Bacteria-Sized Microscopic Deformation of a Neutron Star Inferred From 4500 Light-Years Away - SciTechDaily

Imagine that the size of a bacterium is measured from a distance of about 4500 light-years.

This would be an incredible measurement, considering that a bacterium is so small that a microscope is required to see it, and what an enormous distance light can travel in 4500 years, given that it can round the Earth more than seven times in just one second.

But a small deformation of the size of a bacterium, that is an extra height of a few micrometers in one direction, has now been inferred for a neutron star at a distance of about 4500 light-years, from a research by Prof.

A microscopic deformation of the neutron star in the binary stellar system PSR J1023+0038 is inferred.

The extra height of the neutron star in one direction is only a few micrometres that is of the size of a bacterium, which is estimated from a distance of about 4500 light-years.

A slight asymmetry or deformation around the spin axis of such a star would cause the emission of gravitational waves continuously.

Continuous gravitational waves, for example from a slightly deformed and spinning neutron star, have so far not been detected.

The current instruments may not have the capability to detect these waves, if the deformation is too small.

However, a way to indirectly infer such waves and to measure this deformation is to estimate the contribution of the waves to the spin-down rate of the pulsar, which was not possible till now.

Using these values, and primarily a fundamental principle of physics, that is the conservation of angular momentum, Bhattacharyya has inferred continuous gravitational waves and has estimated the neutron star’s microscopic deformation.

Reference: “The permanent ellipticity of the neutron star in PSR J1023+0038” by Sudip Bhattacharyya, 18 August 2020, Monthly Notices of the Royal Astronomical Society.

August 17, 2020

August 16, 2020