With Hubble, astronomers measured the mass of a single, isolated white dwarf – which is the surviving core of a burned-out star.
The white dwarf, called LAWD 37, is 56% the mass of our Sun.
Astronomers were able to determine this using “gravitational microlensing” – when the gravity of a foreground object warps the light coming from an object behind it.
The light from a background star was slightly deflected by the gravitational warping of space by LAWD 37. As the white dwarf passed in front of the background star, microlensing caused the star to appear temporarily offset from its actual position on the sky.
These Hubble observations took place over the course of many years, and since the light from the background star was so faint, the main challenge for astronomers was extracting its image from the glare of LAWD 37, which is 400 times brighter than the background star. Only Hubble can make these kinds of high-contrast observations in visible light.
#nasa #hubble #news #space #stars #science #astronomy #universe #cosmos #telescope