Isaac Newton was the first to suggest that gravity could bend light, but Albert Einstein expanded on this idea with his 1915 theory of general relativity, which accurately predicted the angle at which starlight would be deflected when passing near the Sun.
Recently, Professor Oscar del Barco Novillo from the University of Murcia in Spain has developed an exact equation to calculate the gravitational bending of light (GBL) angle, accounting for the positions of both the light source and the observer at any distance from a static gravitational mass.
This development is significant because it could help astronomers precisely determine the locations of asteroids and other minor objects in the solar system. This would lead to more accurate calculations of their orbits around the Sun, making it easier to identify objects that could potentially threaten Earth.
These objects include those in the Kuiper Belt, a region beyond Neptune’s orbit filled with icy bodies like Pluto and other dwarf planets. Additionally, there is the Oort Cloud, a vast, spherical shell of icy objects that lies at the outermost edge of our solar system and is home to many long-period comets.
This research aims to more precisely determine the location of Proxima Centauri, the nearest star to Earth after the Sun. It is 4.25 light-years away and is believed to host three exoplanets. Accurately pinpointing its position would also allow for a more accurate estimation of these planets’ orbits.
Based on a geometric optics model, the study presents an exact equation for calculating the gravitational bending of light (GBL) angle caused by a massive static object, such as the Sun or planets in our solar system. This breakthrough could have broader implications, improving the precision in locating distant stars and refining the orbits of minor solar system objects like asteroids.
Professor Novillo said, “As a consequence, different branches of astronomy and astrophysics, such as celestial mechanics or stellar dynamics, might benefit from this new result.”
The new calculation could also enable more precise location measurements of distant galaxies distorted and magnified by intervening mass, such as galaxy clusters, through weak gravitational lensing. This advancement is particularly significant for astrometry, the branch of astronomy focused on accurately measuring celestial positions and movements.
Additionally, it may lead to more detailed maps of mass distribution within galaxy clusters, especially with the upcoming work of the European Space Agency’s Euclid mission.
Professor Novillo said: “The fundamental significance of our new equation is its high accuracy for the GBL angle calculation due to a static gravitational mass, compared with previous approximate equations based on the post-Newtonian formalism.”
“As a result, it might be instrumental in finding a precise location of minor celestial objects in our solar system and, consequently, a better determination of their orbits around the Sun.”
“The new research should, therefore, be important for astronomers and astrophysicists working on ultra-precise astrometry measurements, particularly in gravitational lensing studies.”
Journal Reference:
- Oscar del Barco. An accurate equation for a static massive object’s gravitational bending of light. Monthly Notices of the Royal Astronomical Society. DOI: 10.1093/mnras/stae2277