Astronomy news (November 28, 2013) – The Hubble Space Telescope, along with the light magnifying ability of the effect called gravitational lensing, has provided the first views of the most distant galaxy seen during the human journey to the beginning of space and time. The astronomers of the Cluster Lensing and Supernova Survey with Hubble (CLASH) recently discovered three gravity-lensed images of a galaxy that existed over 13.7 billions years ago taken using Hubble’s new panchromatic imaging capabilities. Designated MACS 0647-JD, this ancient star city is currently the most distant galaxy located to date using the Hubble Space Telescope and gravitational lensing.
The CLASH program
The astronomers of CLASH used the Hubble Space Telescope to look at 25 distant galaxy clusters during the period from November 2010 to July 2013. They were looking for light which had been magnified due to the effect known as gravitational lensing as predicted by Einstein’s General Theory of Relativity. They wanted to detect additional Type Ia supernovae, map the distribution of dark matter in galaxy clusters, detect the most distant galaxies ever and study the internal structure and evolution of the galaxies in and behind these clusters.
The three gravity-lensed images taken by Hubble are of a small galaxy, now designated MACS 0647-JD, which could have been one of the first galaxies to exist in the universe. Astronomers’ analysis of the images suggests this small galaxy was less than 600 light-years across, which may indicate it was in the first stages of galaxy formation. In fact, this smaller galaxy may have been just one building block in the construction of a larger galaxy, and during the past 13.7 billions years could have been part of dozens, hundreds and even thousands of merging events with other galaxies.
Astronomers look at other possibilities
The astronomers of the Cluster Lensing and Supernova Survey with Hubble recently used the ability of NASA’s Spitzer Space Telescope to help rule out other possible identities of the three images they found. Next, astronomers will use the Spitzer Space Telescope, and other telescopes, to confirm the existence of the galaxy and try to get a better estimate of its age.
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
Green Lantern’s emerald ring beams across space and time at NASA’s Spitzer Space Telescope
Astronomy NASA News – Visitors from the stars have often been the main characters in myths, legends, comic book adventures and books and movies created by humans throughout the ages of mankind. Considering the diminutive knowledge astronomers have of space and time this choice provides the perfect context for adventure and the unknown. The Green Lantern is one of the most popular and beloved DC Comics heroes of all time and more recently a full length feature film starring Ryan Reynolds, Blake Lively and Peter Sarsgaard. The original Green Lantern Alan Scott was created by writer Bill Finger and commercial artist Martin Nodell for All American Comics #16 (July 1940) edition. Since this time the Green Lantern alias has been shared by several DC Comics superheroes and fictional characters that have all contributed to the popularity of this timeless character.
Emerald ring nebula born in the fire of massive O type stars
Astronomers on the leading edge of the human journey to the beginning of time and space recently glimpsed this emerald nebula using NASA’s Spitzer Space Telescope. Reminiscent of the emerald ring wielded by the Green Lantern, this emerald ring wasn’t forged by the Guardians of the Universe as the power rings of the Green Lantern Corps were in the original Green Lantern adventures. Astronomers viewing scenes like the one in the picture above believe emerald nebula like the one seen here are in fact born in the fire of the most massive stars viewed on the human journey to the beginning of the universe O type stars. This particular emerald nebula lies deep within clouds of hot gas and glowing dust in the constellation Scorpius and has been given the name RCW 120 by astronomers. The green ring we see is in fact glowing in infrared colours our eyes aren’t designed to view, but using the infrared detectors of the Spitzer Space Telescope astronomers can produce images like this one.
Green Lantern’s ring
The green ring viewed here was actually carved out by the intense ultraviolet radiation of a couple of giant stars near the centre of the nebula. The giant stars will be obscured by the light from the other stars nearby, when viewed by the infrared detectors of NASA’s Spitzer Space Telescope. Ring nebula like this one have actually been a common sight on the human journey to the beginning of space and time, so common that professional astronomers have asked amateur star gazers to take part in the search for ring nebula. Astronomy lovers interested in taking part in the search for ring nebula should contact the people in charge of The Milky Way Project, at http://www.milkywayproject.org/.
Take a “Journey to the Beginning of Space and Time” and view exoplanets that might be more like death-planets for humans
Surviving space is going to be hard
Astronomy News – Planets circling twin stars close in proximity could be a real tough place for life to begin, according to the conclusions of a study conducted using data from NASA’s Spitzer Space Telescope. Space scientists using NASA’s infrared observatory recently found what they believe to be clouds of possible dust around three mature, close-orbiting binary stars. Dust that scientists think is possibly the result of the planets orbiting these twin stars colliding, which could make living on these planets difficult for any lifeforms that might have arisen on these planets.
Planetary collisions are possible real-life science fiction in action, as the reasons for the dust clouds are certainly a matter of conjecture and something that any science fiction writer is going to be able to spin a tale of annihilation around. Lifeforms evolving under the environmental conditions that possibly exist on planets orbiting binary stars of the particular class studied would certainly be something beyond the imagination of any human writer. It’s unlikely that anything we humans create using our imaginations could ever match the possibilities that exist in space and time. The finite imaginations of humans are limited by our senses, experiences and the limits of what we refer to as our human perception or intelligence to some.
Lifeforms evolving on these planets would have to survive possible planetary collisions at regular intervals if space scientists conclusions are correct? If they have the ability to sense the world beyond their normal lives? Lifeforms existing on these planets could be non-sentient and unable to perceive the annihilation above them. They could be looking up at annihilation coming toward them in the form of another planet, asteroid, or other celestial body orbiting the binary star systems in question. They may have been destroyed in a recent collision between planets and are space dust, once again. The view would be a spectacular one, though, with two huge suns that would exceed anything we experienced viewing the double stars systems in the Star Wars Saga.
Humans will evolve on any new planet they inhabit
Life evolving on planets circling binary stars like the ones in question would have a limited time to evolve into a space traveling sentient race as well. The suns in the binary star system they have evolved on are slowly circling closer and closer, according to astronomers, which could possibly make surviving and evolving on these planets a lot more difficult. Lifeforms surviving and thriving on these planets would likely be a survivor beyond human imagination, so we should probably thank our lucky stars that they aren’t likely to be stopping by for a visit, anytime soon.