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.
They believe could be evidence for young, massive planets orbiting new stars
Space news (November 23, 2015) –
Astronomers working with ground-based telescopes are proposing massive swirl designs viewed encircling newborn stars could betray the presence of infant planets. Opening the door to a new method of possibly detecting exoplanets orbiting stars and offering a look at the processes forming planets in the cosmos.
The human journey to the beginning of space and time has detected over 1,000 exoplanets around distant stars during the last few years. Detecting infant planets being formed around a nearby, young star enveloped by acircumstellar disk of gas and dust is a different story. Presently, astronomers can’t detect nascent planets embedded inside a vast, pancaked-shaped circumstellar disk.
Those infant planets being formed around young stars could be detected based on the changes they make in the circumstellar disk is a new concept. A new concept based on computer modeling of the birth and evolution of massive disks of dust and gas surrounding young stars. Computer modeling conducted by two NASA Hubble Fellows, Zhaohuan Zhu of Princeton University and Ruobing Dong of Lawrence Berkeley National Laboratory.
“It’s difficult to see suspected planets inside a bright disk surrounding a young star. Based on this study, we are convinced that planets can gravitationally excite structures in the disk. So if you can identify features in a disk and convince yourself those features are created by an underlying planet that you cannot see, this would be a smoking gun of forming planets,” Dong said.
This new planet-finding technique could be significant in the desire to find young, newly-formed planets and understanding the processes the cosmos uses to make them. This approach could be the piece of the puzzle astronomers have been looking for to help unwrap the mystery surrounding the formation of planets. A mystery planetary scientists have been studying in depth for years andone they would love to understand more about.
Computer models show gaps and rings in circumstellar disks could be unseen planets embedded in massive, light-absorbing clouds of gas and dust. Gaps and rings possibly swept clean by the gravity field of a planet or planets, which makes it difficult to determine their number, individual mass, or location.
Astronomers using ground-based telescopes have imaged two massive spiral arms surrounding two newly-formed stars called SAO 205462 and MWC 758. They have also detected similar looking spiral features in nearby stars they’re currently studying to try to gain a better understanding of exactly what’s going on beneath the veil of gas and dust surrounding these distant celestial bodies.
“How they are created has been a big mystery until now. Scientists had a hard time explaining these features,” Dong said. “If the disks were very massive, they would have enough self-gravity to become unstable and set up wave-like patterns. But the disks around SAO 206462 and MWC 758 are probably just a few percent of the central star’s mass and therefore are not gravitationally unstable.“
Additional computer models suggest the dynamics of disks surrounding newly-formed suns are altered by the radiation of a star as it moves through a disk with embedded planets. Computer modeling closely resembling the spiral structures imaged by astronomers points tomutual gravitational fields of newly-formed stars and surrounding disks interacting. This interaction creates regions surrounding newly-formed stars where the density of gas and dust increases until they form spiral waves. Spiral waves that are spread out over these regions by the varying rates of rotation of the disk around the newly-formed star.
“Simulations also suggest that these spiral arms have rich information about the unseen planet, revealing not only its position but also its mass,” Zhu said. “The simulations show that if there were no planet present, the disk would look smooth. To make the grand-scale spiral arms seen in the SAO 206462 and MWC 758 systems, the unseen planet would have to be bulky, at least 10 times the mass of Jupiter, the largest planet in our solar system.“
“There are many theories about how planets form but very little work based on direct observational evidence confirming these theories,” Dong said. “If you see signs of a planet in a disk right now, it tells you when, where, and how planets form.”
Astronomers and planetary scientists will now continue their studies of newly-formed star systems and the processes the cosmos uses to create them. They’re planning on using current ground and space-based telescopes to study young star systems. In the years ahead they also usethe James Webb Space Telescope to lift the veil of mystery surrounding the birth and evolution of stars in the universe.
