A new map of the Milky Way by Japanese space experts has brought Earth 2,000 light-years closer to the supermassive black hole at the center of our galaxy.
This map has suggested that the center of the Milky Way, and the black hole sitting there, are 25,800 light years from Earth. This is closer than the official value of 27,700 light-years assumed by the International Astronomical Union in 1985, the National Observatory of Japan said.
What’s more, according to the map, our solar system travels at 227 kilometers per second as it revolves around the galactic center – this is faster than the official value of 220 kilometers per second, the release added.
These updated values are the result of more than 15 years of observations by the Japanese radio astronomy project VERA, according to an announcement released Thursday by the National Observatory of Japan. VERA is short for VLBI Exploration or Radio Astrometry and refers to the mission’s array of telescopes that use Very Long Baseline Interferometry to investigate the three-dimensional structure of the Milky Way.
Since the Earth is in the Milky Way, it is difficult to step back and see what the Milky Way looks like. To get around this, the project used astrometry, the accurate measurement of the position and movement of objects, to understand the overall structure of the Milky Way and Earth’s place 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 massive gravitational field control the orbits of stars in the center of the Milky Way. Reinhard Genzel and Andrea Ghez have won the Nobel Prize in Physics in 2020 for their discovery. There are different types of black holes, and scientists think the supermassive ones may be related to galaxy formation, as they often occur in the center of massive galaxies – but it’s still not clear exactly how, or which first.
MORE ACCURATE APPROACH
In August, VERA published its first catalog with data for 99 celestial objects. Based on this catalog and recent observations by other groups, astronomers have constructed a position and speed map. From this map the 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 would theoretically allow the astronomers to see a US cent 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 shows more precisely where the solar system has been all along.