Solar Tornadoes January 10, 2007Posted by jtintle in Space Fotos, Sun.
Tags: Fred Hoyle, G. Scharmer, L. Rouppe van der Voort, penumbra, Reel EFX. Inc, Solar Tornado, Sun, Sunspots, SVST
left, G. Scharmer, L. Rouppe van der Voort (KVA ) et al., SVST: right, copyright 2001, Reel EFX. Inc
As Fred Hoyle long ago pointed out; the Sun does not conform to the expected behavior of an internally heated ball of gas, simply radiating its energy into space. Instead, its behavior at every level is complex and baffling. Nowhere is it more mysterious than in a sunspot.
Sunspots are strange blemishes on the face of the Sun that offer some of the strongest evidence against the Sun being powered internally. They are conventionally described as being a result of strong magnetic fields pinching off the convection of heat from inside the Sun before it can reach the surface.
The electric star interpretation is that sunspots are breaks in the hot surface of the sun, through which we can get a glimpse of the underlying layers. To satisfy the standard theory, these deeper layers of the Sun should be hotter to drive the so-called vigorous convection. But they aren’t. The dark center of the sunspot, or umbra, is 20% cooler than the rest of the surface of the Sun.
The outer shadow of the sunspot, or penumbra, and the structure and behavior of the filaments that form the penumbra are also too complex to be explained by standard stellar theory.
There is a temptation for plasma researchers to simply equate the penumbral filaments with gargantuan lightning bolts, but the features do not match all that well. A typical lightning flash lasts for 0.2 seconds and covers a distance of about 10 km. The penumbral filaments last for at least one hour and are of the order of 1000 km long. If we could scale a lightning bolt 100 times we might have a flash that lasted between 20 and 200 seconds and was 1000 km long. The lifetime is too short. Also, measurements of scars on lightning conductors show that the lightning channel is only about 5 mm wide. Scaling that by 100 times would have solar lightning channels far below the limit of telescopic resolution
However, there is another familiar form of atmospheric electric discharge that does scale appropriately and could explain the mysterious dark cores of penumbral filaments. It is the tornado! Tornadoes last for minutes and can have a diameter of the order of one kilometer. Scale those figures up 100 times and we match penumbral filaments very well. And if the circulating cylinder of plasma is radiating heat and light, as we see on the Sun, then the solar “tornado” will appear, side on, to have bright edges and a dark core (right image, above).
Famous Space Pillars Feel the Heat of Star’s Explosion January 9, 2007Posted by jtintle in Deep Space, Space Fotos.
Tags: Spitzer Space Telescope (SST), American Astronomical Society, Dr. Alberto Noriega-Crespo, Eagle Nebula, ESA, Hubble Space Telescope, Infrared Space Observatory, JPL-Caltech, NASA, Nicolas Flagey, Pillars of Creation, Spitzer Science Center, The Institut d'Astrophysique Spatiale
NASA/JPL-Caltech/N. Flagey (IAS/SSC) & A. Noriega-Crespo (SSC/Caltech)
The three iconic space pillars photographed by NASA’s Hubble Space Telescope in 1995 might have met their demise, according to new evidence from NASA’s Spitzer Space Telescope.
A new, striking image from Spitzer shows the intact dust towers next to a giant cloud of hot dust thought to have been scorched by the blast of a star that exploded, or went supernova. Astronomers speculate that the supernova’s shock wave could have already reached the dusty towers, causing them to topple about 6,000 years ago. However, because light from this region takes 7,000 years to reach Earth, we won’t be able to capture photos of the destruction for another 1,000 years or so.
Spitzer’s view of the region shows the entire Eagle nebula, a vast and stormy community of stars set amid clouds and steep pillars made of gas and dust, including the three well-known “Pillars of Creation.”
“I remember seeing a photograph of these pillars more than a decade ago and being inspired to become an astronomer,” said Nicolas Flagey of The Institut d’Astrophysique Spatiale in France. “Now, we have discovered something new about this region we thought we understood so well.” Flagey, a visiting graduate student at NASA’s Spitzer Science Center at the California Institute of Technology in Pasadena, presented the results today at the American Astronomical Society meeting in Seattle.
Astronomers have long predicted that a supernova blast wave would mean the end for the popular pillars. The region is littered with 20 or so stars ripe for exploding, so it was only a matter of time, they reasoned, before one would blow up. The new Spitzer observations suggest one of these stellar time bombs has in fact already detonated, an event humans most likely witnessed 1,000 to 2,000 years ago as an unusually bright star in the sky.
Whenever the mighty pillars do crumble, gas and dust will be blown away, exposing newborn stars that were forming inside. A new generation of stars might also spring up from the dusty wreckage.
