New 3D Model Gives Insight On How Supernovas are Formed

Credit: Arnett, Meakin and Viallet/AIP Advances

A new model on how supernovas are formed was presented that can explain certain properties of supernovas that existing models cannot. The new model depicts the formation in three dimensions compared to previous one or two dimensional models.

In the new model, the material in the stars are violently mixed together which causes them to expand, contract, eject and then explode into a supernova. This 3D model is described in the article, "Chaos and turbulent nucleosynthesis prior to a supernova explosion" by David Arnett, Casey Meakin and Maxime Viallet which appears in the journal AIP Advances.

Supernovas are stars that run out of fuel or reaches critical mass and explodes. The explosion from a supernova can expel stellar materials at a rate of about 30,000 kilometers per second (10% of the speed of light). A supernova remnant is formed after the explosion and its boundaries are based on the shockwave from the exploding supernova and is made up of the ejected stellar material of dust and gas.

The Crab Nebula is the most popular and well known supernova remnant in the Universe In 1987, a supernova erupted in the Large Magellanic Cloud and afterwards formed the Supernova Remnant 1987A. It was the closest exploding star observed in modern times.

Image Caption: Three-dimensional turbulent mixing in a stratified burning oxygen shell which is four pressure scale heights deep. The yellow ashes of sulphur are being dredged up from the underlying orange core. The multi-scale structure of the turbulence is prominent. Entrained material is not particularly well mixed, but has features which trace the large scale advective flows in the convection zone. Also visible are smaller scale features, which are generated as the larger features become unstable, breaking apart to become part of the turbulent cascade. The white lines indicate the boundary of the computational domain.

ALMA Telescope Finds Evidence of Newly Formed Dust Made from Supernova

Artist's impression of dustfilled supernova 1987A
Credit: Alexandra Angelich (NRAO/AUI/NSF)

Researchers have captured an image of supernova 1987A with newly formed dust that was not present when the supernova was discovered. The amount of new dust comprises about 25% of the Sun's mass.

This observation gives direct evidence to support the theory of the dust making abilities of a supernova. It can also explain why young and newly formed galaxies have a dusty, dusky appearance.

When the supernova was discovered in 1987, the closest observed supernova explosion since 1604, there was only a small amount of dust observed at the time. Using the Atacama Large Millimeter/submillimeter Array (ALMA) telescope, researchers discovered the amount of dust now in the supernova has significantly increased as well as huge amounts of newly formed carbon monoxide and silicon monoxide gas.

The artists impression above shows SN 1987A's inner regions in red where huge amounts of dust were detected and imaged by ALMA. This inner region is contrasted with the outer shell (lacy white and blue circles), where the energy from the supernova is colliding with the envelope of gas ejected from the star prior to its powerful detonation.

Supernova SN 1987 was first observed in February 1987 and achieved peak brightness in May of that year. SN 1987 is around 168,000 light-years away and is located in the Large Magellanic Cloud.

Supernova Remnant at the Dragon's Head Nebula Captured

The European Southern Observatory using the FORS (FOcal Reducer and low dispersion Spectrograph) instrument captured a detailed image of NGC 2035 known as the Dragon's Head Nebula. The image shows filaments of gas and dust clouds that resulted from a supernova explosion.

A nebula is an interstellar cloud of dust, hydrogen, helium and other ionized gases.

The Dragon's Head Nebula is located in the Large Magellanic Cloud (LMC). The LMC is a galaxy 163,000 light years away and contains around 35 million stars. The LMC is smaller than the Milky Way galaxy at 14,000 light years wide compared to the Milky Way's width of 100,000 light years.

Studying the Evolution of a Supernova Through Supernova Remnant 1987A

Astronomers are intensively studying Supernova Remnant 1987A to find out more about the inner workings of stars, supernovas, and how they interact with the surroundings.

A supernova is an astronomical event where a star runs out of fuel or reaches critical mass and explodes. The explosion from a supernova can expel stellar materials at a rate of about 30,000 kilometers per second (10% of the speed of light).

