Through the use of a monster telescope attached to a modified Boeing 747 jet, astronomers have discovered the dust of an ancient supernova near the center of the Milky Way.
This finding is unique in that it was thought the turbulent nature of an expanding supernova explosion should destroy this dust, but its presence provides a fascinating insight as to why many galaxies appear to be dust-rich, adding critical detail to star and planet-formation theories.
“Dust itself is very important because it’s the stuff that forms stars and planets, like the sun and Earth, respectively, so to know where it comes from is an important question,” said lead author Ryan Lau, a postdoctoral associate for astronomy at Cornell University in Ithaca, NY. “Our work strongly reinforces the theory that supernovae are producing the dust seen in galaxies of the early universe.”
It has been long theorized that a key production mechanism for heavy elements in our universe are created by supernovae — the explosions generated as massive stars run out of fuel and die. These detonations are powerful enough to form dust rich in the materials that go on to form further generations of stars and the planets that orbit around them.
But one of the biggest conundrums in galactic evolution is why galaxies are so rich in dust when the supernovae themselves are thought, in theory, to destroy the majority of the dust they create in the turbulent aftermath.
So, using an instrument called FORCAST (the Faint Object Infrared Camera Telescope) on board SOFIA (the Stratospheric Observatory for Infrared Astronomy), a joint project between NASA, German Aerospace Center and the Universities Space Research Association, the astronomers have gained an invaluable insight to one particular supernova remnant near the center of our galaxy.
SOFIA is an airborne observatory that is able to fly above the majority of the Earth’s atmosphere at an altitude of 13.7 kilometers (45,000 ft). The 747-mounted, 2.5 meter diameter infrared telescope occupies a valuable “sweet spot” in infrared astronomy. Ground-based telescopes cannot see the long infrared wavelengths as the atmosphere blocks space emissions from reaching the ground. Also, currently, no space-based instrument can cover the wavelengths that SOFIA can.
So when the observatory zoomed in on Sagittarius A East, a 10,000-year-old supernova remnant near the galactic center, SOFIA had a first look at the infrared light generated by this surprisingly abundant supernova remnant dust.
“There have been no direct observations of any dust surviving the environment of the supernova remnant … until now, and that’s why our observations of an ‘old’ supernova are so important,” said Lau.
Lau’s team’s work has been published in the March 19 edition of Science Express.