A star is a large ball of hot gas and in its incredibly hot interior hydrogen atoms combine to form helium, which subsequently forms carbon, other heavier elements and finally iron. When all the atoms in the centre have turned to iron the fuel is depleted and the star dies. When very large and massive stars, that are at least about eight times as massive as our sun, die, they explode as supernovae.
Enormous swollen stars
But some massive stars become red supergiant stars first, which is an intermediate phase where, after the fuel in the centre is used up, energy is still produced in shells surrounding the now dead core. In this phase, the star swells up to an enormous size, approximately 1500 times larger than the sun, and emits as much light as a hundred thousand suns. But there has been doubt over whether red supergiants explode as supernovae.
Using images from the Hubble Space Telescope and the Gemini Observatory, Justyn R. Maund, astrophysicist at the Dark Cosmology Centre, Niels Bohr Institute, University of Copenhagen and astrophysicist Stephen J. Smartt, Queens University Belfast, have observed two stars that exploded as supernovae. By analysing archival images of the same section of the sky from long before the explosions, the researchers could see which stars might have gone supernova. But picking out individual stars in the distant universe is difficult, and pinpointing exactly which star it was that exploded is a huge challenge.
Stars became supernovae
A supernova is visible in the sky for some time after its explosion before its giant dust- and gas clouds are blown clear. The researchers can then observe the region around the position of the supernova several years after the supernova explosion and can then see exactly which star has disappeared.
For one of the supernovae, SN1993J (which exploded in 1993) they found that a red supergiant no longer exists, but that its neighboring star remained. In addition, they found that the red supergiant that was postulated to have caused the supernova SN2003gd has also disappeared. This simple but very time intensive method, establishes that it was these two red supergiant stars that produced the supernovae 2003J and 2003gd, and confirms that red supergiant stars create type II supernovae.
Maund and Smartt have found the missing link between red supergiant stars and their supernovae, giving astronomers a greater understanding of how massive stars die. Stellar death is a process crucial for understanding the origin of the chemical elements in the Universe, a precursor necessary ultimately to the formation of planets and life.
Gertie Skaarup | EurekAlert!
Light-driven atomic rotations excite magnetic waves
24.10.2016 | Max-Planck-Institut für Struktur und Dynamik der Materie
Move over, lasers: Scientists can now create holograms from neutrons, too
21.10.2016 | National Institute of Standards and Technology (NIST)
Terahertz excitation of selected crystal vibrations leads to an effective magnetic field that drives coherent spin motion
Controlling functional properties by light is one of the grand goals in modern condensed matter physics and materials science. A new study now demonstrates how...
Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.
"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...
In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.
A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...
By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.
"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...
COMPAMED has become the leading international marketplace for suppliers of medical manufacturing. The trade fair, which takes place every November and is co-located to MEDICA in Dusseldorf, has been steadily growing over the past years and shows that medical technology remains a rapidly growing market.
In 2016, the joint pavilion by the IVAM Microtechnology Network, the Product Market “High-tech for Medical Devices”, will be located in Hall 8a again and will...
14.10.2016 | Event News
14.10.2016 | Event News
12.10.2016 | Event News
24.10.2016 | Earth Sciences
24.10.2016 | Life Sciences
24.10.2016 | Physics and Astronomy