Unlike anything seen during the human journey to the beginning of space and time
October 15, 2015 – 32 light-years toward the southern constellation Microscopium
Astrophysicists viewing four years of data provided by NASA’s Hubble Space Telescope and the European Southern Observatory’s (ESO) Very Large Telescope in Chile have discovered something unlike anything is ever seen before. Fast-moving, wave-like structures hidden within the dusty disk orbiting young star AU Microscopii (AU Mic), where they have been looking for clues to the processes leading to the formation of young planets.
Moving across the 40 billion-mile wide disk orbiting young star AU Microscopii at 22,000 mph, the string of ripples in the images above are moving at different speeds. Astronomers believe the features further away from AU Microscopii are moving faster than the ones closer to the star. At least, three are moving at a velocity which will result in them leaving the gravitational influence of the young star.
“The images from SPHERE show a set of unexplained features in the disk, which have an arc-like, or wave-like structure unlike anything that has ever been observed before,” said Anthony Boccaletti of the Paris Observatory, the paper’s lead author.
“We ended up with enough information to track the movement of these strange features over a four-year period,” explained team member Christian Thalmann of the Swiss Federal Institute of Technology in Zurich, Switzerland. “By doing this, we found that the arches are racing away from the star at speeds of up to 10 kilometers per second (22,000 miles per hour)! “ Co-investigator Carol Grady of Eureka Scientific in Oakland, California, added, “Because nothing like this has been observed or predicted in theory we can only hypothesize when it comes to what we are seeing and how it came about.”
Velocities reaching 22,000 miles per hour rule out the possibility of proto-planets within the dusty disk causing the gravitational disturbance detected. Calculations also indicate this phenomenon isn’t related to a collision between two massive bodies or unknown gravitational instabilities in the system of AU Mic. This team of astronomers is currently testing other theories in order to rule out other possibilities, but at this time, they’re just as mystified as the rest of us.
“One explanation for the strange structure links them to the star’s flares. AU Mic is a star with high flaring activity — it often lets off huge and sudden bursts of energy from on or near its surface,” said co-author Glenn Schneider of Steward Observatory in Phoenix, Arizona. “One of these flares could perhaps have triggered something on one of the planets — if there are planets — like a violent stripping of material, which could now be propagating through the disk, propelled by the flare’s force.”
Astronomers now plan on additional observations of the AU Mic system using the Hubble Space Telescope, the European Southern Observatory’s (ESO) Very Large Telescope and other ground and space-based telescopes. To look for answers to the mystery surrounding fast-moving, wave-like structures hidden within the dusty disk surrounding young star AU Microscopii.
You can read more about this in the Oct. 8 edition of the British science journal Nature.
You can discover more about AU Microscopii and the Hubble Space Telescope here.
Journey across the cosmos with the European Southern Observatory’s Very Large Telescope here.
You can learn about NASA’s mandate to travel to the stars here.
It took five decades to develop and ultimately launch the Hubble Space Telescope
Future space telescopes (Oct. 15, 2014) –
Traveling and exploring space is an adventure unlike anything experienced by travelers during thousands of years of life on Earth. A space journey requires careful planning, patience, and determination far beyond any adventure ever undertaken by people traveling over land or water. Exploring space for possible new worlds orbiting distant stars takes a space telescope requiring decades to develop and ultimately launch into space.
For example, the space telescope most people associate with hunting for new worlds, the Hubble Space Telescope, took five decades to design, engineer and finally launch into space. In the same fashion, the James Webb Space Telescope is expected to make the leap into space in 2018, almost 24 years after work first started on the idea. In fact, NASA engineers and scientists believe it will take so long to actually build a true successor to the Hubble Space Telescope, they have already started work on a replacement.
Dubbed the Advanced Telescope Large-Aperture Space Telescope (ATLAST), the successor to the first planet hunter incorporates improved technology first pioneered by the Hubble and James Webb Space Telescopes. Studying the ultraviolet, visible and near-infrared universe, ATLAST is designed to be a long-term space observatory for the next phase of the human journey to the beginning of space and time. Engineers and scientists are currently taking a look at the costs and scientific and technical requirements of constructing a replacement planet hunter sometime within the next twenty or thirty years.
“Conceptually, ATLAST would leverage the technological advances pioneered by the Webb telescope, such as deployable, large segmented mirror arrays,” said Mark Clampin, ATLAST study scientist and Webb’s project scientist.
“We will be leveraging a lot of heritage from the Webb telescope and then developing new technologies over the next few years for the primary mirror assembly, wavefront sensing and control, and ultra-stable structures to achieve this wavefront error stability,” Clampin said.
“One of the killer apps currently planned for ATLAST is the ability to detect signatures of life in the atmospheres of Earth-like planets in the solar neighborhood,” Clampin said.“While other observatories will image larger exoplanets, they would not have ATLAST’s advanced ability to identify chemicals that may indicate the presence of life in these far-flung, Earth-size worlds.”
