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Sorry about the scarcity of posts last week.  Ferrebeekeeper opted to enjoy an extended Fourth of July by trying not to look at the internet (which paints a less-than-rosy picture of these (dis)United States of America).  I was out experiencing summer fun in the real world.  But that doesn’t mean we have forgotten about fireworks of the past.   We have just moved our perspective farther afield.

Above is the highest resolution image of Eta Carinae taken by the NASA/ESA Hubble Space Telescope.  Between 1838 and 1844 Eta Carinae nearly went supernova and briefly became the fourth brightest star in the heavens (well really the explosion/ejection event occurred 7500 years earlier and the photons only reached Earth in the mid-nineteenth century).  Astronomers are still arguing about what exactly transpired then in this messed up stellar system: one particularly dramatic theory is that the unstable blue super giant η Car A devoured a now unknown third star in the system!

In the actual universe Eta Carinae is almost certainly gone and a vast tsunami of strange electromagnetic radiation is rushing towards Earth…but nobody knows if this is true or when the supernova afterwash will get here.  Astronomers recently pointed Hubble at the Homunculus Nebula, the hourglass shaped cloud of matter which expands approximately one light year from the binary Eta Carinae system and took the color enhanced ultraviolet photo above. It is beautiful but ominous…let’s keep it in the back of our minds as we go about our little lives. This universe is a strange & savage place.

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More peculiar news from the heavens above (although I am not sure I I understand astrophysics well enough to articulate what makes it so strange).  Based on spectrographic analysis, scientists have identified a Type 2A supernova half-a-billion light years away “in” the constellation of Ursa Major. Unlike other supergiant supernovas of this category, the stellar explosion did not fade after 100 of our Earth days but continued to shine for 600 days—quite an explosion! (although explosions seen from 500 million light years away are already disquieting enough).  Also, supernova explosions are marked by spectral lines which reveal the dying star ejecting fast moving remnants—which are then followed by slower moving remnants.  In this case however there were no slower-moving remnants.

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A hint to what is going on with this star lies in the fact that it was apparently observed going supernova back in 1954 (although our observatories were much less sophisticated back then).  Perhaps IPTF14hls is a star which went partially supernova and then finally fully exploded in a bizarre and interesting way.  Maybe this foreshadows the fate of Eta Carinae—which I am sure is now gone.  I have always hoped we will see a stupendous supernova from Eta Carinae in my lifetime and this potentially bodes well.  However it also suggests that scientists need to work on their supernova behavior and prediction models.

plxzb4bljxuptdmu37y6This strange object which resembles a bottle gourd is actually a depiction of the largest yellow star known to science. HR5171A is located 11,700 light years from Earth in the heart of Centaurus (a southern constellation).  Actually the image above is two stars: HR5171A is part of a binary system and its companion star is so close that the topology of the hypergiant is affected. The smaller companion is not visible.  To quote Universe Today, “what we see is not the companion itself, but the regions gravitationally controlled and filled by the wind from the hypergiant.” It is uncanny how the giant star looks like a 1930s cartoon character’s head!  The combined system has a total mass 39 times that of our own sun, but their volume is vastly larger—nearly 1,300 times greater that that of the sun (and the luminosity of the star is a million times greater).  Although HR5171A is much less large than the true giants (like the astonishing Eta Carinae which has 120 solar masses), its ultimate fate is still not happy.  Yellow hypergiant stars are passing through a transitional phase on the way to going supernova (so enjoy it now, while you can).

A mosaic image taken by the Hubble Telescope of Messier 82 (NASA, ca. 2000)

A mosaic image taken by the Hubble Telescope of Messier 82 (NASA, ca. 2000)

Twelve million light years from Earth lies Messier 82, a starburst galaxy 5 times more luminous than the entire Milky Way galaxy.  Messier 82 (AKA M82) is a very happening and dynamic galaxy: stars are being created there at an exceptionally high rate—most likely because the galaxy is “interacting” (or possibly colliding) with its neighboring galaxy M81. In 2005, the Hubble Space Telescope detected nearly 200 massive starburst clusters near M82’s center. Within these huge masses of dust and gas, stars are being birthed (and dying) at an astonishing rate.  The high energy released by this cosmic upheaval is nearly constant and the outflow of charged particles from M82 is evocatively known as “superwind”.

Lovell Telescope, Jodrell Bank Observatory (Mike Peel; Jodrell Bank Centre for Astrophysics, University of Manchester)

In 2010, astronomers working at Jodrell Bank Observatory in England discovered a mystery at the heart of M82: an unknown object was emitting high energy electromagnetic radiation in a pattern unlike anything else so far observed in the universe.  The mystery object appeared to be moving at 4 times the speed of light (which is, of course, quite impossible according to the standard model of the universe.  Newscientist.com offered the following explanation (of sorts) for the mystery object’s perceived velocity:

Such apparent “superluminal” motion has been seen before in high-speed jets of material squirted out by some black holes. The stuff in these jets is moving towards us at a slight angle and travelling at a fair fraction of the speed of light, and the effects of relativity produce a kind of optical illusion that makes the motion appear superluminal.