After the explosion, what is left of the star is a structure called a Supernova Remnant (SNR). The boundaries of a SNR is based on the shockwave from the supernova and is made up of the ejected stellar material of dust and gas.

One of the most popular and well known supernova remnant is the Crab Nebula. Most supernova remnants are named after objects or animals they resemble. Just recently, a SNR was discovered that resembled a Florida Manatee.

In early 1987, a supernova erupted in the Large Magellanic Cloud and afterwards formed the Supernova Remnant 1987A. It was the closest exploding star observed in modern times.

Cosmic Rays Confirmed To Originate From Supernovas In Two Separate Announcements

When stars explode, the supernovas send off shock waves, which accelerate protons to cosmic-ray energies through a process known as Fermi acceleration. In this mechanism, named for Enrico Fermi who first hypothesized it, the protons gain energy from collisions with turbulent magnetic fields on either side of a shock wave. Though many details of Fermi acceleration remain unknown, new results from the Fermi Gamma-ray Space Telescope provide overwhelming evidence that the mechanism is indeed responsible for producing many of the galaxy's cosmic ray protons.
Credit: Greg Stewart, SLAC National Accelerator Laboratory

In two separate announcements (and two separate studies), the European Southern Observatory and the Kavli Institute for Particle Astrophysics and Cosmology at the Department of Energy's (DOE) SLAC National Accelerator Laboratory confirmed that cosmic rays come from exploding stars or supernovas.

Cosmic rays are high energy particles from space. These particles travel at close to the speed of light and originate from outside the Solar System. They have very high energy that they can penetrate the Earth's atmosphere and even through solid rock at the surface. Prior to the announcement, its origin and how it was formed has been a mystery.

The ESO together with the Max Planck Institute for Astronomy in Heidelberg Germany, used the VIMOS Equipment on the Very Large Telescope (VLT) to study SN 1006, a supernova first observed in the year 1006, to gather data and base their discovery of the cosmic ray mystery. Their study, An Integral View of Fast Shocks around Supernova 1006, is appearing in the 14 February 2013 issue of the journal Science.

The Kavli Institute, NASA, and Stanford University used the Large Area Telescope (LAT), which sits onboard the Fermi Gamma-ray Space Telescope to base their findings. They used the telescope to study two supernova remnants, IC 433 and W44. Both are located within the Milky Way with IC 443 5,000 light years away from Earth in the constellation Gemini, and W44 is located about 10,000 light years away, in the constellation of Aquila. Their study, Detection of the Characteristic Pion-Decay Signature in Supernova Remnants, will be appearing in the February 15 2013 issue of the journal Science.

Supernova Remnant W50 Resembles A Manatee

The National Radio Astronomy Observatory has adopted a new nickname for W50 of "The Manatee Nebula," because the likeness between it and a resting Florida Manatee is too uncanny to ignore. Left: The W50 supernova remnant in radio (green) glows against the infrared background of stars and dust (red). Right: A Florida Manatee rests underwater in Three Sisters Springs in Crystal River, Florida.
Credit: Left: NSF's Karl G. Jansky Very Large Array (VLA), NRAO/AUI/NSF, K. Golap, M. Goss; NASA’s Wide Field Survey Explorer (WISE). Right: Tracy Colson

A supernova remnant found in the constellation of Aquila has been imaged and is found to resemble a resting Florida Manatee.

When a star runs out of fuel or reaches critical mass, it explodes into a supernove. The explosion expels stellar material at a rate of about 30,000 kilometers per second (10% of the speed of light).

The structure that results from the supernova is called a Supernova Remnant (SNR). It is bounded by the shockwave from the supernova and is made up of the ejected material from the explosion.

The Crab Nebula is an example of a supernova remnant.

Some of the SNR found in the sky resemble common objects or animals such as the Owl Nebula, The Crab Nebula, or the Veil Nebula.