Measuring neutron star squeezability

image: A neutron star begins its life as a star between about 7 and 20 times the mass of the sun. When this type of star runs out of fuel, it collapses under its own weight, crushing its core and triggering a supernova explosion. What remains is an ultra-dense sphere only about the size of a city across, but with up to twice the mass of the sun squeezed inside.

Image: 
NASA / Walt Feimer

A team of scientists used a telescope on the International Space Station to measure the size of PSR J0740+6620 (J0740, for short), the most massive known neutron star. NASA’s Neutron star Interior Composition Explorer (NICER) has captured unprecedented detail from this stellar remnant to learn more about matter in its core, which is on the threshold of collapsing into a black hole.

The NICER team will introduce their groundbreaking findings at a press conference during the 2021 APS April Meeting. NASA astronaut Christina Koch will join them to talk about how researchers use the space station as a science platform.

From pencils to pulsars

“Matter makes up everything we can see in the universe, from pencils to people to planets. In the heart of a neutron star, it’s on the verge of collapsing into a black hole,” said Cole Miller, an astronomy professor at the University of Maryland, College Park and a member of the NICER team.

“We can’t recreate those conditions on Earth, but scientists can study them from a distance by measuring the masses and sizes of neutron stars and calculating how dense they are.”

Miller will share the results from one of two groups that independently calculated the size of J0740.

Neutron star squeezability

“Our measurements of J0740 help constrain the squeezability of matter in neutron star cores, or at what density neutrons, one of the atomic building blocks, break down into smaller particles,” said Anna Watts, a professor of astrophysics at the University of Amsterdam.

Watts will share the results from the other independent team that calculated J0740’s size.

Combined with data from other neutron stars and multimessenger observations, the J0740 results herald a new age of neutron star science.

FEATURED TALKS

NICER Constraints on the Neutron Star Equation of State (E03.3, E03.4)

4:39 p.m. - 5:06 p.m. CDT, Saturday, April 17, 2021
Thomas Riley
Livestream: Access here
Abstract: http://meetings.aps.org/Meeting/APR21/Session/E03.3

5:06 p.m. - 5:33 p.m. CDT, Saturday, April 17, 2021
Cole Miller
Livestream: Access here
Abstract: http://meetings.aps.org/Meeting/APR21/Session/E03.4

PRESS CONFERENCE

Register for the press conference to be held on Zoom at 10:00 a.m. CDT, Saturday, April 17, 2021.

Speakers:

Zaven Arzoumanian (NICER Science Lead, NASA’s Goddard Space Flight Center)

Cole Miller (Professor of Astronomy, University of Maryland)

Anna Watts (Professor of Astrophysics, University of Amsterdam)

Sanjay Reddy (Professor of Physics, University of Washington)

Christina Koch (NASA Astronaut)

Media Contacts:

Claire Andreoli
Public Affairs Officer
NASA’s Goddard Space Flight Center, Greenbelt, Md.
claire.andreoli@nasa.gov
(301) 286-1940

Jeanette Kazmierczak
Science Writer
NASA’s Goddard Space Flight Center
jeanette.a.kazmierczak@nasa.gov

Credit: 
American Physical Society