the human soul are found.
Imagine an object containing the mass of millions even billions of stars like the Sun. Squeeze that matter into a region of infinitely small volume, a region so dense the gravitational force it exerts warps spacetime and prevents even light from escaping its grasp. This object’s what astronomers call a supermassive black hole, a titanic monster your eyes can’t see with a gravitational pull that would stretch your body to infinity as you approached and crossed its outer boundary, the event horizon. Beyond this point, spacetime and reality take a turn toward the extreme, and the rules of science don’t apply. You have entered the realm of one of the most mysterious and enigmatic objects discovered during the human journey to the beginning of space and time.
Astronomers hunting for supermassive black holes have pinpointed their realms to be the center of massive galaxies and even the center of galaxy clusters. From this central location in each galaxy, the gravitational well of each supermassive black hole appears to act as an anchor point for the billions of stars within, and astronomers believe a force for change and evolution of every galaxy and galaxy cluster in which they exist. Surrounded and fed by massive clouds of gas and matter called accretion disks, with powerful particle jets streaming from opposite sides like the death ray in Star Wars, fierce, hot winds sometimes moving at millions of miles per hour blow from these supermassive monsters in all directions.
“A lot of what happens in an entire galaxy depends on what’s going on in the minuscule central region where the black hole lies,” said theoretical astrophysicist David Garofalo of NASA’s Jet Propulsion Laboratory in Pasadena, Calif. Garofalo is the lead author of a new paper that appeared online May 27 in the Monthly Notices of the Royal Astronomical Society. Other authors are Daniel A. Evans of the Massachusetts Institute of Technology, Cambridge, Mass., and Rita M. Sambruna of NASA Goddard Space Flight Center, Greenbelt, Md.
Astronomers studying powerful particle jets streaming from supermassive black holes use to think these monsters spin either in the same direction as their accretion disks, called prograde black holes, or against the flow, retrograde black holes. For the past few decades, Garofalo and team have worked with a theory that the faster the spin of a black hole, the more powerful the particle jets streaming from it. Unfortunately, anomalies in the form of some prograde black holes with no jets have been discovered. This has scientists turning their ideas upside down and sideways, to see if flipping their “spin paradigm” model on its head explains recent anomalies in the theory.
Using data collected during a more recent study that links their previous theory with observations of galaxies at varying distances from Earth across the observable universe. Astronomers found more distant radio-loud galaxies with jets are powered by retrograde black holes, while closer radio-quiet black holes have prograde black holes. The study showed supermassive black holes found at the core of galaxies evolve over time from a retrograde to prograde state.
“This new model also solves a paradox in the old spin paradigm,” said David Meier, a theoretical astrophysicist at JPL not involved in the study. “Everything now fits nicely into place.”
Astrophysicists studying backward spinning black holes believe more powerful particle jets stream from these supermassive black holes because additional space exists between the monster and the inner edge of the accretion disk. This additional space between the monster and accretion disk provides more room for magnetic fields to build-up, which fuels the particle jet and increases its power. This idea is known as Reynold’s Conjecture, after the theoretical astrophysicist Chris Reynolds of the University of Maryland, College Park.
“If you picture yourself trying to get closer to a fan, you can imagine that moving in the same rotational direction as the fan would make things easier,” said Garofalo. “The same principle applies to these black holes. The material orbiting around them in a disk will get closer to the ones that are spinning in the same direction versus the ones spinning the opposite way.”
Scientists believe the powerful particle jets and winds emanating from supermassive black holes found at the center of galaxies also play a key role in shaping their evolution and eventual fate. Often even slowing the formation rate of new stars in a host galaxy and nearby island universes as well.
“Jets transport huge amounts of energy to the outskirts of galaxies, displace large volumes of the intergalactic gas, and act as feedback agents between the galaxy’s very center and the large-scale environment,” said Sambruna. “Understanding their origin is of paramount interest in modern astrophysics.”
What lies just beyond the reach of our senses and technology, beneath the exterior of these supermassive black holes? Scientists presently study these enigmatic stellar objects looking for keys to the doors of understanding beyond the veil of gas and dust surrounding these titanic beasts. Keys they hope one day to use to unlock even greater secrets of reality just beyond hidden doors of understanding.
Produces shocks that accelerate particles, illuminating the colliding material
Space news (astrophysics: relativistic jets; shock collisions inside particle jets) – Observing plasma jet blasting from supermassive black hole in core of galaxy NGC 3862, 260 million light-years from Earth toward the constellation Leo in the rich galaxy cluster Abell 1367 –
Astronomers recently made an interesting discovery while studying data collected by the Hubble Space Telescope over two decades of observing the core of elliptical galaxy NGC 3862. They were originally looking to create a time-lapse video of a relativistic jet blasting from the supermassive black hole thought to reside within its core. Instead, they discovered a rear-end collision between two separate high-speed waves of material ejected by a monster black hole whose mass astronomers have yet to measure. In this case, scientists believe the rear-end collision accelerated and heated particles which illuminated the colliding material for Hubble to see.