At present, the best explanation astronomers have for the mystery is that it is some sort of microquasar or black hole which is interacting in an unusual way with the tumultuous mass within a starburst cluster.  At present, the mystery is unexplained.

A super-dramatic before-and-after animation of the type Ia supernova in M82

A super-dramatic before-and-after animation/photo of the type Ia supernova in M82

However, at present, M82 is doing entirely different things which have captured the attention of the international astronomy community.  On January 21st, 2014, Steve Fossey and a group of his students at University College London spotted a colossal explosion within M82.  The event was quickly identified as a type Ia supernova, a bright and consistently energetic star explosion which occurs in binary stars where at least one star is a white dwarf (the dead, but energetic fragment of a larger star).   CBS News explains the phenomenon and its historical significance:

[When a] white dwarf siphons off too much mass from its companion star, a runaway nuclear reaction begins inside the dead star, leading to a brilliant supernova. Because Type Ia supernovas are believed to shine with equal brightness at their peaks, they are used as “standard candles” to measure distances the universe.

The supernova in M82 is the nearest supernova of its type observed since Supernova 1987A was spotted in February 1987 in the Large Magellanic Cloud (the dwarf galaxy which is companion to the Milky Way).  Telescopes around Earth are turning towards Ursa Major (where M82 is located in the sky).  Although the supernova is big news here, it is a very stale story in M82 where this all happened 12 million years ago.

An Artist's Conception of a Type Ia Supernova

An Artist’s Conception of a Type Ia Supernova

An astronomy story has made big news headlines this week.  Usually most people are not unduly interested in the happenings in the heavens (either because such events are difficult to comprehend, or because they are regarded as remote to human interests), however this story does directly involve matters which humans take great interest in. gold-bar Scientists and theorists working for the Harvard-Smithsonian Center for Astrophysicists have announced a spectacular new theory concerning the origin of gold (and other heavy elements like platinum and uranium): the cosmologists believe that the heaviest natural elements are created when two neutron stars collide or when a neutron star collides with a black hole (here is an easy summary of neutron stars, extremely tiny supernova remnants with a mass greater than the sun).  Elements as complicated as iron are manufactured by normal stars in the course of their lifetime, however the creation of heavier elements is more mysterious.  Until now, chemists and physicists had imagined that gold, platinum, uranium, and what have you, come from supernovae—however computer models of various types of supernova events did not supporting that conjecture. The scientists at the Harvard-Smithsonian Center for Astrophysicists based their hypothesis partly on the massive gamma radiation burst detected on June 3rd, 2013 from 3.9 billion light years away in a galaxy located in the constellation Leo.  Gamma ray bursts tend to be associated with hypernovae/supernovae caused by the collapse of super-giant stars, but the June 3rd burst was different.  In certain rare circumstances, two neutron stars are in a binary system together.  Over time, the orbits decay and the stars come together in a cataclysmic event which releases energy tantamount to that of a supernova.    Based on the unusual exotic energy signatures of the June 3rd gamma ray burst,  it seems that scientists caught a rare peek at such an event.

Neutron Star Collision

Neutron Star Collision

I will confess that I am having trouble imagining two objects the size of small cities (yet each with a mass greater than the sun) slamming into each other at astronomical speeds.  Apparently such events only happen every 100,000 years or so in a galaxy the size of the Milky Way.  When the neutron stars come together, a black hole is ripped in the fabric of spacetime.  Huge parts of the neutron stars fall into the black hole and vanish from this universe, but other portions of the neutron stars (which, as the name hints, are made up largely of neutrons) are jettisoned into space.  Edo Berger, one of the astrophysicists who authored the new theory described the process with an earthy metaphor, saying, “several exciting things happen very quickly…. Most of the material collapses to form a black hole. Some of it is spewed into space. That material is rich in neutrons, which drives the formation of heavier and heavier elements, the way mud piles up on an off-road vehicle.” neutcol The gold, platinum, and heavy elements are created in astonishing mass (like many earths made entirely of gold).  The elements are diffused through the cosmos and become part of newly forming star systems. Gold is strange stuff anyway.  The gold present on Earth during its nebular formation is believed to have sunk deep into the center of planet’s molten core where it is inaccessible.  All the gold that rappers and kings wear (and that Ron Paul and draugers hoard) first began falling to Earth 200 million years after the planet’s final formation on asteroids.  The great gold strikes are well named: gold on the surface of Earth is there because of meteor strikes (although billions of years of geology have buried and twisted and hidden these cosmic remnants).

Yeehaw! There's asteroid fragments!

Yeehaw! There’s asteroid fragments!

Swift's X-Ray Telescope took this 0.1-second exposure of GRB 130427A at 3:50 a.m. EDT on April 27 (Credit: NASA/Swift/Stefan Immler)

Swift’s X-Ray Telescope took this 0.1-second exposure of GRB 130427A at 3:50 a.m. EDT on April 27 (Credit: NASA/Swift/Stefan Immler)

Gamma rays have the most energy of any wave in the electromagnetic spectrum (which includes more familiar radiation such as x-rays, radio, and visible light).  The wavelength of gamma rays (10 picometers and smaller–which is a subatomic scale) is less than that of any other sort of EM radiation.  Such radiation is created in the event horizons of massive black holes and during the destruction of gigantically massive stars. Comic book enthusiasts know gamma rays as the mysterious super force which created and empowers the incredible hulk, although actual cell biologists recognize gamma rays as ionizing radiation–supremely hazardous to living entities.

