• 6 hours ago
Over 2 decades of Chandra X-ray Observatory views of the Crab Nebula and Cassiopeia A have been time-lapsed. The Chandra team explains here.

Credit: NASA/CXC/A. Hobart
Transcript
00:00Music
00:03Visit Chandra's beautiful universe.
00:06Crab Nebula and Cassiopeia A
00:10New movies of two of the most famous objects in the sky,
00:13the Crab Nebula and Cassiopeia A,
00:16are being released from NASA's Chandra X-ray Observatory.
00:20Each includes X-ray data collected by Chandra over about two decades.
00:24They show dramatic changes in the debris and radiation remaining
00:28after the explosion of two massive stars in our galaxy.
00:32The Crab Nebula, the result of a bright supernova explosion
00:36seen by Chinese and other astronomers in the year 1054,
00:40is 6,500 light-years from Earth.
00:43At its center is a neutron star, a super-dense star produced by the supernova.
00:48As it rotates at about 30 times per second,
00:51its beam of radiation passes over the Earth every orbit,
00:55like a cosmic lighthouse.
00:57As the young pulsar slows down,
01:00large amounts of energy are injected into its surroundings.
01:03In particular, a high-speed wind of matter and antimatter particles
01:07plows into the surrounding nebula,
01:09creating a shockwave that forms the expanding ring seen in the movie.
01:13Jets from the poles of the pulsar spew X-ray-emitting matter
01:17and antimatter particles in a direction perpendicular to the ring.
01:21Over 22 years, Chandra has taken many observations of the Crab Nebula.
01:26With this long runtime, astronomers see clear changes
01:30in both the ring and the jets in the new movie.
01:33Previous Chandra movies showed images taken from much shorter time periods,
01:37a five-month period between 2000 and 2001,
01:41and over seven months between 2010 and 2011 for another.
01:46The longer time frame highlights mesmerizing fluctuations,
01:50including whip-like variations in the X-ray jet
01:53that are only seen in this much longer movie.
01:56A new set of Chandra observations will be conducted later this year
02:01to follow changes in the jet since the last Chandra data was obtained in early 2022.
02:07The second billing in this doubleheader is just as spectacular.
02:12Cassiopeia A, or Cas A for short,
02:15is the remains of a supernova
02:17that is estimated to have exploded about 340 years ago in Earth's sky.
02:23While other Chandra movies of Cas A have previously been released,
02:27including one with data extending from 2000 to 2013,
02:31this new movie is substantially longer, featuring data from 2000 through 2019.
02:38The outer region of Cas A shows the expanding blast wave of the explosion.
02:43The blast wave is composed of shock waves
02:46similar to the sonic booms generated by a supersonic aircraft.
02:51These expanding shock waves are sites where particles are being accelerated to energies
02:56that are higher than the most powerful accelerator on Earth,
02:59the Large Hadron Collider.
03:01As the blast wave travels outwards,
03:03it encounters surrounding material and slows down,
03:06generating a second shock wave that travels backwards relative to the blast wave,
03:11analogous to a traffic jam traveling backwards from the scene of an accident on a highway.
03:17These two movies show Chandra's capabilities
03:20of documenting changes in astronomical objects over human time frames.
03:25Such movies would not be possible without Chandra's archives
03:29that serve as public repositories for the data collected
03:32over Chandra's nearly 25 years of operations.
03:47NASA Jet Propulsion Laboratory, California Institute of Technology

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