May 16, Kathmandu – NASA’s upcoming powerful space telescope, the ‘Nancy Grace Roman,’ is expected to unlock the mysteries of millions of invisible neutron stars hidden within our Milky Way galaxy. According to a new study published in the journal Astronomy and Astrophysics, this telescope will not only identify these objects through gravitational effects but will also be capable of measuring their masses.
Neutron stars are incredibly dense remnants left behind after massive stars explode in supernovae. Although roughly the size of a small city, their mass exceeds that of the Sun.
Most neutron stars exist alone and do not emit light, which has made them undetectable with current powerful telescopes. So far, only a few thousand neutron stars have been discovered, while scientists estimate that there could be over 100 million such stars in our galaxy. The Roman Telescope will detect neutron stars indirectly through a technique called gravitational microlensing. When a neutron star passes in front of a distant star, its gravity bends and brightens the background star’s light.
According to lead author Jofija Kazmarik, the Roman Telescope will measure changes in the star’s brightness (photometry) along with subtle shifts in its position (astrometry). Because neutron stars are extremely dense, the gravitational signals they produce are very strong, enabling scientists to accurately determine the mass of these invisible objects.
This mission will also help unravel why neutron stars move through space at such high speeds—hundreds of miles per second. These velocities result from the “kick” they receive during the supernova explosion. By studying the mass distribution and velocity of isolated neutron stars, the Roman Telescope will provide new insights into the life cycles of stars, including their formation and destruction.
Managed by NASA’s Goddard Space Flight Center, the telescope is expected to begin transmitting data soon after launch, with significant discoveries anticipated within just a few months. Additionally, this mission will help differentiate between neutron stars and black holes.
