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
NASA's SDO sees partial eclipse in space
29.05.2017 | NASA/Goddard Space Flight Center
Strathclyde-led research develops world's highest gain high-power laser amplifier
29.05.2017 | University of Strathclyde
The world's highest gain high power laser amplifier - by many orders of magnitude - has been developed in research led at the University of Strathclyde.
The researchers demonstrated the feasibility of using plasma to amplify short laser pulses of picojoule-level energy up to 100 millijoules, which is a 'gain'...
Staphylococcus aureus is a feared pathogen (MRSA, multi-resistant S. aureus) due to frequent resistances against many antibiotics, especially in hospital infections. Researchers at the Paul-Ehrlich-Institut have identified immunological processes that prevent a successful immune response directed against the pathogenic agent. The delivery of bacterial proteins with RNA adjuvant or messenger RNA (mRNA) into immune cells allows the re-direction of the immune response towards an active defense against S. aureus. This could be of significant importance for the development of an effective vaccine. PLOS Pathogens has published these research results online on 25 May 2017.
Staphylococcus aureus (S. aureus) is a bacterium that colonizes by far more than half of the skin and the mucosa of adults, usually without causing infections....
Physicists from the University of Würzburg are capable of generating identical looking single light particles at the push of a button. Two new studies now demonstrate the potential this method holds.
The quantum computer has fuelled the imagination of scientists for decades: It is based on fundamentally different phenomena than a conventional computer....
An international team of physicists has monitored the scattering behaviour of electrons in a non-conducting material in real-time. Their insights could be beneficial for radiotherapy.
We can refer to electrons in non-conducting materials as ‘sluggish’. Typically, they remain fixed in a location, deep inside an atomic composite. It is hence...
Two-dimensional magnetic structures are regarded as a promising material for new types of data storage, since the magnetic properties of individual molecular building blocks can be investigated and modified. For the first time, researchers have now produced a wafer-thin ferrimagnet, in which molecules with different magnetic centers arrange themselves on a gold surface to form a checkerboard pattern. Scientists at the Swiss Nanoscience Institute at the University of Basel and the Paul Scherrer Institute published their findings in the journal Nature Communications.
Ferrimagnets are composed of two centers which are magnetized at different strengths and point in opposing directions. Two-dimensional, quasi-flat ferrimagnets...
24.05.2017 | Event News
23.05.2017 | Event News
22.05.2017 | Event News
29.05.2017 | Life Sciences
29.05.2017 | Physics and Astronomy
29.05.2017 | Statistics