LAWD 37

Hubble has used microlensing to measure the mass of a white dwarf star.

The dwarf, called LAWD 37, is a burned-out star in the centre of this NASA/ESA Hubble Space Telescope image. Though its nuclear fusion furnace has shut down, trapped heat is sizzling on the surface at roughly 100 000 degrees Celsius, causing the stellar remnant to glow fiercely.

The white dwarf has a ‘spike’ because it is so bright that the light ‘bled’ into the Hubble camera’s CCD detector. This interfered with one of the observing dates for measuring that background star’s position on the sky.

Image description

Image Description : A single bright blue star dominates the scene against a dark background with many small stars visible in the distance.