Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

First view of a newborn millisecond pulsar?

14.02.2002


Artist’s impression of millisecond pulsar and companion


The globular cluster NGC 6397


Combining Hubble Space Telescope images with radio observations has revealed a highly unusual system consisting of a fast spinning pulsar and a bloated red companion star. The existence of the system is something of a mystery - the best explanation so far is that we have our first view of a millisecond pulsar just after it has been `spun up` by its red companion star.

Although more than 90 specimens of the exotic species of fast-spinning `millisecond pulsars` are known today, no observations have yet been made to back up the theory of how they reached this state. A series of observations of the millisecond pulsar PSR J1740-5340 (spinning at 274 times per second) and its companion star from the ESA/NASA Hubble Space Telescope and the Parkes radio telescope seem to show the final stage of the pulsar acceleration process for the first time.
The generally favoured `recycling scenario` describing the creation of millisecond pulsars proposes that an old, slowly rotating neutron star begins to absorb matter from its elderly companion star, typically a red giant. The matter hits the surface of the neutron star and transfers energy to make it rotate faster. The process ends when the pulsar has been revitalised and is rotating at hundreds of times per second (hence a millisecond pulsar), and its companion almost emptied of matter and turned into a white dwarf.


A team of scientists from Bologna Astronomical Observatory conducted a series of Hubble observations of the pulsar-companion system in the globular cluster NGC 6397. The observations show that the millisecond pulsar`s companion is not the expected white dwarf, but a bloated red star, whose radius is about 100 times greater than that of a white dwarf and at least five times greater than a normal star of similar mass! This unique couple orbit around each other in 1.35 days.

The observations also indicate the abnormal presence of large amounts of gas in the system. This gas is released from the bloated companion star and soon will be swept away by the recently accelerated pulsar. Once the pulsar has been spun up it can no longer absorb gas from the companion.

Lead astronomer Francesco Ferraro explains: "We have certainly discovered a very unusual pair. A system consisting of a millisecond pulsar and a star that is not a white dwarf has never been seen before. Our favoured theory is that we are seeing the system before the bloated red star has been `emptied` of gas and turned into a white dwarf. If this compelling hypothesis is wrong then the companion star could be a normal star in the globular cluster that has been captured by the pulsar by chance. Maybe it has expelled the white dwarf that we normally find in such systems."

At last astronomers have observations to back the theory of millisecond pulsar births, and the discovery opens a new window on the evolution of millisecond pulsars.

Erica Rolfe | alphagalileo
Further information:
http://www.esa.int

More articles from Physics and Astronomy:

nachricht Optical Nanoscope Allows Imaging of Quantum Dots
23.01.2018 | Universität Basel

nachricht Two dimensional circuit with magnetic quasi-particles
22.01.2018 | Technische Universität Kaiserslautern

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: Optical Nanoscope Allows Imaging of Quantum Dots

Physicists have developed a technique based on optical microscopy that can be used to create images of atoms on the nanoscale. In particular, the new method allows the imaging of quantum dots in a semiconductor chip. Together with colleagues from the University of Bochum, scientists from the University of Basel’s Department of Physics and the Swiss Nanoscience Institute reported the findings in the journal Nature Photonics.

Microscopes allow us to see structures that are otherwise invisible to the human eye. However, conventional optical microscopes cannot be used to image...

Im Focus: Artificial agent designs quantum experiments

On the way to an intelligent laboratory, physicists from Innsbruck and Vienna present an artificial agent that autonomously designs quantum experiments. In initial experiments, the system has independently (re)discovered experimental techniques that are nowadays standard in modern quantum optical laboratories. This shows how machines could play a more creative role in research in the future.

We carry smartphones in our pockets, the streets are dotted with semi-autonomous cars, but in the research laboratory experiments are still being designed by...

Im Focus: Scientists decipher key principle behind reaction of metalloenzymes

So-called pre-distorted states accelerate photochemical reactions too

What enables electrons to be transferred swiftly, for example during photosynthesis? An interdisciplinary team of researchers has worked out the details of how...

Im Focus: The first precise measurement of a single molecule's effective charge

For the first time, scientists have precisely measured the effective electrical charge of a single molecule in solution. This fundamental insight of an SNSF Professor could also pave the way for future medical diagnostics.

Electrical charge is one of the key properties that allows molecules to interact. Life itself depends on this phenomenon: many biological processes involve...

Im Focus: Paradigm shift in Paris: Encouraging an holistic view of laser machining

At the JEC World Composite Show in Paris in March 2018, the Fraunhofer Institute for Laser Technology ILT will be focusing on the latest trends and innovations in laser machining of composites. Among other things, researchers at the booth shared with the Aachen Center for Integrative Lightweight Production (AZL) will demonstrate how lasers can be used for joining, structuring, cutting and drilling composite materials.

No other industry has attracted as much public attention to composite materials as the automotive industry, which along with the aerospace industry is a driver...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

10th International Symposium: “Advanced Battery Power – Kraftwerk Batterie” Münster, 10-11 April 2018

08.01.2018 | Event News

See, understand and experience the work of the future

11.12.2017 | Event News

Innovative strategies to tackle parasitic worms

08.12.2017 | Event News

 
Latest News

Researchers reveal how microbes cope in phosphorus-deficient tropical soil

23.01.2018 | Earth Sciences

Opening the cavity floodgates

23.01.2018 | Life Sciences

Siberian scientists suggested a new method for synthesizing a promising magnetic material

23.01.2018 | Materials Sciences

VideoLinks Science & Research
Overview of more VideoLinks >>>