Spitzer is a space telescope that detects infrared, longer-wavelength light that our eyes cannot see. This allows the observatory to both see the dust and see through it, depending on which infrared wavelength is being observed. In Spitzer’s new look at the Eagle nebula, the three pillars appear small and ghostly transparent. They are colored green in this particular view. In the largest of the three columns, an embedded star is seen forming inside the tip.
Above the pillars is the enormous cloud of hot dust, colored red in the picture, which astronomers think was seared by the blast wave of a supernova explosion. Flagey and his team say evidence for this scenario comes from similarities observed between this hot dust and dust around known supernova remnants. The dust also appears to have a shell-like shape, implying that a supernova blast wave is traveling outward and sculpting it.
The mysterious dust was first revealed in previous images from the European Space Agency’s Infrared Space Observatory, but Spitzer’s longer-wavelength infrared instrument was able to tentatively match the dust to a supernova event.
“Something else besides starlight is heating this dust,” said Dr. Alberto Noriega-Crespo, Flagey’s advisor at the Spitzer Science Center. “With Spitzer, we now have the missing long-wavelength infrared data that are giving us an answer.”
Kepler’s Supernova Remnant: A Star’s Death Comes to Life January 9, 2007Posted by jtintle in Deep Space, Space Fotos.
Tags: Chandra X-ray Observatory, Johannes Kepler, Kepler's supernova remnant, Milky Way Galaxy, NASA, NCSU, North Carolina State University - Raleigh, S. Reynolds, Supernova, white dwarf star
Using NASA’s Chandra X-ray Observatory, scientists have created a stunning new image of one of the youngest supernova remnants in the galaxy. This new view of the debris of an exploded star helps astronomers solve a long-standing mystery, with implications for understanding how a star’s life can end catastrophically and for gauging the expansion of the universe.
Over 400 years ago, sky watchers — including the famous astronomer Johannes Kepler — noticed a bright new object in the night sky. Since the telescope had not yet been invented, only the unaided eye could be used to watch as a new star that was initially brighter than Jupiter dimmed over the following weeks.
Chandra’s latest image marks a new phase in understanding the object now known as Kepler’s supernova remnant. By combining nearly nine days of Chandra observations, astronomers have generated an X-ray image with unprecedented detail of one of the brightest recorded supernovas in the Milky Way galaxy.
The explosion of the star that created the Kepler remnant blasted the stellar remains into space, heating the gases to millions of degrees and generating highly energized particles. Copious X-ray light, like that shining from many supernova remnants, was produced.
Astronomers have studied Kepler intensively over the past three decades with radio, optical and X-ray telescopes, but its origin has remained a puzzle. On the one hand, the presence of large amounts of iron and the absence of a detectable neutron star points toward a so-called Type Ia supernova. These events occur when a white dwarf star pulls material from an orbiting companion until the white dwarf becomes unstable and is destroyed by a thermonuclear explosion.
On the other hand, when viewed in optical light, the supernova remnant appears to be expanding into dense material that is rich in nitrogen. This would suggest Kepler belongs to a different type of supernova (known as “Type II”) that is created from the collapse of a single massive star that sheds material before exploding. Type Ia supernovas do not normally have such surroundings.
A team of astronomers, led by Stephen Reynolds of North Carolina State University in Raleigh, N.C., was able to use the Chandra dataset to address this mystery. By comparing the relative amounts of oxygen and iron atoms in the supernova, the scientists were able to determine that Kepler resulted from a Type Ia supernova.
In solving the mystery of Kepler’s identity, Reynolds and his team have also given an explanation for the dense material in the remnant. Kepler could be the nearest example of a relatively rare “prompt” Type Ia explosion, which occur in more massive progenitors only about 100 million years after the star formed rather than several billion years. If that is the case, Kepler could teach astronomers more about all Type Ia supernovas and the ways in which prompt explosions from massive stars differ from their more common cousins associated with lower mass stars. This information is essential to improve the reliability of the use of Type Ia stars as “standard candles” for cosmological studies of dark energy as well as to understand their role as the source of most of the iron in the universe.
In the new Chandra Kepler image, red represents low-energy X-rays and shows material around the star — dominated by oxygen — that has been heated up by a blast wave from the star’s explosion. The yellow color shows slightly higher energy X-rays, mostly iron formed in the supernova, while green (medium-energy X-rays) shows other elements from the exploded star. The blue color represents the highest energy X-rays and shows a shock front generated by the explosion.
Hubble’s view of N90 star-forming region January 9, 2007Posted by jtintle in Deep Space, Space Fotos.
Tags: Hubble Heritage (STScI/AURA)-ESA/Hubble Collaboration, N90, NASA, Nebula, Small Magellanic Cloud
NASA, ESA and the Hubble Heritage Team (STScI/AURA)-ESA/Hubble Collaboration
This Hubble image image depicts bright blue newly formed stars that are blowing a cavity in the centre of a fascinating star-forming region known as N90.