The relativistic jet erupting from the accretion disk of the supermassive black hole thought to reside at the core of galaxy NGC 3862 is one of the most studied and therefore best understood. It’s also one of the few active galaxies with jets observed in visible light. It appears to stream out of the accretion disk at speeds several times the speed of light, but this is just a visual illusion referred to as superluminal motion created by the combination of insanely fast velocities and our line of sight being almost on point. It forms a narrow beam hundreds of light-years in length that eventually begins to spread out like a cone, before forming clumps at around 1,000 light-years. Clumps scientists study looking for clues pointing to facts they can use to learn more about these plasma jets and the cosmos.
Astronomers have observed knots of material being ejected from dense stellar objects previously during the human journey to the beginning of space and time. This is one of the few times they have detected knots with an optical telescope thousands of light-years from a supermassive black hole. It’s the certainly the first time we have detected a rear-end collision between separately ejected knots in a relativistic jet.
“Something like this has never been seen before in an extragalactic jet,” said Eileen Meyer of NASA’s Space Telescope Science Institute (STScI). “As the knots continue merging they will brighten further in the coming decades. This will allow us a very rare opportunity to see how the energy of the collision is dissipated into radiation.”
What would cause successive jets of material to achieve varying speeds? One theory involves the idea of material falling onto the supermassive black hole being superheated and ejected along its spin axis. Ejected material is constrained by the powerful magnetic fields surrounding the monster black hole into a narrow beam. If the flow of falling material isn’t perfectly smooth, knots are ejected in a string, rather than a continuous beam or steady hose.
It’s possible knots ejected later travel through a less dense interstellar medium, which would result in varying speeds. In this scenario, a knot launched after another knot would eventually catch up and rear-end it.
Beyond learning knots of material ejected in plasma jets erupting from the accretion disk of a supermassive black hole sometimes rear-end each other, astronomers are interested in this second case of superluminal motion observed in jets hundreds, thousands of light-years from the source supermassive black hole. This indicates the jets are still moving at nearly the speed of light at distances rivaling the scale of the host galaxy and still contain tremendous energy. Understanding this could help astronomers determine more about the evolution of galaxies as the cosmos ages, including our own Milky Way.
Astronomers are also trying to figure out why galaxy NGC 3862 is one of the few they have detected jets in optical wavelengths? They haven’t been able to come up with any good theories on why some jets are detected in visible light and others aren’t.
Work goes on
Work at the institute continues. Meyer is currently working on additional videos using Hubble images of other relativistic jets in nearby galaxies to try to detect superluminal motion. This is only possible due to the longevity of the Hubble Space Telescope and ingenuity of engineers and scientists from NASA and the ESA. Hopefully, they could discover more clues to answer these questions and other mysteries gnawing at the corner of my mind.
Can blow star-forming gas 1000 light-years out of core region of host galaxies
Space news (astrophysics: evolution of galaxies; feedback mechanisms) – about 2.3 billion years ago in a galaxy far, far away and standing in a fierce, 2 million mile per hour (3 million kilometers per hour) outflow of star-forming gas –
Astrophysicists studying the evolution of galaxies using the Suzaku X-ray satellite and the European Space Agency’s Herschel Infrared Space Observatory have found evidence suggesting supermassive black holes significantly influence the evolution of their host galaxies. They found data pointing to winds near a monster black hole blowing star-forming gas over 1,000 light-years from the galaxy center. Enough material to form around 800 stars with the mass of our own Sol.
“This is the first study directly connecting a galaxy’s actively ‘feeding’ black hole to features found at much larger physical scales,” said lead researcher Francesco Tombesi, an astrophysicist at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, and the University of Maryland, College Park (UMCP). “We detect the wind arising from the luminous disk of gas very close to the black hole, and we show that it’s responsible for blowing star-forming gas out of the galaxy’s central regions.”
The artist’s view of galaxy IRAS F11119+3257 (F11119) above shows 3 million miles per hour winds produced near the supermassive black hole at its center heating and dispersing cold, dense molecular clouds that could form new stars. Astronomers believe these winds are part of a feedback mechanism that blows star-forming gas from galaxy centers, forever altering the structure and evolution of their host galaxy.
