The Ultimate Black-Hole Sleuth –NuSTAR Launches Today: Peering into the Event Horizon of Supermassive Black Holes




NuSTAR, the Nuclear Spectroscopic Telescope Array, a black hole hunter with ultra sharp X-ray eyes, will be launched from Kwajalein Atoll in the central Pacific Ocean today, no earlier than 9:00 a.m. PDT (12:00 p.m. EDT) June 13. Coverage and commentary will be broadcast online beginning 90 minutes before launch at

NuSTAR's mission will be to explore the inner workings of black holes, the mechanisms driving some of the most awesome explosions in the cosmos, and to record processes heating the sun's corona to more than 1 million degrees using X-rays – a form a light substantially more energetic than visible light and capable of piercing enshrouding clouds of cosmic dust.

Black holes, supernovae and other cosmic sources can give off light across the whole electromagnetic spectrum, from low-energy infrared waves to high-energy gamma radiation. But much of that light is invisible even to the Hubble Space Telescope and the ChandraX-rayObservatory, which are focused on the infrared, visible, ultraviolet and low-energyX-rayportions of the spectrum. Much of the lower-energy light gets absorbed by gas and dust floating through space, essentially blocking these objects from view.

The $170 million X-ray observatory will allow scientists to observe activity around black holes and other sources of X-rays with greater sharpness and clarity than any telescopes currently available, using a 33-foot-long mast that extends out from the spacecraft in space. Two sets of optics on the end of the mast will deliver the X-rays they pick up to detectors on the spacecraft in a tightly focused group.



NuSTAR will not only will be able to create images 10 times sharper than those from other orbiting X-ray observatories, but it will also be able to see X-ray sources 100 times fainter, including the event horizons of supermassive black holes, where matter is compressed and heated, eventually reaching the point where it emits radiation as X-rays. Existing X-ray telescopes can detect emissions from fairly close to the event horizon. But NuSTAR is designed to detect more-energetic X-rays, in effect giving it a window on conditions even closer to the event horizon.

NuSTAR will also zero in on two supernova remnants: Cassiopeia A and SN 1987A. In Cass A's case, the type of star that exploded is unknown. But supernova 1987A involved a star some 20 times the sun's mass. When a star at least 10 times the sun's mass explodes, the object that remains after a supernova is a neutron star – essentially a solid core of neutrons with as much mass as the sun but packed into an object the size of Manhattan. But if a far more massive star goes supernova, the result is a black hole – an object so dense and with gravity so intense that not even light travels fast enough to escape it.

The Chandra X-ray Observatory has detected a neutron star at the heart of Cass A, but it can't detect key features of the expanding remnants of the original star that can help answer key questions scientists have regarding supernovae explosions. Scientists have not yet located anything at the core of SN 1987A (image below), but some experts is that a neutron star could be shrouded in dust, making it impossible to see at visible wavelengths.

Image at the top of the page is a computer simulation of superheated plasma swirling around the black hole at the center of our galaxy.



The Daily Galaxy Via

Image credit: Scott Noble/RIT

"The Galaxy" in Your Inbox, Free, Daily