Black Hole with Accretion Disk and Binary Jets

Artist's impression of a black hole feasting on matter from its companion star in a binary system. Matter flows from the star towards the black hole and forms an accretion disc with a temperature so high that it emits X-rays. The black hole can be a fussy eater: instead of swallowing all of the material, it sometimes pushes a fraction of it away in the form of two powerful jets of particles.

A team of astronomers studying the jets of the binary system 4U1630-47 have confirmed that black hole jets not only consist of electrons but also contain heavier particles, like protons or atomic nuclei. This means that jets can carry mass and energy away from the black hole in much larger amounts than previously thought.

Illustration credit: ESA/ATG Medialab

Note: For more information, see Black Hole Boasts Heavyweight Jets and Black Hole with Disc and Jets.

NGC 6537

This image shows an example of a bipolar planetary nebula known as NGC 6537 taken with the New Technology Telescope at ESO’s La Silla Observatory. The shape, reminiscent of a butterfly or an hourglass, was formed as a Sun-like star approached the end of its life and puffed its outer layers into the surrounding space. For bipolar nebulae, this material is funneled towards the poles of the aging star, creating the distinctive double-lobed structure.

Observations using the NTT and Hubble have found that bipolar planetary nebulae located towards the central bulge of our Milky Way appear to be strangely aligned in the sky — a surprising result given their varied and chaotic formation.

NGC 6537, which lies much closer to the Earth, was not part of the new study.

Image credit: ESO

Note: For more information, see Bizarre Alignment of Planetary Nebulae. See also Bizarre Alignment of Planetary Nebulae.

GX 339-4 Black Hole Binary System

This artist's impression shows the GX 339-4 binary system, which consists of a 7-solar-mass black hole that accretes mass from its companion, a low-mass star, shown on the left. The process takes place via an accretion disc and also triggers the release of powerful jets of highly-energetic particles.

Different regions in the jets and disc emit radiation at different wavelengths: the base of the jets, closer to the black hole, emit light at shorter wavelengths (infrared, shown here in yellow) than the extremity of the jets, which shine brightly in radio waves (shown here in red). Similarly, the most central part of the disc, closer to the black hole, shines brightly in X-rays (shown here in violet), whereas the outer parts shine most brightly at longer wavelengths (ultraviolet and optical, shown here in blue).

Observations performed using ESA's Herschel space observatory have provided the first view of GX 339-4 at far-infrared wavelengths, allowing astronomers to probe the jets down to their base, where the far-infrared emission originates. This is an important addition to the understanding of black-hole jets and of the physical processes that take place very close to a black hole.

Illustration credit: SA/ATG medialab

Note: For more information, see Herschel Gets to the Bottom of Black-Hole Jets.

HH 151

This image shows an object known as HH 151, a bright jet of glowing material trailed by an intricate, orange-hued plume of gas and dust. It is located some 460 light-years away in the constellation of Taurus (The Bull), near to the young, tumultuous star HL Tau.

In the first few hundred thousand years of life, new stars like HL Tau pull in material that falls towards them from the surrounding space. This material forms a hot disc that swirls around the coalescing body, launching narrow streams of material from its poles. These jets are shot out at speeds of several hundred kilometers per second and collide violently with nearby clumps of dust and gas, creating wispy, billowing structures known as Herbig-Haro objects — like HH 151 seen in the image above.

Such objects are very common in star-forming regions. They are short-lived, and their motion and evolution can actually be seen over very short timescales, on the order of years. They quickly race away from the newly-forming star that emitted them, colliding with new clumps of material and glowing brightly before fading away.

Image credit: ESA/Hubble & NASA. Acknowledgement: Gilles Chapdelaine

Sharpless 140

In the quest to better understand the birth of stars and the formation of new worlds, astronomers have used NASA's Spitzer Space Telescope to examine the massive stars contained in a cloudy region called Sharpless 140. This cloud is a star-forming microcosm that exhibits, within a relatively small area, all of the classic manifestations of stellar birth.

Sharpless 140 lies almost 3,000 light-years from Earth in the constellation Cepheus. At its heart is a cluster of three deeply embedded young stars, which are each several thousand times brighter than the Sun. Though they are strikingly visible in this image from Spitzer's infrared array camera, they are completely obscured in visible light, buried within the core of the surrounding dust cloud.

The extreme youth of at least one of these stars is indicated by the presence of a stream of gas moving at high velocities. Such outflows are signatures of the processes surrounding a star that is still gobbling up material as part of its formation.

The bright red bowl, or arc, seen in this image traces the outer surface of the dense dust cloud encasing the young stars. This arc is made up primarily of organic compounds called polycyclic aromatic hydrocarbons, which glow on the surface of the cloud. Ultraviolet light from a nearby bright star outside of the image is "eating away" at these molecules. Eventually, this light will destroy the dust envelope and the masked young stars will emerge.