Erupting X-ray flares every day, a ten-fold increase in bright flares from previous observations of Sagittarius A
Space news (October 01, 2015) – 26,000 light-years from Earth, near the center of the Milky Way
Astrophysicists combining the telescopic talents of NASA’s Chandra X-ray Observatory and Swift spacecraft, with the European Space Agency’s X-ray Space Observatory XMM-Newton, recently detected an increase in X-ray flares erupting from the supermassive black hole (Sagittarius A) at the center of the Milky Way.
By analyzing data collected during extensive periods of monitoring by all three spacecraft, space scientists determined the Monster of the Milky Way – the supermassive black hole at the center with more than 4 million times the mass of Sol– has been more active during the past 15 years than first thought.
Erupting a bright X-ray flare every ten days, the Monster of the Milky Way has been eating hot gas falling into its gravity pool. Even more interesting, Sagittarius A during the past year has been erupting ten times as much, producing a bright X-ray flare every day. A discovery that has astrophysicists going over the data looking for a reason for the sudden increase.
“For several years, we’ve been tracking the X-ray emission from Sgr A*. This includes also the close passage of this dusty object” said Gabriele Ponti of the Max Planck Institute for Extraterrestrial Physics in Germany. “A year or so ago, we thought it had absolutely no effect on Sgr A*, but our new data raise the possibility that that might not be the case.”
The mystery started late in 2013, as G2 passed close to the supermassive black hole. At this time, there wasn’t any apparent change in G2 as it approached Sagittarius A, other than being slightly stretched by the gravity pool of the black hole.
Originally astronomers thought G2 was a stretched cloud of gas and dust, but this finding has led scientists to the possibility it could be a dense body embedded in a dusty cocoon. Currently, there’s no consensus among astronomers on the identity of this mysterious object. But the recent ten-fold increase in X-ray flares as G2 passed near the supermassive black hole suggests there could be a connection of some kind.
“There isn’t universal agreement on what G2 is,” said Mark Morris of the University of California at Los Angeles. “However, the fact that Sgr A* became more active not long after G2 passed by suggests that the matter coming off of G2 might have caused an increase in the black hole’s feeding rate.”
At this point, astronomers don’t know if the increase in X-ray flares from the supermassive black hole is common or unusual in nature. These emissions could be part of the normal life cycle of supermassive black holes and totally unrelated to the passage of G2. The ten-fold increase in X-ray flares could also be due to changing solar winds from nearby massive stars feeding gas and dust into the black hole.
Scientists will keep observing Sagittarius A over the next little while to see what pops up next in this mystery. Hopefully, they can shed some light on the reason the Monster of the Milky Way, suddenly started emitting X-ray flares once a day.
“It’s too soon to say for sure, but we will be keeping X-ray eyes on Sgr A* in the coming months,” said co-author Barbara De Marco, also of Max Planck. “Hopefully, new observations will tell us whether G2 is responsible for the changed behavior or if the new flaring is just part of how the black hole behaves.”
Twin iridescent jets of gas stream outward from a binary planetary nebula at over 1 million kilometers (621,400 miles) an hour.
Space news (September 24, 2015) –
First recorded flying across the constellation Ophiuchus – about 2,100 light-years from Earth – by Rudolph Minkowski in 1947, the Twin Jet Nebula (PN M2-9), or Wings of a Butterfly Nebula, is a remarkably complex and stunningly beautiful 1,200-year-old bipolar planetary nebula.
A bipolar nebulacomposed of an average star between 1 to 1.4 solar masses nearing the end of its life cycle and a smaller white dwarf between 0.6 to 1.0 solar masses that orbit a common center of mass. The Twin Jet Nebula gets its name from the shape of its two lobes, which look like butterfly wings to many viewers.
Astrophysicists think the shape of the wings (lobes) is mainly due to the unusual motion of the larger star and white dwarf around their common center of mass. Orbiting each other in around 100 years, the smaller white dwarf is thought to have stripped gas away from its larger companion star, which then formed an expanding ring of material around the starsfar too small to be seen by Hubble.
