This map suggests that the center of the Milky Way, and the black hole in it, is 25,800 light years from Earth. This is closer than the official value of 27,700 light years adopted by the International Astronomical Union in 1985, the National Observatory of Japan said.
In addition, according to the map, our solar system is moving at 227 kilometers per second orbiting the galactic center – that’s faster than the official value of 220 kilometers per second, the statement added.
These updated values are the result of more than 15 years of observations from the Japanese radio astronomy project VERA, according to an announcement released Thursday by the National Observatory of Japan. VERA is the abbreviation for VLBI Exploration of Radio Astrometry and refers to the mission’s range of telescopes, which use very long-base interferometry to explore the three-dimensional structure of the Milky Way.
Because Earth is located inside the Milky Way, it’s difficult to step back and see what the galaxy looks like. To get around this, the project used astrometry, the precise measurement of the position and movement of objects, to understand the overall structure of the Milky Way and the place of the Earth in it.
The black hole is known as Sagittarius A * or Sgr A * and is 4.2 million times more massive than our sun. The supermassive hole and its enormous gravitational field govern the orbits of stars in the center of the Milky Way. Reinhard Genzel and Andrea Ghez won the 2020 Nobel Prize in Physics for his discovery. There are several types of black holes, and scientists believe that supermassive holes may be linked to the formation of galaxies, as they often exist at the center of massive star systems – but it’s still not clear exactly how or what shape first.
A MORE PRECISE APPROACH
In August, VERA published its first catalog, containing data for 99 celestial objects. Based on this catalog and recent observations from other groups, astronomers have constructed a position and speed map. From this map, scientists were able to calculate the center of the galaxy, the point around which everything revolves.
VERA combines data from four radio telescopes across Japan. The observatory said that, when combined, the telescopes were able to achieve a resolution that, in theory, would allow astronomers to spot a US penny placed on the surface of the Moon.
To be clear, the changes don’t mean Earth is plunging toward the black hole, the observatory said. Rather, the map identifies more precisely where the solar system has been from the start.