A telescope that will study neutron stars, remnants of stars between 10 and 30 times more massive than the Sun that ended their lives in supernova explosions, arrived at the International Space Station (ISS) on June 5, where it will be robotically mounted for use in several experiments.
Titled the Neutron-star Interior Composition Explorer (NICER), the telescope will study neutron stars in X-ray wavelengths, using its 56 X-ray mirrors to peer into the inner workings of these extremely dense objects as part of the Station Explorer for X-ray Timing and Navigational Technology (SEXTANT).
Neutron stars radiate energy in several wavelengths but are brightest in X-rays. They contain approximately the mass of the Sun but have diameters averaging just 12. 5 miles (20 km).
Because the precursor star’s protons and electrons are crushed during the supernova explosion, these dead stars are composed solely of neutrons.
Just a teaspoon of material from a neutron star would weigh about one billion tons on Earth.
Pulsars are an intriguing class of neutron stars that rotate extremely fast and have bright magnetic fields. They emit formidable beams in the direction opposite their spins.
However, these beams are visible to observers only when they are pointed toward Earth.
Some pulsars spin as rapidly as hundreds of times per second. The spins, or pulsings, are as predictable and accurate as atomic clocks.
Zaven Arzoumanian, a physicist and lead NICER researcher at NASA’s Goddard Space Flight Center in Maryland, believes pulsars could one day be used as tools for celestial navigation.
“The fact that we have these pulsars apparently flashing away in the sky makes them interesting as tools. You can imagine having a system of clocks, very accurate clocks, distributed all over the sky. In the same way that we use atomic clocks on GPS satellites to navigate our cars and ourselves on the surface of the Earth, we can use these clock signals from the sky, from pulsars, to navigate spacecraft anywhere in the solar system,” he explained.
Both the NICER telescope and SEXTANT software will be tested as part of a demonstration mission over the next year-and-a-half.