University of Southampton | 2015 Oct 05
Researchers from the University of Southampton have developed a new method for measuring the mass of pulsars – highly magnetised rotating neutron stars formed from the remains of massive stars after they explode into supernovae.
[img3="Still from Pulsar Animation. Image Credit: NASA"]http://www.southampton.ac.uk/assets/imp ... 0_true.jpg[/img3][hr][/hr]Until now, scientists have determined the mass of stars, planets and moons by studying their motion in relation to others nearby, using the gravitational pull between the two as the basis for their calculations. However, in the case of young pulsars, mathematicians at Southampton have now found a new way to measure their mass, even if a star exists on its own in space.
Dr Wynn Ho, of Mathematical Sciences at the University of Southampton, who led the research says: “For pulsars, we have been able to use principles of nuclear physics, rather than gravity, to work out what their mass is – an exciting breakthrough which has the potential to revolutionise the way we make this kind of calculation.”
Collaborator Dr Cristobal Espinoza of the Pontificia Universidad Catolica de Chile goes on to explain: “All previous precise measurements of pulsar masses have been made for stars that orbit another object, using the same techniques that were used to measure the mass of the Earth or Moon, or discover the first extrasolar planets. Our technique is very different and can be used for pulsars in isolation.”
Pulsars emit a rotating beam of electromagnetic radiation, which can be detected by telescopes when the beam sweeps past the Earth, like observing the beam of a lighthouse. They are renowned for their incredibly stable rate of rotation, but young pulsars occasionally experience so-called ‘glitches’, where they are found to speed up for a very brief period of time.
The prevailing theory is that these glitches arise as a rapidly spinning superfluid within the star transfers its rotational energy to the star's crust, the component that is tracked by observations. ...
Pinning down the superfluid and measuring masses using pulsar glitches - Wynn C. G. Ho et al
- Science Advances 1(9):E1500578 (02 Oct 2015) DOI: 10.1126/sciadv.1500578
arXiv.org > astro-ph > arXiv:1510.00395 > 01 Oct 2015