A stamp printed in Jersey shows Albert Einstein (1879-1955), Einstein's Theory of General Relativity. Photo: Olga Popova

Albert Einstein set the tone for 20th century discovery when his hypothesis that gravity’s curvature of space would bend light, like an enormous magnifying glass, around massive objects was proven correct during the total solar eclipse of 1919.

But Einstein wrote in the journal Science in 1936 that such observations would not be possible with other stars, which are too impossibly distant to accurate observe.

On that point, at least, Einstein was wrong. A new study in Science this week, 81 years after Einstein’s piece, shows that an international team of scientists observed the same microlensing phenomenon in a white dwarf star that passed closely in front of another star.

Because of displacement of the light emitted, the scientists from the Space Telescope Science Institute, Penn State and other institutions were actually able to determine the mass of the white dwarf named Stein 2051 B, they report in the journal.

“As Stein 2051 B passed closely in front of a background star, the background star’s position was deflected,” they write. “Measurement of this deflection at multiple epochs allowed us to determine the mass of Stein 2051 B – the sixth-nearest white dwarf to the Sun… This mass determination provides confirmation of the physics of degenerate matter and lends support to white dwarf evolutionary theory.”

Stein 2051 B was observed on eight separate dates from October 2013 through October 2015. The minute observations determined that the mass of the white dwarf is about two-thirds that of our sun.

Although the “Einstein ring” of brightening and bending were not observable because of the distance, the scientists instead looked at what was asymmetrical about the light emitted.

Terry Oswalt of Embry-Riddle Aeronautical University wrote a perspective piece in the journal that puts the discovery in context.

“The ring and its brightening were too small to be measured, but its asymmetry caused the distant star to appear off-center from its true position,” said Oswalt. “This part of Einstein’s prediction is called ‘astrometric lensing’ and (this team) was the first to observe it in a star other than the sun.”

Einstein’s Theory of General Relativity continues to inform humankind’s observations of the universe. Early last year, a team of international astrophysicists reported their confirmation of the existence of gravitational waves – the ripple in space-time which were created by the collision of two far-off black holes. Just last month, astronomers reported the first human observation of the formation of a black hole.