Gravitational wave astronomy is still in its infancy. Until now, this science has focused on the most energetic and recognizable sources of gravitational waves, such as catastrophic mergers of black holes and neutron stars.
But that will change as gravitational telescopes develop, allowing astronomers to explore the universe in ways that were previously impossible.
Although gravitational waves have many similarities to light waves, one clear difference is that most objects are transparent to gravitational waves. Matter can absorb, scatter, and absorb light, but gravitational waves usually pass through matter without blinking. It can be affected by the mass of the object, but cannot completely prevent entry into it.
This means that gravitational waves can be used as a tool to look inside astronomical objects, similar to how X-rays or MRIs allow us to see inside the human body.
That’s the idea behind a recent study looking at how to use gravitational waves to probe the interior of the sun, which is too hot and dense for light to penetrate. Even light produced in the sun’s core takes more than 100,000 years to reach the surface of the sun.
Our only knowledge of the Sun’s interior comes from helioscience, where astronomers study the vibrations on the sun’s surface caused by sound waves inside the sun.
In this new study, the team looks at how to use gravitational waves from rapidly spinning neutron stars to study the sun. While a perfectly smoothly rotating object does not produce gravitational waves, it does produce objects that rotate asymmetrically.
Neutron stars can have perturbations or spikes caused by internal heat or magnetic fields. If such a neutron star is spinning rapidly, it produces a steady stream of gravitational waves that are too weak to be detected by current telescopes, but the next generation of gravitational observatories should be able to detect them. this.
Because neutron stars are common in space, some of them are positioned so that in our view the sun passes in front of them. Of the more than 3,000 known pulsars, about 500 are good candidates for gravitational wave sources. The team used the properties of these three pulsars as a starting point.
Since the sun is transparent to gravitational waves, the only effect the sun has on it is through its gravitational mass. As waves pass through the sun, they partially reverse their own gravity. The size of the lens depends on the mass of the sun and its distribution. The team found that at the appropriate scales, gravitational wave observations were able to measure the Sun’s density profile with an accuracy of 3 sigma.
It is possible that the three known pulsars are only a small fraction of the sources of gravitational waves that pass behind the sun. Most neutron stars have spin directions that don’t point their radio flashes in our direction, but they can still be used as gravitational probes.
Source: ScienceAlert
Source: Arabic RT