ATLAST will reside in the same Sun-Earth L2 orbit the James Webb Space Telescope will occupy once it’s launched around 2018. Carrying a state-of-the-art star shade designed to help reduce the light from an Earth-sized planet’s home star, ATLAST should detect worlds that could be a new cradle for the human race to begin life again.
ATLAST also has a large main mirror capable of studying star and galaxy birth in high definition. It would be able to provide detailed images of stars in galaxies over 10 million light-years away and regions of space where new stars are being created over 100 parsecs in size anywhere in the visible universe. This mirror would be quite a bit larger than the largest segmented mirror NASA has ever launched into space, the one on the Hubble Space Telescope.
NASA identified a need to begin development of a replacement for Hubble and James Webb Space Telescope in a recent document outlining its vision for astrophysics during the next three decades titled “Enduring Quests, Daring Visions“.
“While people expect Hubble and Webb to operate for many years, we are looking ahead to the telescope and instrument requirements needed to answer the questions posed in NASA’s 30-year vision,” said Harley Thronson, the Goddard senior scientist for Advanced Concepts in Astrophysics and ATLAST study scientist.
“ATLAST would achieve critically important science goals not possible with ground-based observatories or with any other planned space missions,” added Thronson. “Now is the time to plan for the future.”
“One of the pertinent attributes about ATLAST is that it’s being designed to be modular and serviceable, following the Hubble Space Telescope model,” observed Julie Crooke, one of the Goddard study leads. “Mission planners would design the observatory so that it could be serviced to upgrade instrumentation — a potential capability that depends on available budget and science requirements. Serviceability has been one of the great paradigms in mission architecture that separates the Hubble Space Telescope from all of the other space missions to date,” Crooke said.
Stars begin life as clouds of cold gas and dust that transform into blazing hot fireballs
Star dust, star dust, burning bright
Amid the glare of ancient light
Eternity stares back from the past
Reborn we’ll be one day at last
NASA astronomy: stellar astrophysics
Astronomy questions and answers – September 19, 2013 – Walk out to a dark viewing spot anywhere on the Earth on a clear night and look up at the night sky. Your eyes will take in ancient light from stars in the Milky Way that covers the whole sky above you. Deep within the stellar nurseries of the Milky Way new stars are being formed using processes NASA astronomers are currently studying in an attempt to understand how stars are born. Star forming processes responsible for the formation of the stars you see in the night sky. Processes they can see at work in the stellar nurseries of the Milky Way, like the Orion Nebula (M42) and Cygnus X.
Journey with me to stellar nurseries deep within the dark regions of the Milky Way, the dark patches you can see in the night sky above. The birthing grounds of young stars in the Milky Way, these dark patches in the night sky are in fact clouds of interstellar gas that appear dark because they block the starlight from distant stars. Astronomers believe deep within the birthing grounds of the Milky Way, new stars are being formed at the rate of about 2 or 3 new stars each year.
Star formation theories
Present theories on star formation put forth by NASA astronomers show star formation is a complicated process affected by nearby massive stars, other star forming regions, and even the spiral structure of the Milky Way. These theories only become more complicated when astronomers look at the formation of groups of stars.
In order to try to simulate star formation, some astronomers use sophisticated computer models, while others incorporate observations in different wavelengths and use them to create three-dimensional images of the sky. Working together these two different groups of astronomers are trying to determine exactly how stars are born.
NASA astronomers working on present theories of star formation think the Milky Way is filled with clouds of gas and dust they call the interstellar medium. They also think slight over densities within these clouds of gas and dust could trigger star formation, over densities that could be produced by the turbulent forces present in these clouds of gas and dust. Astronomers studying slight over densities within star forming clouds of gas and dust believe these slightly denser regions could eventually become main sequence stars within a few million years.
Some NASA astronomers believe the intense radiation from groups of hot, bright stars located close to one another could create the necessary turbulence in the interstellar medium to trigger star formation. Other astronomers believe nearby galaxies and even large clouds of gas and dust could cause turbulence in the interstellar medium which could also be part of the star forming process. Many astronomers also believe the resulting shock wave after a supernova could create spiral density waves capable of compressing material and initiating star formation.
Gravity at Work
Present theories on the formation of main sequence stars being proposed by NASA astronomers involves the force of gravity. Gravity pulls the gas and dust within the interstellar medium into denser regions, which results in a cloud increasing in size and contracting. The rotation velocity of the cloud increases as it contracts due to conservation of angular momentum, in the same way a figure skater’s spin speed increases as they bring their arms closer to their body.
At the same time the temperature in the core of the cloud increases as it shrinks due to the force of gravity. The charged particles within the cloud at this time can only move in specific directions in the magnetic field in the region. This results in the rotational velocity of the cloud slowing, but not stopping, otherwise astronomers think stars would never form in these dense clouds of gas and dust.