The high energy radiation blazing out from the hot young stars in N90 is eroding the outer portions of the nebula from the inside, as the diffuse outer reaches of the nebula prevent the energetic outflows from streaming away from the cluster directly. Because N90 is located far from the central body of the Small Magellanic Cloud, numerous background galaxies in this picture can be seen, delivering a grand backdrop for the stellar newcomers. The dust in the region gives these distant galaxies a reddish-brown tint.
A Cosmic Egg January 9, 2007Posted by jtintle in Deep Space, Space Fotos.
Tags: Hubble Heritage (STScI/AURA)-ESA/Hubble Collaboration, IC 418, NASA, Nebula, R. Sahai, The Electric Universe
R. Sahai et al., Hubble Heritage Team/AURA, NASA
This cosmic egg (planetary nebula IC 418) is not the uniform spherical shell of gas blown off by a dying star that conventional theories expect.
Both the shell and the inner “yolk” (blue) are stretched along an axis, and both are finely divided into cells that are surrounded by glowing filaments of matter. The central star varies in brightness over several hours, and conventional theorists speculate that it may generate “chaotic winds” that might somehow crisscross to create the cells and filaments.
The Electric Universe sees a different egg. Shell and “yolk” are both composed of plasma, not of gas. The physics of electric currents apply, not the physics of winds. The shell is a plasma sheath, a “double layer” that acts like a capacitor, mediating the different electrical fields inside and outside the shell. Most of the voltage difference between the star and the surrounding galactic field is taken up in that thin, membrane-like double layer. The blue “yolk” is another, secondary, double layer that forms when the electric current feeding the central star reaches a threshold density.
As is typical with sheaths, currents flow along the surface. And as is typical with plasma, the currents pinch into filaments that pull in material from surrounding spaces. The double layers and their current filaments also respond to the electromagnetic forces of the interstellar current filament feeding the system and are thus elongated along the axis of that current. That larger current flows in a circuit that threads through the galaxy. It is invisible because of its lower current density, but the magnetic field it produces is detectable in the squeezing and stretching of the egg that derives from it.
That the power output of the central star varies over a few hours indicates that the power input is oscillating. Some feedback mechanism in the supply circuit has reached a resonant condition. That element of the circuit need not be in the star or nebula but could be far away, just as the circuit elements in a radio that generate the oscillating radio wave may be far removed from the antenna that radiates the energies.
Ash cloud behind St Georges Hill January 8, 2007Posted by jtintle in Planets, Space Fotos.
Tags: Belham River Valley, Cork Hill, Gages Mountain, Gages Valley, Garibaldi Hill, Montserrat Volcano Observatory, St Georges Hill, Tyres Ghaut, Volcano
The event onset was recorded on the MVO seismic network at 05:54. Between 06:05-07 there was explosive activity audible as far north as Woodlands in Montserrat (seismically better described as “jetting”; 3 distinct pulses were recorded). The rising ash cloud was visible from all over Montserrat moving out to the WSW south of St Georges Hill and Garibaldi Hill.
Pyroclastic flows travelled down Gages Valley and Tyres Ghaut into the head of the Belham River Valley simultaneously suggesting source high on dome directly behind Gages Mountain. At 06:15 the largest pyroclastic flow to date flow entered the Belham Valley, reaching as far as the edge of Cork Hill, a run out distance of around about 5 km. At 06:25 the ash cloud was reported to have reached 30,000 ft.
Between 06:20-06:25 seismic activity began to wane and by 06:30 seismicity had returned to just above background, dominated by isolated PF signals (extended duration rockfall signals, none or which was especially large, and definitely not suggestive of a collapse) and small long period earthquakes. Pyroclastic activity in Tyres Ghaut continued at higher levels than recent days over the next approx. 1.5 hours establishing an almost regular 7 minute cycle. The run out distances of the individual flows were limited to 1-1.5 km, and each flow was preceded by a minor pulse of ash venting.
At about 08:20 a short period of rumbling/roaring preceding pulse ash venting.
By 09:30 seismicity had returned to background levels.
Pyroclastic activity is ongoing on the NW sector of the volcano with small flows in Tyres Ghaut, run out distances up to 1.5 km.
Low-level ash and steam venting continus from a vent high up on the western side of the lava dome.
Fortunately the prevailing wind carried ash out to the WSW at lower levels (<about 15,000 ft) and at higher level to the ESE, so northern Montserrat remains unaffected by any significant ashfall from this event.
Preliminary observations of the dome suggest that very little material has been removed, although the dome about the head of Tyres Ghaut appears to have been eaten back to form a chute, possibly making it easier for large volumes of dome material to enter Tyres Ghaut (and Belham Valley) during future events.
