Launching an accelerating fragment of the thin disk at 7 percent of the speed of light
Space news (July 25, 2015) – 7,500 light-years away in the constellation Centaurus
The majority of lights in the night sky above are double star systems composed of two suns orbiting each other. NASA space scientists using the Chandra X-ray Observatory observed the unusual double star system PSR B1259-63/LS 2883 (B1259 is the short version) three times between December 2011 and February 2014 looking for clues to its nature.
“These two objects are in an unusual cosmic arrangement and have given us a chance to witness something special,” said George Pavlov of Penn State University in State College, Pennsylvania, lead author of a paper describing these results. “As the pulsar moved through the disk, it appears that it punched a clump of material out and flung it away into space.”
Composed of a pulsar and companion star 30 times the mass of the Sun, B1259 is in a weird looking cosmic arrangement that has been kicking up a little dust lately. Recent data indicates the high-energy particle winds created by the combination of rapid rotation and intense magnetic field of the pulsar appears to have punched a hole in the disk of gas surrounding the companion star. A hole composed of gas that has been ejected from the disk at 4 million miles per hour and accelerated from 7 percent of the speed of light to 15 percent between the second and third observation periods.
“After this clump of stellar material was knocked out, the pulsar’s wind appears to have accelerated it, almost as if it had a rocket attached,” said co-author Oleg Kargaltsev of George Washington University (GWU) in Washington, DC.
The pulsar is an ultra-dense neutron star orbiting its companion star in a highly elliptical orbit that makes its closest approach every 41 months. The companion star is rotating at a speed resulting in a disk of material spinning off, creating the thin disk of gas surrounding the massive sun. The pulsar is expected to pass through the disk of material as it makes its next approach to B1259. NASA scientists expect to view the event and collect data on the unusual nature of this double star system.
41 months is enough time for NASA scientists to plan their next move and get other telescopes and spacecraft in place to view the event. NASA scientists will collect data on the effects of the stellar winds of the pulsar on the gas disk surrounding the companion star as it passes through. There could be another ejection of gas material as it passes close to B1259, next time, which is an opportunity to learn more about double star systems and the cosmos.
“This just shows how powerful the wind blasting off a pulsar can be,” said co-author Jeremy Hare, also of GWU. “The pulsar’s wind is so strong that it could ultimately eviscerate the entire disk around its companion star over time.”
NASA space scientists will next view double star system B1259, later in the year, and sometime in 2016. The next passing of the pulsar through the disk of gas surrounding its companion star could be even more spectacular and unusual in nature.
You can learn more about the Chandra X-ray Observatory here.
Space scientists have debated the nature and origin of high energy ultra-luminous x-ray sources for years
Space news (Oct. 28, 2014) –
Space scientists have been looking at celestial objects called ultraluminous x-ray sources (ULXs) for years in search of answers to the mystery surrounding their nature and origin. Celestial bodies radiating enormous amounts of high-energy x-rays, astronomers have been studying three nearby ULXs changing thoughts and present theory on these energetic characters.
Space scientists using the Chandra X-ray Observatory, Hubble Space Telescope, Swift Gamma-ray Burst Explorer and XMM-Newton Space Observatory have been studying two ULXs discovered in Andromeda galaxy (M31). The first is called CXOM31 and was discovered in 2009 using the Chandra X-ray Space Observatory. The second, XMMU, was discovered on Jan. 15, 2014 by the European Space Agency’s XMM-Newton spacecraft.
Space scientists believe both ULXs they observe in Andromeda are binary star systems with a black hole rapidly accreting (consuming) material from its neighbor at a rate near the theoretical Eddington limit (the maximum accretion rate of a black hole).
“There are four black hole binaries within our own galaxy that have been observed accreting at these extreme rates,” said Matthew Middleton, an astronomer at the Anton Pannekoek Astronomical Institute in Amsterdam. “Gas and dust in our own galaxy interfere with our ability to probe how matter flows into ULXs, so our best glimpse of these processes comes from sources located out of the plane of our galaxy, such as those in M31.”
“As gas spirals toward a black hole, it becomes compressed and heated, eventually reaching temperatures where it emits X-rays. As the rate of matter ingested by the black hole increases, so does the X-ray brightness of the gas. At some point, the X-ray emission becomes so intense that it pushes back on the inflowing gas, theoretically capping any further increase in the black hole’s accretion rate. Astronomers refer to this as the Eddington limit, after Sir Arthur Eddington, the British astrophysicist who first recognized a similar cutoff to the maximum luminosity of a star.”
