Chandra’s X-ray Eyes Behold Catastrophe

To mark the 15th anniversary of NASA’s Chandra X-ray Observatory, four newly processed images of supernova remnants illustrate Chandra’s ability to explore high-energy processes in the cosmos. See end of article for detailed explanations of each. Click to enlarge. NASA/CXC/SAO

15 years ago to the day, NASA’s Chandra X-ray Observatory opened its eyes to the high-energy universe. It was launched aboard the space shuttle Columbia and entered a long elliptical orbit that takes it more than a third of the distance to the moon before returning to its closest approach to Earth of 9,942 miles. This specially tailored path keeps it above the Van Allen radiation belts – which would interfere with its X-ray vision – more than 85% of the time.

Chandra’s long elliptical orbit around the Earth keeps it away from the Van Allen belts and allows the telescope to study an object up to 55 hours without interference. NASA

Chandra, named for Indian-American astrophysicist Subrahmanyan Chandrasekhar who did groundbreaking work on white dwarf stars, is specially designed to detect X-rays emitted by hot and energetic objects in the universe. What we feel as heat – infrared light – is low-energy radiation. Planets, comets and asteroids warmed by the sun emit infrared as surely as our own bodies do.

Radio waves, some infrared and visible light penetrate the atmosphere and make it to the ground. Shorter wavelength light from energetic UV to gamma rays are stopped by the atmosphere. A good thing.

As we move to light of shorter wavelengths, energy content rises. Visible light is more energetic than infrared, UV light more so (it can give us a painful sunburn) and X-rays very much more so. To spew X-rays, something very powerful must be happening in space like a supernova explosion or matter heated to incandescence as it disappears down a black hole.

Earth’s atmosphere acts to filter out dangerous much of the more energetic particles and light waves careening around the cosmos, the reason Chandra had to be pitched into the vacuum of space to use its X-ray specs.

Chandra has observed objects ranging from the closest planets and comets to the most distant known quasars. It has imaged the remains of exploded stars, or supernova remnants, observed the region around the supermassive black hole at the center of the Milky Way, and discovered black holes across the universe.

To celebrate the anniversary, NASA released  four newly processed pictures of supernova remnants, the dusty, gassy leftovers of stars blown to smithereens. Let’s take a look at each in turn:

Chandra view of the Crab Nebula expansion in just 7 months

* Crab Nebula: At its center is a city-sized, extremely compact, rapidly rotating neutron star left after the original sun went supernova in 1054 A.D. Also called a pulsar, the star spews zillions of high-speed particles that plow into the expanding debris field to create a ghostly X-ray nebula.

* G292.0+1.8:  One of only three supernova remnants in the Milky Way known to contain large amounts of oxygen. These oxygen-rich supernovas are of great interest to astronomers because they are one of the primary sources of elements heavier than hydrogen and helium that are necessary to form planets and people. The image shows a rapidly expanding debris field that contains, along with oxygen (yellow and orange), other elements such as magnesium (green) and silicon and sulfur (blue) that were forged in the star before it exploded.

* Tycho’s remnant: The supernova that created the remnant was first noticed by Danish astronomer Tycho Brahe in 1572 as a brand new star in the constellation Cassiopeia. The supersonic expansion of the exploded star produced a shock wave moving outward into the surrounding interstellar gas, and another, reverse shock wave moving back into the expanding stellar debris. Heated to millions of degrees, the gas and debris produce copious X-rays.

* 3C58: 3C58 is the remnant of a supernova observed in the year 1181 AD by Chinese and Japanese astronomers. It contains a rapidly spinning neutron star surrounded by a thick ring of X-ray emission. The pulsar also has produced jets of X-rays blasting away from it to both the left and right, and extending trillions of miles. These jets are responsible for creating the elaborate web of loops and swirls.

As a kid, we used to joke about wishing we had X-ray vision. Now we really do.

4 Responses

  1. Norman Sanker

    Hey Bob,
    Great stuff from Chandra. Incredible image and video of the Crab. Tycho’s Remnant looks like early autumn trees from above. Where’s our supernova?! Watch us get one in our lifetime but southern hemisphere. Saw Comet Jacques Wednesday morning through a lucky window of quasi-clear skies in mid-monsoon: just a classic dim star that wouldn’t focus. Thanks for all the good work. Norman

    1. astrobob

      Hi Norman,
      Nice description of the Tycho’s remnant – bizarre colors and texture for sure. What instrument did you use to see the comet?

      1. Norman Sanker

        I started with an 80mm reflector but couldn’t find the comet so I switched to 9X35 binoculars and thought I was seeing something which the 80mm confirmed. This morning was almost clear so I pulled out the C-8. Jacques is one of those fractal comets that kind of look the same at all scales. There may have been a hint of a delta or fan shape amid the general blob–not for sure. Much nicer look with the clearer sky and bigger scope. Bright enough for binoculars but so small it’s hard to catch. Wednesday morning it was close to a brightish double which helped me find it again this AM. Light pollution has stolen my view to the north and west so I had to wait for Jacques to show his face in the east. I’m east of Tucson with the Rincon Mts. east of me so not much development out that way. Still marvel at that odd time late last year with 4 or 5 comets in the morning sky. Any idea why Heavens Above is so far off on their comet magnitudes? They’re listing Jacques at 12.

        1. astrobob

          Great detailed report Norman – thanks! Someone else asked about the Heavens Above discrepancy too. I e-mailed Chris Peat who runs the site and he was aware of the problem with his source (which I forget right now) that didn’t update. He said he was going to use a different source for better estimates but maybe he’s not gotten around to it yet.

Comments are closed.