Artist's conception of a gamma-ray burst. (Credit: NASA.)

Artist’s conception of a gamma-ray burst. (Credit: NASA.)

On Saturday, April 27, the Fermi Gamma-Ray Telescope (a NASA satellite which orbits around Earth) detected a sudden brilliant surge of gamma radiation from the collapse of a super massive star in a galaxy 3.6 billion light-years away.  Gamma ray burst travel in vastly powerful beams which are very narrow–an effect which is a result of the shape of supernovae, as illustrated in the picture above.  Our old friend Eta Carinae has probably exploded and produced such a burst by now. A gamma ray bust from a nearby Wolf–Rayet star (any star with more than 20 solar masses) would most likely fry away life on our planet if it were aimed directly at Earth, but such explosions are increasingly rare as the universe ages.  Scientists can monitor gamma bursts from the edge of the universe (i.e. the distant past) but such a powerful event has never been monitored by our modern satellites and observatories from a middle range until now.

Antarctica’s IceCube Neutrino Observatory (Photo by Sven Lidstrom)

Antarctica’s IceCube Neutrino Observatory (Photo by Sven Lidstrom)

As the gamma ray burst fades (and the astronomy community begins to assess the initial data) other observatories will be on the lookout for the next wave of phenomena associated with the supernova.  Most of the energy of a supernova explosion is believed to be dissipated as neutrinos (esoteric subatomic particles which react very little with physical matter in this universe).  Fortunately humankind now possesses a sophisticated neutrino observatory on the South Pole where thousands of sensors are imbedded within a vast amount of Antarctic ice.  In the rare cases where neutrinos interact with matter, they produce a cascade of charged particles which can emit Cherenkov radiation (familiar as the spooky blue glow in a nuclear reactor).  Understanding the neutrino signature of such an event would potentially further our understanding of the physical parameters of existence.

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Also, a luminous flash of less energetic radiation (x-rays, radio waves, light, and so forth) should be following the gamma ray burst.  We understand these parts of supernovae better (since they are visible from many angles unlike the linear gamma ray bursts), but it should still be pretty–and round out our understanding of the full astronomical event.

Mind-blowing diagram comparing Vancouver to a Neutron Star (by Christian Joore)

Most items in the heavens are inconceivably large.  The sun, a fairly ordinary star has a diameter of 1,391,000 kilometers (864,327 miles).  Even a tiny planetoid like the moon has a diameter of 3,474 km (2,159 miles).  However a few noteworthy items in the heavens are so small that we can think of them in human terms—like neutron stars, which are the size of a town or small city with a diameter of only 20 or 30 kilometers (about ten to 15 miles  miles).   But even though they are the size of a small asteroid or Manhattan Island, neutron stars are hardly inconsequential.  These dinky stars can have more mass than the entire glorious sun (which itself is 332,946 times more massive than the Earth and everything on it).  A 1.27 cubic centimeter block of such material (approximately the size of a half an inch sugar cube) would weigh approximately the same as all of the human inhabitants of Earth (give or take).

Neutron stars are left-over fragments of supernovae explosions.  When a star 4 to 8 times more massive than our sun burns through all available fuel, its outer layers blow apart in a supernova which spreads glittering matter across great swaths of space.  The dense remaining portion of the stellar core undergoes a titanic battle between electron degeneracy pressure and gravity.  If the fragment has more than 1.44 stellar masses, gravity wins and the electrons and protons of its constituent matter are crushed into super dense neutrons.  Such explosions are tremendously dynamic and bright.  In 1054 AD, Sung dynasty astronomers recorded such an explosion which outshone the moon.  Contemporary astronomers have determined that the 1054 AD supernova created the Crab Nebula, an oval shaped mass of hydrogen, carbon, oxygen, nitrogen, neon, sulfur, and iron.

The Crab Nebula (which measures 11 light years across and lies 6,500 light-years from Earth) NASA/CXC/SAO/F. Seward

In the center of the Crab Nebula is a spinning neutron star which is emitting jets of particles at a tremendous velocity from its magnetic poles. These jets produce very powerful beams of electromagnetic radiation (which varies in intensity and wavelength according to elaborate nuclear & stellar physics, much of which is not yet understood).  The forces which create neutron stars often leave the stars spinning and pulsing with energy in such a way that they become pulsars.  These pulsars are useful for studying gravity, general relativity, and the behavior of matter at nuclear densities (albeit indirectly).  They also make accurate time measurement devices and useful beacons.  It is strange to think that stars so prominent for vast distances and so useful to astronomers actually have such minimal volume.

A Detailed x-ray image of the pulsar at the center of the Crab Nebula (Chandra)

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