Astronomers have been studying the Monster of the Milky Way, the supermassive black hole with an estimated mass six million times that of Sol thought to reside at the center of our galaxy, for years. The monster black hole at the core of F11119 is thought to contain around 16 million times the mass of Sol. The accretion disk surrounding this supermassive black hole is measured at hundreds of times the diameter of our solar system. The 170 million miles per hour (270 million kilometers per hour) winds emanating from its accretion disk push the star-forming dust out of the central regions of the galaxy. Producing a steady flow of cold gas over a thousand light-years across traveling at around 2 million mph (3 million kph) and moving a volume of mass equal to around 800 Suns.
Astrophysicists have been searching for clues to a possible correlation between the masses of a galaxy’s central supermassive black hole and its galactic bulge. They have observed galaxies with more massive black holes generally, have bulges with proportionately larger stellar mass. The steady flow of material out of the central regions of galaxy F11119 and into the galactic bulge could help explain this correlation.
“These connections suggested the black hole was providing some form of feedback that modulated star formation in the wider galaxy, but it was difficult to see how,” said team member Sylvain Veilleux, an astronomy professor at UMCP. “With the discovery of powerful molecular outflows of cold gas in galaxies with active black holes, we began to uncover the connection.”
“The black hole is ingesting gas as fast as it can and is tremendously heating the accretion disk, allowing it to produce about 80 percent of the energy this galaxy emits,” said co-author MarcioMeléndez, a research associate at UMCP. “But the disk is so luminous some of the gas accelerates away from it, creating the X-ray wind we observe.”
When the supermassive black hole’s most active, it clears cold gas and dust from the center of the galaxy and shuts down star formation in this region. It also allows shorter-wavelength light to escape from the accretion disk of the black hole astronomers can study to learn more. We’ll keep you updated on any additional discoveries.
What’s the conclusion?
Astrophysicists conclude F11119 could be an early evolutionary phase of a quasar, a type of active galactic nuclei (AGN) with extreme emissions across a broad spectrum. Computer simulations show the supermassive black hole should eventually consume the gas and dust in its accretion disk and then its activity should lessen. Leaving a less active galaxy with little gas and a comparatively low level of star formation.
Astrophysicists and scientists look forward to detecting and studying feedback mechanisms connected with the growth and evolution of supermassive black holes using the enhanced ability of ASTRO-H. A joint space partnership between Japan’s Aerospace Exploration Agency (ISAS/JAXA) and NASA’s Goddard Space Flight Center, Suzaku’s successors expected to lift the veil surrounding this mystery even more and lay the foundation for one day understanding a little more about the universe and its mysteries.
Watch an animation made by NASA’s Goddard Space Flight Center showing how black hole feedback works in quasars here.
Survey of 170,000 supermassive black holes says “we need to re-examine present theory”
Space news (astrophysics: Unified Theory of Active, Supermassive Black Holes; rethinking the present theory) – supermassive black holes scattered around the cosmos –
One common theme in astronomy and science is “the more we test a current theory, the more we need to re-examine our ideas and thoughts”. Theory one day is tomorrows’ old idea. Astronomers looking at archived WISE data found this out the other day. After examining data collected by NASA’s Wide-field Infrared Survey Explorer, they determined varying appearances of similar supermassive black holes could be a more complicated than present theory indicates. That it could be time to rethink the Unified Theory of Active, Supermassive Black holes, now that we have a little data to base our ideas and theories on.
The Unified Theory of Active, Supermassive Black Holes was first proposed in the late 1970s to explain the different appearance of active supermassive black holes with similar natures. Why some active monsters appear to be shrouded by dust and gas, while others are more exposed and easier to view.
“The main purpose of unification was to put a zoo of different kinds of active nuclei under a single umbrella,” said Emilio Donoso of the Instituto de CienciasAstronómicas, de la Tierra y del Espacio in Argentina. “Now, that has become increasingly complex to do as we dig deeper into the WISE data.”
This theory answered this query by suggesting all supermassive black holes are encased in a dusty, doughnut-shaped structure called a torus. That the appearance of the supermassive black hole and torus is dependent on the orientation of the system in space in relation to Earth. For instance, if the torus is viewed edge-on in relation to Earth, the supermassive black hole is hidden from view. However, if the torus is viewed from above or below, the monster within is visible.
“The unified theory was proposed to explain the complexity of what astronomers were seeing,” said Daniel Stern of NASA’s Jet Propulsion Laboratory (JPL) in Pasadena, California. “It seems that simple model may have been too simple. As Einstein said, models should be made ‘as simple as possible, but not simpler.”