This false-color image was taken on October 11, 2003.

Photo credit: NASA/JPL-Caltech

The Egg Nebula

The NASA/ESA Hubble Space Telescope has been on the forefront of research into the lives of stars like our Sun. At the ends of their lives, these stars run out of nuclear fuel in a phase that is called the preplanetary or protoplanetary nebula stage. This Hubble image of the Egg Nebula shows one of the best views to date of this brief, but dramatic, phase in a star’s life.

During the preplanetary nebula phase, the hot remains of an aging star in the center of the nebula heat it up, excite the gas and make it glow over several thousand years. The short lifespan of preplanetary nebulae means there are relatively few of them in existence at any one time. Moreover, they are very dim, requiring powerful telescopes to be seen. This combination of rarity and faintness means they were only discovered comparatively recently. The Egg Nebula, the first to be discovered, was first spotted less than 40 years ago, and many aspects of this class of object remain shrouded in mystery.

At the center of this image, and hidden in a thick cloud of dust, is the nebula’s central star. While scientists can’t see the star directly, four searchlight beams of light coming from it shine out through the nebula. Researchers hypothesize that ring-shaped holes in the thick cocoon of dust, carved by jets coming from the star, let the beams of light emerge through the otherwise opaque cloud. The precise mechanism by which stellar jets produce these holes is not known, but one explanation is that a binary star system, rather than a single star, exists at the center of the nebula.

The onion-like layered structure of the more diffuse cloud surrounding the central cocoon is caused by periodic bursts of material being ejected from the dying star. The bursts typically occur every few hundred years.

This image is produced from exposures in visible and infrared light from Hubble’s Wide Field Camera 3.

Photo credit: ESA/Hubble, NASA

Black Hole Rips Apart a Star

PS1-10jh: A galaxy about 2.7 billion light years from Earth with a supermassive black hole at its center.

This computer-simulated image shows gas from a star that is ripped apart by tidal forces as it falls into a black hole. Some of the gas also is being ejected at high speeds into space. Observations from multiple telescopes, including NASA's Chandra X-ray Observatory, were used to determine the most direct evidence yet of a star being ripped apart by a supermassive black hole. Chandra's X-ray data were critical in ruling out the other contending possibility that this galaxy instead contained a so-called active galactic nucleus.

Illustration credit: NASA, S. Gezari (The Johns Hopkins University), and J. Guillochon (University of California, Santa Cruz); video credit: NASA, S. Gezari (The Johns Hopkins University), and J. Guillochon (University of California, Santa Cruz)

Note: This is the current big story. For more information, see PS1-10jh: Black Hole Caught Red-handed in a Stellar Homicide . Also, see:
* Black Hole Caught Red-Handed in a Stellar Homicide
* PIA15429: Black Hole Erupts
* PIA15620: Black Hole Swallows a Star

M2-9, The Butterfly Nebula, by SOFIA

Researchers using NASA's Stratospheric Observatory for Infrared Astronomy (SOFIA) have captured infrared images of the last exhalations of a dying sun-like star.

The object observed by SOFIA, planetary nebula Minkowski 2-9, or M2-9 for short, is seen in this three-color composite image. The SOFIA observations were made at the mid-infrared wavelengths of 20, 24, and 37 microns. The 37-micron wavelength band detects the strongest emissions from the nebula and is impossible to observe from ground-based telescopes.

Objects such as M2-9 are called planetary nebulae due to a mistake made by early astronomers who discovered these objects while sweeping the sky with small telescopes. Many of these nebulae have the color, shape and size of Uranus and Neptune, so they were dubbed planetary nebulae. The name persists despite the fact that these nebulae are now known to be distant clouds of material, far beyond our solar system, that are shed by stars about the size of our sun undergoing upheavals during their final life stages.

Although the M2-9 nebular material is flowing out from a spherical star, it is extended in one dimension, appearing as a cylinder or hourglass. Astronomers hypothesize that planetary nebulae with such shapes are produced by opposing flows of high-speed material caused by a disk of material around the dying star at the center of the nebula. SOFIA's observations of M2-9 were designed to study the outflow in detail with the goal of better understanding this stellar life cycle stage that is important in our galaxy's evolution.

"The SOFIA images provide our most complete picture of the outflowing material on its way to being recycled into the next generation of stars and planets," said Michael Werner of NASA's Jet Propulsion Laboratory (JPL) in Pasadena, California, principal investigator of these observations. "We were gratified to see the lobes so clearly using SOFIA. These early results demonstrate the scientific potential of this important new observatory."

The observations were made using the Faint Object Infrared Camera for the SOFIA Telescope (FORCAST) instrument in June 2011 by a team consisting of astronomers from JPL, the California Institute of Technology, the University of California at Los Angeles, Cornell University and Ithaca College, Ithaca, N.Y. Preliminary analyses of these data were first presented in January 2012 at the American Astronomical Society meeting in Austin, Texas.