I know this isn’t a Space photo but I thought this was a cool image
The Trapezium region in M42 January 8, 2007Posted by jtintle in Deep Space, Space Fotos.
Tags: Anglo-Australian Observatory, David Malin, M42, Nebula, Orion Nebula, Trapezium cluster
Image and text © 1979-2002, Anglo-Australian Observatory, photograph by David Malin.
The central ‘star’ of the three groups forming the asterism of Orion’s sword is in reality a nebula, and is clearly nebulous to the unaided eye. At the heart of the most luminous nebulosity shimmer a handful of stars known as the Trapezium cluster, visible in binoculars. These are the brightest members of a substantial cluster of stars , most of which are still hidden in the dusty recesses of the Orion nebula against which they are seen. The stars of the Trapezium provide much of the energy which makes the brilliant Orion Nebula visible and are at a distance of about 1500 light years. This image was made with three, 30-second exposures at the prime focus of the the Anglo-Australian Telescope.
Part of M78, NGC 2068 in Orion January 8, 2007Posted by jtintle in Deep Space, Space Fotos.
Tags: Anglo-Australian Observatory, C. Tinney, D. Malin, Herbig-Haro objects, M78, Messier, Nebula, NGC 2068, Orion Nebula, Orion's Belt, reflection neblua, S. Lee
Image and text © 1999-2002, Anglo-Australian Observatory, Photograph by S. Lee, C. Tinney and D. Malin.
In a modest telescope M78 looks like a faint comet, exactly the kind of object Messier intended to include in his catalog to avoid confusion with the real thing. The same telescope will also reveal two stars of similar apparent brightness (about 10th magnitude) embedded in the nebula. It is light from these stars reflected by dust grains that is responsible for the nebulosity, and a look at our color picture shows that the whole field is shrouded in dust.
M78 is thus a reflection nebula, one of the brightest in the sky. But the conjunction of the two obvious stars and dust is not an accident. They are the brightest members of a small cluster of stars forming inside the dusty cloud. These are mostly invisible at optical wavelengths but some signs of them are evident in the two small, reddish nebulae towards the lower center and extreme lower left (SW) of the frame. These are Herbig-Haro objects, rapidly-moving jets ejected at an early stage in the formation of stars. Where such jets emerge from the dense dust they advertise recent star formation.
3D distribution of dark matter in the Universe January 8, 2007Posted by jtintle in Deep Space, Space Fotos.
Tags: California Institute of Technology, Dark Matter, ESA, Hubble Space Telescope, NASA, R. Massey, XMM-Newton X-ray observatory
NASA, ESA and R. Massey (California Institute of Technology)
This three-dimensional map, obtained thanks to HST and XMM-Newton data, offers a first look at the web-like large-scale distribution of dark matter, an invisible form of matter that accounts for most of the Universe’s mass.
The map reveals a loose network of dark matter filaments, gradually collapsing under the relentless pull of gravity, and growing clumpier over time.
The three axes of the box correspond to sky position (in right ascension and declination), and distance from the Earth increasing from left to right (as measured by cosmological redshift). Note how the clumping of the dark matter becomes more pronounced, moving right to left across the volume map, from the early Universe to the more recent Universe.
Discovery Touches Down January 7, 2007Posted by jtintle in Planets, Space Fotos.
Tags: Christer Fuglesang, Joan Higginbotham, Kennedy Space Center, Mark Polansky, NASA, Nicholas Patrick, Robert Curbeam, Space Shuttle Discovery, STS-116, Thomas Reiter, William Oefelein
Space Shuttle Discovery touches down on an illuminated Runway 15 at NASA Kennedy Space Center’s Shuttle Landing Facility as the sun sets on the shortest day of the year, concluding mission STS-116. Main gear touchdown was at 5:32 p.m. EST. Nose gear touchdown was at 5:32:12 p.m. and wheel stop was at 5:32:52 p.m. At touchdown — nominally about 2,500 ft. beyond the runway threshold — the orbiter is traveling at a speed ranging from 213 to 226 mph. Discovery traveled 5,330,000 miles, landing on orbit 204. Mission elapsed time was 12 days, 20 hours, 44 minutes and 16 seconds. This is the 64th landing at KSC. Aboard Discovery are Commander Mark Polansky, Pilot William Oefelein, and Mission Specialists Robert Curbeam, Joan Higginbotham, Nicholas Patrick and Christer Fuglesang, who represents the European Space Agency, as well as Thomas Reiter, who is returning from a 6-month stay on the International Space Station. During the mission, three spacewalks attached the P5 integrated truss structure to the station, and completed the rewiring of the orbiting laboratory’s power system. A fourth spacewalk retracted a stubborn solar array.