Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


‘Stellar cannibalism’ is key to formation of overweight stars

Researchers have discovered that the mysterious overweight stars known as blue stragglers are the result of ‘stellar cannibalism’ where plasma is gradually pulled from one star to another to form a massive, unusually hot star that appears younger than it is.

The process takes place in binary stars – star systems consisting of two stars orbiting around their common centre of mass. This helps to resolve a long standing mystery in stellar evolution.

The research, which is part funded by the UK’s Science and Technology Facilities Council (STFC) and carried out by scientists at Southampton University and the McMaster University in Canada, is published in the journal Nature on Thursday 15 January.

Blue stragglers are found throughout the Universe in globular clusters - collections of about 100, 000 stars, tightly bound by gravity. According to conventional theories, the massive blue stragglers found in these clusters should have died long ago because all stars in a cluster are born at the same time and should therefore be at a similar phase. These massive rogue stars, however, appear to be much younger than the other stars and are found in virtually every observed cluster.

Dr Christian Knigge from Southampton University, who led the study, comments: “The origin of blue stragglers has been a long-standing mystery. The only thing that was clear is that at least two stars must be involved in the creation of every single blue straggler, because isolated stars this massive simply should not exist in these clusters.”

Professor Alison Sills from the McMaster University explains further: “We’ve known of these stellar anomalies for 55 years now. Over time two main theories have emerged: that blue stragglers were created through collisions with other stars; or that one star in a binary system was ‘reborn’ by pulling matter off its companion.”

The researchers looked at blue stragglers in 56 globular clusters. They found that the total number of blue stragglers in a given cluster did not correlate with predicted collision rate – dispelling the theory that blue stragglers are created through collisions with other stars.

They did, however, discover a connection between the total mass contained in the core of the globular cluster and the number of blue stragglers observed within in. Since more massive cores also contain more binary stars, they were able to infer a relationship between blue stragglers and binaries in globular clusters. They also showed that this conclusion is supported by preliminary observations that directly measured the abundance of binary stars in cluster cores. All of this points to "stellar cannibalism" as the primary mechanism for blue straggler formation.

Dr Knigge says: “This is the strongest and most direct evidence to date that most blue stragglers, even those found in the cluster cores, are the offspring of two binary stars. In our future work we will want to determine whether the binary parents of blue stragglers evolve mostly in isolation, or whether dynamical encounters with other stars in the clusters are required somewhere along the line in order to explain our results.”

This discovery comes as the world celebrates the International Year of Astronomy in 2009.

Julia Short | alfa
Further information:

More articles from Physics and Astronomy:

nachricht OU-led team discovers rare, newborn tri-star system using ALMA
27.10.2016 | University of Oklahoma

nachricht First results of NSTX-U research operations
26.10.2016 | DOE/Princeton Plasma Physics Laboratory

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: Etching Microstructures with Lasers

Ultrafast lasers have introduced new possibilities in engraving ultrafine structures, and scientists are now also investigating how to use them to etch microstructures into thin glass. There are possible applications in analytics (lab on a chip) and especially in electronics and the consumer sector, where great interest has been shown.

This new method was born of a surprising phenomenon: irradiating glass in a particular way with an ultrafast laser has the effect of making the glass up to a...

Im Focus: Light-driven atomic rotations excite magnetic waves

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...

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...

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

How nanoscience will improve our health and lives in the coming years

27.10.2016 | Materials Sciences

OU-led team discovers rare, newborn tri-star system using ALMA

27.10.2016 | Physics and Astronomy

'Neighbor maps' reveal the genome's 3-D shape

27.10.2016 | Life Sciences

More VideoLinks >>>