This disk of material was then stretched into the shape of two lobes resembling two butterfly wings, rather than a uniform sphere, due to the unusual motion of the two stars around their center of mass. The faint patches of blue within the wings, starting near the binary star system and extending outward horizontally, are twin jets of gas streaming outward at over 1 million kilometers an hour.These jets slowly change their orientation, precessing across the lobes (wings) as the two stars orbit each other.
Astrophysicists are now taking a closer look at the Twin Jet Nebula, and other bipolar nebulae, to try to determine if such systems always contain two stars orbiting a common center of mass. Currently, astronomers are discussing this possibility, and other scenarios possibly leading to the birth and growth of similar celestial objects and other phenomena.
Two astronomers working with NASA’s Hubble Space Telescope and the ESO’s New Technology Telescope also recently conducted a study of 130 planetary nebulae. Dr. Brian Rees and Dr. Albert Zijlstra of the University of Manchester in the United Kingdom found the long axis of many bipolar planetary nebulae studied all line up along the plane of the Milky Way. This alignment could have something to do with the magnetic field of the bulge at the center of our galaxy they think. You can read the abstract here.
Revealing protostars and giant clouds of gas and dust where new stars were born
Space news (August 18, 2015) – 7,000 light-years away toward constellation Serpens (The Serpent); the iconic Pillars of Creation
Astronomers working with the Multi Unit Spectroscopic Explorer (MUSE) on the European Southern Observatory’s (ESO) Very Large Telescope (VLT) have released the first 3D image of the Pillars of Creation in the Eagle Nebula (M16or Messier 16).
The Pillars of Creation are a stellar feature that is more common than people first assume. Similar structures and shapes have been and are quite frequently seen during the human journey to the beginning of space and time. The columns of the Pillars of Creation were formed when intense radiation and stellar winds from huge, newly formed blue-white O and B suns blew away less dense material in the region of space surrounding them.
A study has shown the very top of the left pillar in the image is pointing toward us and sitting on top of another pillar behind nearby stellar cluster NGC 6611. This top portion of the left pillar is bearing the majority of withering radiation from nearby stars and this is why it looks brighter to our eyes compared to the other pillars.
“I’m impressed by how transitory these structures are. They are actively being ablated away before our very eyes. The ghostly bluish haze around the dense edges of the pillars is material getting heated up and evaporating away into space. We have caught these pillars at a very unique and short-lived moment in their evolution,” explained Paul Scowen of Arizona State University in Tempe. He and astronomer Jeff Hester, formerly of Arizona State University, led the original Hubble observations of the Eagle Nebula.
Scowen said. “The gas is not being passively heated up and gently wafting away into space. The gaseous pillars are actually getting ionized, a process by which electrons are stripped off of atoms, and heated up by radiation from the massive stars. And then they are being eroded by the stars’ strong winds and a barrage of charged particles, which are literally sandblasting away the tops of these pillars.”
The denser material left behind acted as a shield against the harsh, withering glare of nearby brilliant young stars, and formed the shape of the region.The dark “tails” or “elephant trunks” viewed as the dark body of the pillars point away from the intense radiation and stellar winds of nearby brilliant stars.
Now, astronomers plan on studying how newborn O and B stars in NGC 6611 influence the growth of further generations of stars. Previous studies have detected protostars forming within the clouds of NGC 6611. The latest study also provided evidence for protostars forming in the middle and left clouds of the Pillars of Creation and there are also probably other protostars and young stars hidden from view within the region.
Astronomers want to study star-forming regions like the Pillars of Creation in order to better understand the conditions in which stars like our own Sun formed. Current evidence points to the early solar system being bombarded with radioactive shrapnel from a nearby supernova. This indicates we formed in a star-forming region with young stars massive enough to produce powerful ionizing radiation like we see in the Eagle Nebula.
“That’s the only way the nebula from which the sun was born could have been exposed to a supernova that quickly, in the short period of time that represents, because supernovae only come from massive stars, and those stars only live a few tens of millions of years,” Scowen explained. “What that means is when you look at the environment of the Eagle Nebula or other star-forming regions, you’re looking at exactly the kind of nascent environment that our sun formed in.”