Using the Five-hundred Aperture Spherical Telescope (FAST), astronomers from China and Australia have recently discovered five new pulsars.
About Five-hundred Aperture Spherical Telescope (FAST)
- It is a radio telescope in China's Guizhou Province.
- It is the world's largest and most sensitive radio telescope, with a receiving area equivalent to 30 football fields.
- It measures 500 meters in diameter.
- Scientific Goals:
- Detect neutral hydrogen at the edge of the universe; reconstruct the images of the early universe;
- Discover pulsars, establish a pulsar timing array, and participate in pulsar navigation and gravitational wave detection in the future;
- Join the International Very-Long-Baseline Interferometry Network to obtain hyperfine structures of celestial bodies;
- Perform high resolution radio spectral survey. Detect weak space signals;
- Participate in the search for extraterrestrial intelligence.
- FAST uses a data system developed at ICRAR (International Center for Radio Astronomy) in Perth, Australia, and at ESO (European Southern Observatory) to manage the huge amounts of data it generates.
What are Pulsars?
- Pulsars are rapidly rotating neutron stars that blast out pulses of radiation at regular intervals ranging from seconds to milliseconds.
- Pulsars have strong magnetic fields that funnel particles along their magnetic poles, accelerating them to relativistic speeds, which produce two powerful beams of light, one from each pole.
- Because the poles of the magnetic field aren't aligned with the axis of spin of the pulsar, the beams of particles and the light they produce are swept around as the pulsar rotates.
- The periodicity of pulsars is caused by these beams of light crossing the line of sight on Earth, with the pulsar appearing to 'switch off' at points when the light is facing away from us.
- The time between these pulses is the 'period' of the pulsar.
What is a neutron star?
- When a massive star explodes as a supernova at the end of its life, its core can collapse into a tiny and superdense object with not much more than our sun’s mass.
- These small, incredibly dense cores of exploded stars are neutron stars.
Q1) What are gravitational waves?
Gravitational waves are ripples in the fabric of spacetime caused by the acceleration of massive obje+cts, such as the collision of black holes or the explosion of supernovae. These waves were predicted by Albert Einstein in his theory of general relativity, which he published in 1915. According to this theory, massive objects, like planets and stars, create gravitational fields that warp the fabric of spacetime around them.