Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


Astronomers discover first Thorne-Zytkow object, a bizarre type of hybrid star


In a discovery decades in the making, scientists have detected the first of a "theoretical" class of stars first proposed in 1975 by physicist Kip Thorne and astronomer Anna Żytkow.

Thorne-Żytkow objects (TŻOs) are hybrids of red supergiant and neutron stars that superficially resemble normal red supergiants, such as Betelguese in the constellation Orion. They differ, however, in their distinct chemical signatures that result from unique activity in their stellar interiors.

TŻOs are thought to be formed by the interaction of two massive stars―a red supergiant and a neutron star formed during a supernova explosion―in a close binary system. While the exact mechanism is uncertain, the most commonly held theory suggests that, during the evolutionary interaction of the two stars, the much more massive red supergiant essentially swallows the neutron star, which spirals into the core of the red supergiant.

While normal red supergiants derive their energy from nuclear fusion in their cores, TŻOs are powered by the unusual activity of the absorbed neutron stars in their cores. The discovery of this TŻO thus provides evidence of a model of stellar interiors previously undetected by astronomers.

Project leader Emily Levesque of the University of Colorado Boulder, who earlier this year was awarded the American Astronomical Society's Annie Jump Cannon Award, said, "Studying these objects is exciting because it represents a completely new model of how stellar interiors can work. In these interiors we also have a new way of producing heavy elements in our universe. You've heard that everything is made of 'star stuff'—inside these stars we might now have a new way to make some of it."

The study, accepted for publication in the Monthly Notices of the Royal Astronomical Society Letters, is co-authored by Philip Massey, of Lowell Observatory in Flagstaff, Arizona; Anna Żytkow of the University of Cambridge in the U.K.; and Nidia Morrell of the Carnegie Observatories in La Serena, Chile.

The astronomers made their discovery with the 6.5-meter Magellan Clay telescope on Las Campanas, in Chile. They examined the spectrum of light emitted from apparent red supergiants, which tells them what elements are present. When the spectrum of one particular star—HV 2112 in the Small Magellanic Cloud―was first displayed, the observers were quite surprised by some of the unusual features. Morrell explained, "I don't know what this is, but I know that I like it!"

When Levesque and her colleagues took a close look at the subtle lines in the spectrum they found that it contained excess rubidium, lithium and molybdenum. Past research has shown that normal stellar processes can create each of these elements. But high abundances of all three of these at the temperatures typical of red supergiants is a unique signature of TŻOs.

"I am extremely happy that observational confirmation of our theoretical prediction has started to emerge," Żytkow said. "Since Kip Thorne and I proposed our models of stars with neutron cores, people were not able to disprove our work. If theory is sound, experimental confirmation shows up sooner or later. So it was a matter of identification of a promising group of stars, getting telescope time and proceeding with the project."

The team is careful to point out that HV 2112 displays some chemical characteristics that don't quite match theoretical models. Massey points out, "We could, of course, be wrong. There are some minor inconsistencies between some of the details of what we found and what theory predicts. But the theoretical predictions are quite old, and there have been a lot of improvements in the theory since then. Hopefully our discovery will spur additional work on the theoretical side now."

Emily Levesque | Eurek Alert!
Further information:

More articles from Physics and Astronomy:

nachricht Move over, lasers: Scientists can now create holograms from neutrons, too
21.10.2016 | National Institute of Standards and Technology (NIST)

nachricht Finding the lightest superdeformed triaxial atomic nucleus
20.10.2016 | The Henryk Niewodniczanski Institute of Nuclear Physics Polish Academy of Sciences

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: New 3-D wiring technique brings scalable quantum computers closer to reality

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...

Im Focus: Scientists develop a semiconductor nanocomposite material that moves in response to light

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...

Im Focus: Diamonds aren't forever: Sandia, Harvard team create first quantum computer bridge

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...

Im Focus: New Products - Highlights of COMPAMED 2016

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...

Im Focus: Ultra-thin ferroelectric material for next-generation electronics

'Ferroelectric' materials can switch between different states of electrical polarization in response to an external electric field. This flexibility means they show promise for many applications, for example in electronic devices and computer memory. Current ferroelectric materials are highly valued for their thermal and chemical stability and rapid electro-mechanical responses, but creating a material that is scalable down to the tiny sizes needed for technologies like silicon-based semiconductors (Si-based CMOS) has proven challenging.

Now, Hiroshi Funakubo and co-workers at the Tokyo Institute of Technology, in collaboration with researchers across Japan, have conducted experiments to...

All Focus news of the innovation-report >>>



Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

Agricultural Trade Developments and Potentials in Central Asia and the South Caucasus

14.10.2016 | Event News

World Health Summit – Day Three: A Call to Action

12.10.2016 | Event News

Latest News

Resolving the mystery of preeclampsia

21.10.2016 | Health and Medicine

Stanford researchers create new special-purpose computer that may someday save us billions

21.10.2016 | Information Technology

From ancient fossils to future cars

21.10.2016 | Materials Sciences

More VideoLinks >>>