The SOFIA observatory combines an extensively modified Boeing 747SP aircraft and a 17-metric-ton reflecting telescope with an effective diameter of 2.5 meters (100 inches) to altitudes as high as 45,000 feet (14 km), above more than 99 percent of the water vapor in Earth's atmosphere that blocks most infrared radiation from celestial sources.

Photo credit: NASA/DLR/USRA/DSI/FORCAST Team

Twin Jets in Herbig-Haro 34

NASA's Spitzer Space Telescope took this image of a baby star sprouting two identical jets (green lines emanating from fuzzy star). The jet on the right had been seen before in visible-light views, but the jet at left -- the identical twin to the first jet -- could only be seen in detail with Spitzer's infrared detectors. The left jet was hidden behind a dark cloud, which Spitzer can see through.

The twin jets, in a system called Herbig-Haro 34, are made of identical knots of gas and dust, ejected one after another from the area around the star. By studying the spacing of these knots, and knowing the speed of the jets from previous studies, astronomers were able to determine that the jet to the right of the star punches its material out 4.5 years later than the counter-jet.

The new data also reveal that the area from which the jets originate is contained within a sphere around the star, with a radius of 3 astronomical units. An astronomical unit is the distance between Earth and the Sun. Previous studies estimated that the maximum size of this jet-making zone was 10 times larger.

The wispy material is gas and dust. Arc-shaped bow shocks can be seen at the ends of the twin jets. The shocks consist of compressed material in front of the jets.

The Herbig-Haro 34 jets are located at approximately 1,400 light-years away in the Orion constellation.

Photo credit: NASA/JPL-Caltech

Eta Carinae

This new image of the luminous blue variable Eta Carinae was taken with the NACO near-infrared adaptive optics instrument on ESO's Very Large Telescope, yielding an incredible amount of detail. The images clearly shows a bipolar structure as well as the jets coming out from the central star. The image was obtained by the Paranal Science team and processed by Yuri Beletsky (ESO) and Hännes Heyer (ESO). It is based on data obtained through broad (J, H, and K; 90 second exposure time per filters) and narrow-bands (1.64, 2.12, and 2.17 microns; probing iron, molecular and atomic hydrogen, respectively; 4 min per filter).

Photo credit: ESO

Cygnus X-1

This illustration depicts the X-ray binary Cygnus X-1, composed of a 35 Msun blue O9 supergiant star and a black hole with a mass of about 10 Msun.

With its intense gravitational field, the black hole draws matter from its companion, and the stripped material spirals around the black hole, forming an accretion disc. Friction in the disc heats the material up to millions of degrees, making it shine in X-rays. Furthermore, the rotation of the disc funnels part of the accreted material into highly collimated, bipolar jets of particles that are released at relativistic speeds.

Based on the existing link between accretion and ejection of matter in X-ray binaries, astronomers also refer to these objects as 'microquasars' because they appear as miniature versions of quasars - the nuclei of active galaxies.

Illustration credit: ESA

Note: "Msun" means "solar mass," the mass of our sun. It is a common measurement to compare the sizes of stars. For more information, see INTEGRAL Discovers Gamma Rays Originating From Black Hole Jets.

NGC 1514

This image composite shows two views of a puffy, dying star, or planetary nebula, known as NGC 1514. The view on the left is from a ground-based, visible-light telescope; the view on the right shows the object in infrared light, as seen by NASA's Wide-field Infrared Survey Explorer, or WISE.

The object is actually a pair of stars -- one star is a dying giant somewhat heavier and hotter than our Sun, and the other was an even larger star that has now contracted into a dense body called a white dwarf. As the giant star ages, it sheds some its outer layers of material to form a large bubble around the two stars. Jets of material from the white dwarf are thought to have smashed into this bubble wall. The areas where the jets hit the cavity walls appear as orange rings in the WISE image. This is because dust in the rings is being heated and glows with infrared light that WISE detects.

The green cloud seen in the WISE view is an inner shell of previously shed material. In the visible image, this shell is seen in bright, light blues. An outer shell can also be seen in the visible image in more translucent shades of blue. This outer shell is too faint to be seen by WISE.

NGC 1514 is located 800 light-years away, in the constellation Taurus.

In the WISE image, infrared light with a wavelength of 3.4 microns is blue; 4.6-micron light is cyan; 12-micron light is green; and 22-micron light is red.

The visible-light image is from the Digitized Sky Survey, based at the Space Telescope Science Institute in Baltimore, Maryland.

Photo credits: NASA/JPL-Caltech/UCLA/DSS; NASA/JPL-Caltech/UCLA

Note: For more information on the bottom photo, see PIA13445: Cosmic Ocean Dweller.