Time to rethink the theory
WISE data collected before it was put on standby in 2011 indicates The Unified Theory of Active, Supermassive Black Holes isn’t the whole story and needs to be re-examined. That something other than the shape of the structures surrounding supermassive black holes determines whether a monster is viewable from Earth. Astronomers working on theories concerning supermassive black holes are looking at the data and thinking of new ways for supermassive black holes surrounded by structures of dust and gas to become visible from Earth. They hope their work and findings inspire further study and investment in uncovering more clues to the mysteries surrounding supermassive black holes and understanding of these enigmatic, yet fascinating objects.
“Our finding revealed a new feature about active black holes we never knew before, yet the details remain a mystery,” said Lin Yan of NASA’s Infrared Processing and Analysis Center (IPAC), based at the California Institute of Technology in Pasadena. “We hope our work will inspire future studies to better understand these fascinating objects.”
Proving scientific theory prescribes usage of the old adage, “the more things change, the more they stay the same” when developing theories.
You can learn more about the United Theory of Active, Supermassive Black holes here.
Hypernova SN 2006gy was over a hundred times brighter than a typical supernova
Space news (astrophysics: hypernovae; one of the brightest ever, SN 2006gy) – 240 million light-years toward the constellation Perseus in galaxy NGC 1260 –
It all started in September of 2006 when a fourth-year University of Texas graduate student astronomer working for the Palomar Transient Factory’s (PTF) luminous supernova program Robert Quimby discovered the brightest celestial event up to this date. An exploding star over 100 times brighter than a normal supernova and shining brighter than the core of its host galaxy NGC 1260.
“This was a truly monstrous explosion, a hundred times more energetic than a typical supernova,” said Nathan Smith of the University of California at Berkeley, who led a team of astronomers from California and the University of Texas at Austin. “That means the star that exploded might have been as massive as a star can get, about 150 times that of our sun. We’ve never seen that before.”
Teams of astronomers working with the Katzman Automatic Imaging Telescope at the Lick Observatory on Mt. Hamilton in California and M.W. Keck Observatory near the summit of Mauna Kea on the island of Hawaii immediately began observing the event designated supernova SN 2006gy. Analysis of data showed it occurred over 240 million light-years away in galaxy NGC 1260 and took 70 days to reach maximum brightness. Staying brighter than any previously recorded event for over three months, SN 2006gy was still as bright as a normal supernova eight months later.
“Of all exploding stars ever observed, this was the king,” said Alex Filippenko, leader of the ground-based observations at the Lick Observatory at Mt. Hamilton, Calif., and the Keck Observatory in Mauna Kea, Hawaii. “We were astonished to see how bright it got, and how long it lasted.”
Astronomers were reasonably sure at this point the progenitor of supernova SN 2006gy was one of the largest, most massive types of stars ever to exist. But they needed to rule out the most likely alternative explanation for the event. The possibility a white dwarf star with a mass slightly higher than Sol went supernova in a dense, hydrogen-rich environment.
Another team of astronomers using the Chandra X-ray Observatory went to work at this point to rule this possibility out of their equations. If this was the case, they knew X-ray emission from the event should be at least 1,000 times more luminous than the readings they were getting.
“This provides strong evidence that SN 2006gy was, in fact, the death of an extremely massive star,” said Dave Pooley of the University of California at Berkeley, who led the Chandra observations.
The progenitor star for SN 2006gy is thought to have ejected a large volume of mass before the hypernova event occurred. This is similar to events observed by astronomers in the case of Eta Carinae, a nearby supermassive star they’re watching closely for signs of an impending supernova. Only 7,500 light-years toward the constellation Carina, compared to 240 million for galaxy NGC 1260, this star going supernova would be the celestial event of the century on Earth. It would be bright enough to see in the daylight sky.
“We don’t know for sure if Eta Carinae will explode soon, but we had better keep a close eye on it just in case,” said Mario Livio of the Space Telescope Science Institute in Baltimore, who was not involved in the research. “Eta Carinae’s explosion could be the best star-show in the history of modern civilization.”
So many questions
Astronomers think in the case of hypernova SN 2006gy things might have taken a slightly different pathway than previously recorded supernovae. Some scientists think the massive star that exploded could be much more like the supermassive stars that existed during the early moments of the cosmos. Supermassive stars that exploded in supernovae and spread the elements of creation across the cosmos, rather than collapsing to a black hole as theorized.
“In terms of the effect on the early universe, there’s a huge difference between these two possibilities,” said Smith. “One [sprinkles] the galaxy with large quantities of newly made elements and the other locks them up forever in a black hole.”
Why would these supermassive stars be different than other huge stars observed in the Milky Way? The human search for answers to these and other mysterious questions before us continues as we journey backward to the beginning of space and time.
We’ll update you with any additional data astronomers come across as the journey continues. Until next time, keep dreaming of the possibilities.
Editor and Chief
The Human Journey to the beginning of space and time.
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.
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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.