Nasa discovers x-ray pulsar with fastest orbit ever recorded – clarksville, tn online gas utility worker

Hot spots form when a neutron star’s intense gravitational field pulls material away from a stellar companion — in J17062, from the white dwarf — where it collects into an accretion disk. Matter in the disk spirals down, eventually making its way onto the surface. Neutron stars have strong magnetic fields, so the material lands on the surface of the star unevenly, traveling along the magnetic field to the magnetic poles where it creates hot spots.

Some pulsars rotate over 700 times per second, comparable to the blades of a kitchen blender. X-ray fluctuations from pulsars are so predictable that NICER’s companion experiment, the Station Explorer for X-ray Timing and Navigation Technology (SEXTANT), has already shown they can serve as beacons for autonomous navigation by future spacecraft.

Over time, material from the donor star builds up on the surface of the neutron star. Once the pressure of this layer builds up to the point where its atoms fuse, a runaway thermonuclear reaction occurs, releasing the energy equivalent of 100 15-megaton bombs exploding over every square centimeter, explained Strohmayer. X-rays from such outbursts can also be captured by NICER, although one has yet to be seen from J17062.

The researchers were able to determine that J17062’s stars revolve around each other in a circular orbit, which is common for AMXPs. The white dwarf donor star is a “lightweight,” only around 1.5 percent of our Sun’s mass. The pulsar is much heavier, around 1.4 solar masses, which means the stars orbit a point around 1,900 miles (3,000 km) from the pulsar.

“The distance between us and the pulsar is not constant,” Strohmayer said. “It’s varying by this orbital motion. When the pulsar is closer, the X-ray emission takes a little less time to reach us than when it’s further away. This time delay is small, only about 8 milliseconds for J17062’s orbit, but it’s well within the capabilities of a sensitive pulsar machine like NICER.”

NICER’s mission is to provide high-precision measurements to further study the physics and behavior of neutron stars. Other first-round results from the instrument have provided details about one object’s thermonuclear bursts and explored what happens to the accretion disk during these events.

Neutron stars turn out to be truly unique nuclear physics laboratories, from a terrestrial standpoint,” said Zaven Arzoumanian, a Goddard astrophysicist and lead scientist for NICER. “We can’t recreate the conditions on neutron stars anywhere within our solar system. One of NICER’s key objectives is to study subatomic physics that isn’t accessible anywhere else.”

NICER is an Astrophysics Mission of Opportunity within NASA’s Explorer program, which provides frequent flight opportunities for world-class scientific investigations from space utilizing innovative, streamlined, and efficient management approaches within the heliophysics and astrophysics science areas.

Topics Black Hole, Greenbelt MD, International Space Station, ISS, Jeanette Kazmierczak, NASA, NASA’s Explorer Program, NASA’s Goddard Space Flight Center, National Aeronautics and Space Administration, Neutron Star, NICER, Orbit, Pulsar, Stars, Supernova, White Dwarf