In the case of main sequence stars astronomers think regions of dense clouds of gas and dust would begin to contract to an area the size of our solar system tens of thousands of years after beginning to slow. At this time astronomers think the temperature at the centre of dense clouds of dust and gas would be in the region of 10,000 kelvins. They call the central region of such a cloud at this time a protostar.
Protostars at this time in their life cycle are often more luminous than the main sequence star they eventually become, because they have a greater surface from which to radiate energy. This brightness allows NASA astronomers to view protostars as they continue to gravitationally attract more gas and dust, shrink and heat up internally. The luminosity of a protostar begins to decrease as it’s outer surface shrinks under the force of gravity. Astronomers believe the cloud and protostar eventually spin faster and flatten out into a disk.
Astronomers using data collected by several different astronomical instruments recently presented far-infrared images of three Class 0 protostar systems in Perseus: L1448C, the triple system L1448N, and IRAS 03282+3035. Seven hundred and fifty light-years from Earth, all three of these protostars were seen powering bipolar molecular outflows, which astronomers think are in fact epic jets of water being thrust into interstellar space. Calculations by NASA astronomers indicates these jets of water are shooting out into interstellar space at speeds of around 120,000 miles per hour and at a rate equal to about 100 million times the volume of water flowing in the Amazon every second of the day.
Astronomers think these jets of water and material help to channel radiation and mass away from the protostar, which helps to clear the central region of debris and reveal the protostar. They also think it could be possible the galaxy was seeded with water through this process, which might change thoughts on the possibility of life in the galaxy. The remaining material is then accreted by the protostar, or forms part of a residual disk, which NASA astronomers think could form planets.
The core of a protostar will reach 1 million kelvin at sometime during the contraction and heating up of the cloud, at which time it will begin fusing deuterium to helium. Deuterium is the easiest nucleus to fuse, so it makes sense this would be the starting point. Once the core has contracted enough to reach a density where the core reaches 10 million degrees kelvins, hydrogen nuclei will begin fusing into helium. At this point star astronomers also think a protostar will reach an equilibrium point where the radiative energy from fusion balances gravitational pull of its mass. This new star is now a main sequence star, which has formed over millions of years.
Simulating the Birth of a Star
The process of star birth takes millions of years to complete, so how do astronomers determine the way outside factors affect the process by which new stars are born? Modern astronomers are presently using supercomputers to help simulate star formation models in the hope they can determine why the mass distribution of newly formed stars appears to be universal. They want to understand why this average mass of newly formed stars exists. They also want to know the process by which it occurs.
Present star formation models take into account the effects of thermodynamics, magnetic fields, radiative processes, and of course gravity. Star astronomers are also trying to determine other factors they need to include in models, like the way new stars affect their own star forming environments. This includes factors like young stars heating up the gas and dust surrounding them and moving gas and dust around through bipolar molecular flows.
The key question NASA astronomers want to answer at this point is whether or not present star formation models can reproduce the properties of exact parts of the star forming process. Astronomers will also want to determine the most massive star that can be formed depending on the size of a cloud of dust and gas. They’ll try to find answers by looking at the chemical composition, magnetic fields, ionization, age and other factors of large clouds of star forming dust and gas in the night sky.
Peering into Stellar Nurseries
How do NASA astronomers look into the heart of stellar nurseries in the Milky Way? Astronomers use instruments designed to detect specific wavelengths of light radiation emitted during the formation of new stars. During the beginning stages of star birth a new star emits radio waves as it contracts astronomers look for as an indicator of new star formation. At this time the core of a contracting cloud of gas and dust is too cold to emit visible and infrared radiation.
Once the cloud forms a protostar it will begin to emit light radiation, which will be blocked by the material surrounding the new star. The light radiation emitted by a protostar is absorbed by the surrounding material, which radiates infrared radiation toward Earth NASA astronomers detect using space and ground-based telescopes specifically designed for the job.
Astronomers have used the Spitzer Space Telescope to view hundreds of protostars forming in large clouds of gas and dust in the stellar nurseries of the Milky Way. In the future they’ll use instruments and telescopes designed to detect millimetre waves in the microwave range in order to get a better view of the beginning stages of star birth. To date astronomers report detecting a compact source embedded in cold gas within stellar nurseries only detectable at these wavelengths.
NASA astronomers trying to piece together the puzzle of star formation in the Milky Way are also using reconstructed images of star-forming regions from past observations. Using 2-D images, positional data, and velocities for an entire cloud, they have been able to create 3-D models researchers can then analyze. 3-D models that show unforeseen structures hidden within stellar nurseries and even regions of star formation they weren’t expecting to see.
Click this link to watch a You Tube videos on how a star is born