“Black-hole binaries in our galaxy that show accretion at the Eddington limit also exhibit powerful radio-emitting jets that move near the speed of light,” Middleton said. “Although astronomers know little about the physical nature of these jets, detecting them at all would confirm that the ULX is accreting at the limit and identify it as a stellar mass black hole.”
Space scientists operating NASA’s Nuclear Array (NuSTAR) have also found the brightest ULX on record near the center of galaxy Messier 82 (M82) 12 million light-years away. Called M82 X-2, they believe this particular object is actually a dead pulsating star called a pulsar, rather than a binary star system with a black hole accreting material from its neighbor.
“Astronomers have found a pulsating, dead star beaming with the energy of about 10 million suns. This is the brightest pulsar – a dense stellar remnant left over from a supernova explosion – ever recorded. The discovery was made with NASA’s Nuclear Spectroscopic Telescope Array, or NuSTAR.”
“You might think of this pulsar as the ‘Mighty Mouse’ of stellar remnants,” said Fiona Harrison, the NuSTAR principal investigator at the California Institute of Technology in Pasadena, California. “It has all the power of a black hole, but with much less mass.”
This ULX being something other than a binary star system with an accreting black hole is surprising to astronomers. They’ll have to rethink present theories on the nature and origin of these mysterious celestial objects.
“The pulsar appears to be eating the equivalent of a black hole diet,” said Harrison. “This result will help us understand how black holes gorge and grow so quickly, which is an important event in the formation of galaxies and structures in the universe.”
“ULXs are generally thought to be black holes feeding off companion stars — a process called accretion. They also are suspected to be the long-sought-after “medium-sized” black holes – missing links between smaller, stellar-size black holes and the gargantuan ones that dominate the hearts of most galaxies. But research into the true nature of ULXs continues toward more definitive answers.”
“We took it for granted that the powerful ULXs must be massive black holes,” said lead study author Matteo Bachetti, of the University of Toulouse in France. “When we first saw the pulsations in the data, we thought they must be from another source.”
“Having a diverse array of telescopes in space means that they can help each other out,” said Paul Hertz, director of NASA’s astrophysics division in Washington. “When one telescope makes a discovery, others with complementary capabilities can be called in to investigate it at different wavelengths.”
Space scientists will now use NASA’s complete array of astronomical equipment and spacecraft to look at how this dead star is able to radiate x-rays so intensely. Plans are for NuSTAR, the Swift Gamma-ray Burst Explorer, and Chandra X-ray Space Observatory to have a look at the weird behavior of M82 X-2.
They’ll also start looking at other ULXs to see if they can find anymore that are pulsars, rather than a binary star system with an accreting black hole. This research could open a window of discovery on the true nature and origin of these energetic and enigmatic celestial objects.
April signal from Sagittarius the Archer reveals pulsar (Photo courtesy of NASA)
Friday, December 30, 2011 – “Astronomy delights the soul because of the mystery“
Astronomers recently detected a signal emanating from the constellation Sagittarius the Archer which after study turned out to be a type of x-ray pulsar often called an accretion-powered pulsar. Accretion-powered pulsars have to this point in the human journey to the beginning of time and space always appeared as part of a binary star system with a normal type star. In this scenario the powerful gravity field of the neutron star is able to pull material from the surface of the normal star during a process referred too as accretion. Astronomers have designated this new x-ray pulsar Swift J1749.4-2807 and believe it’s the remnant of a supernova. Spinning wildly out of control, this accretion-powered pulsar is thought to be composed of dense material with properties we know nothing about.
Astronomers believe the signal emanating from the constellation Sagittarius the Archer was produced during the accretion process as the material torn from the surface of the normal star spirals around the neutron star. NASA scientists believe the material heats up to the point where it radiates x-rays during the process of spiralling into the region of the neutron star’s magnetic poles. X-ray detectors on near Earth telescopes detect these x-rays when a spinning neutron star lines up directly with the line of sight to Earth.
Check out astronomy.com or NASA for the latest in breaking news on the human journey to the beginning of space and time.
Click this link to watch a You Tube video on Sagittarius the Archer
Astronomy News – The human “Journey to the Beginning of Space and Time’ discovered another neutron star on June 5, 2009, that’s currently keeping astronomers and space scientists busy looking into the unusual properties of this newest member of the pulsar zoo. Astronomers using NASA’s Chandra, Swift and Rossi X-ray observatories, the Fermi Gamma-ray Space Telescope and ESA’s XMM-Newton telescope have been taking a look at this slowly rotating neutron star with an ordinary surface magnetic field as it gives off x-rays and gamma rays. Astronomers think the facts they have collected during their study of neutron star SGR 0418+5729 could indicate the presence of an internal magnetic field much more powerful than the surface magnetic field of this pulsar. This has definite implications in relation to the evolution of the most powerful magnets we have observed during the human “Journey to the Beginning of Space and Time” and astronomers are now delving into the mysteries they see within this neutron star to determine the facts.
