Gravitational Waves: Ripples In Space-Time
Gravitational waves are invisible ripples in the fabric of space-time. They are caused by some of the most violent and energetic events in the universe.
These include colliding black holes, collapsing stellar cores, merging neutron stars or white dwarf stars, the wobble of neutron stars that are not perfect spheres and possibly even the remnants of gravitational radiation created by the birth of the universe.
In this video, Dr. Padi Boyd explains gravitational waves and how important Hubble is to exploring the mysteries of the universe.
2
views
NASA | Massive Black hole Shreds Passing Stars
Description
NASA | Massive Black Hole Shreds Passing Star
NASA Goddard
17K
Likes
6,242,521
Views
2015
Oct 21
This artist’s rendering illustrates new findings about a star shredded by a black hole. When a star wanders too close to a black hole, intense tidal forces rip the star apart. In these events, called “tidal disruptions,” some of the stellar debris is flung outward at high speed while the rest falls toward the black hole. This causes a distinct X-ray flare that can last for a few years. NASA’s Chandra X-ray Observatory, Swift Gamma-ray Burst Explorer, and ESA/NASA’s XMM-Newton collected different pieces of this astronomical puzzle in a tidal disruption event called ASASSN-14li, which was found in an optical search by the All-Sky Automated Survey for Supernovae (ASAS-SN) in November 2014. The event occurred near a supermassive black hole estimated to weigh a few million times the mass of the sun in the center of PGC 043234, a galaxy that lies about 290 million light-years away. Astronomers hope to find more events like ASASSN-14li to test theoretical models about how black holes affect their environments.
During the tidal disruption event, filaments containing much of the star's mass fall toward the black hole. Eventually these gaseous filaments merge into a smooth, hot disk glowing brightly in X-rays. As the disk forms, its central region heats up tremendously, which drives a flow of material, called a wind, away from the disk.
8
views