Another strange neutron star
Astronomers looking at neutron star SGR 0418+5729 think this pulsar is one of a strange breed of neutron stars they refer too as magnetars, which normally have strong to extreme magnetic fields 20 to 100 times above the average for galactic radio pulsars they have viewed in the universe. What really has astronomers viewing SGR 0418+5729 scratching their heads is the fact that over a 490 day period of observing this pulsar astronomers saw no detectable decrease in this neutron stars rotational rate.
Astronomers think that the lack of rotational slowing of this neutron star could mean that the radiation of low-frequency waves is pretty weak, which leads them to believe the surface magnetic field of this pulsar must be quite a bit less powerful than normal. This conclusion gives astronomers another puzzle to solve, since with this thought astronomers are wondering where the energy for this neutron stars power bursts and x-ray emissions come from.
Does the power and energy creating this neutron stars power bursts and x-ray emissions originate in the twisting and amplifying of this pulsars internal magnetic field in the chaotic interior of this neutron star?
Present theories on this indicate that astronomers believe that if the internal magnetic field becomes ten or more times stronger than the surface magnetic field, the twisting or decay of the magnetic field could lead to the production of steady and bursting x-rays through the heating of the pulsar’s crust or the acceleration of particles in the magnetic field.
The question astronomers want to answer now is how large can the imbalance between the surface and interior magnetic fields be? If further observations indicate that the surface magnetic field limit is pushed too low, then astronomers will have to dig a little deeper into SGR 0418+5729 to find out why this neutron star is rotating slower.
Astronomy News – Browsing through a popular and well-read book on astronomy from the 1980s, one might get the idea astronomers have pierced the veil of secrecy surrounding stellar bodies we refer to as neutron stars. Astronomers and stargazers have boarded their time-machine-to-the-stars to journey to exotic parts of space and time to view these strange celestial bodies for decades. Astronomers have been studying the central body of the Crab Nebula for hundreds of years, watching as it emits regular apparent emissions in the direction of Earth about 30 times per second as it rotates, in what astronomers have described as a lighthouse effect.
The description of neutron stars in astronomy books from the 1980s isn’t necessarily incorrect, but research in the intervening years has led scientists to believe astronomy books need to be rewritten in parts and filled in a bit more. Astronomers now believe that neutron stars aren’t all born crab-like and that this scenario is only one of a menagerie of weird and unusual celestial objects they refer to as neutron stars. A menagerie of bizarre stellar bodies representing a significant percentage of the total population of neutron stars they have viewed during the human “Journey to the Beginning of Space and Time.”
Astronomers have found weird and wonderful things that astound and amaze
The menagerie of stellar bodies astronomers are bringing into the pulsar zoo are weird characters, with names like magnetars, anomalous x-ray pulsars, rotating radio transients, compact central objects, and soft gamma repeaters, and properties, unlike the famous Crab Nebula. All of these characters constitute at least ten percent of the total population of neutron stars observed and they could represent a much higher percentage. I guess it’s time to rewrite the astronomy books!
What kind of characters will you find in the pulsar zoo? All of the characters you’ll view in the pulsar zoo have a few common and bizarre properties. They all have masses upwards of half a million Piles of earth crammed into a sphere about 12 miles in diameter. The second most compact objects astronomers have viewed during the human “Journey to the Beginning of Space and Time”, at the center of a neutron star lies a reality we as humans have yet to comprehend, with densities, at least, ten times the densities scientists have recorded inside the atomic nucleus. The laws of nature in this environment are beyond anything we as humans can truly understand at present, but neutron stars also have other properties.
Astronomers continue to study neutron stars in amazement and wonder
Neutron stars also rotate at a tremendously fast rate and astronomers have brought neutron stars to the pulsar zoo that rotate 700 times per second. A rate of rotation that despite the pull of gravity on the surface of this neutron star, is likely to create a slightly pancake-shaped body, due to the extreme rate of rotation of this neutron star. The question now is just how fast can a neutron star rotate?
What are some of the less common properties of the most bizarre members of the pulsar zoo? We’ll take you through the pulsar zoo on another day and show you some of these weird and unusual celestial bodies. Until then, “Live long and prosper”.