A new map of the galaxy has revealed that our planet is not where it is supposed to be, as it is moving 7 km / s faster and is 2000 light years closer to the supermassive black hole at the center of our galaxy (known as Sagittarius A * or Sgr A *, which is 4.2 million times more massive than our sun ); much closer to the galactic center.
Does this mean that we are headed for the black hole?
No way; No need to worry. These changes are the result of a better model of the Milky Way based on new observational data, including a catalog of objects observed over more than 15 years by the Japanese radio astronomy project called VERA ( VLBI Exploration of Radio Astrometry ). This project began mapping three-dimensional velocity and space structures in the Milky Way using a technique known as interferometry to combine data from radio telescopes scattered across the Japanese archipelago in order to achieve the same resolution as a 2,300 km diameter telescope would have. The resulting precision is incredible. Hence these new, much more specific data.
A map with greater precision
Because Earth is located inside the Milky Way, it is difficult to step back and see what the galaxy is like. Thus, based on the VERA Catalog of Astrometry and recent observations by other groups, astronomers constructed a map of position and velocity and calculated the center of the galaxy, the point around which everything rotates.
By pinpointing the location and velocity of around 99 specific points in our galaxy (the first VERA catalog), the model concluded that the supermassive black hole Sagittarius A, at the center of our galaxy, is 25,800 light years from Earth. , almost 2,000 light years closer than we previously thought.
They were also able to calculate that the Earth is moving faster than we thought. The oldest model showed that the Earth travels at 220 km / s as it orbits the galactic center. But the new model suggests that Earth has become seven km / s faster and is traveling at 227 km / s as it orbits the galactic center.
Distances are important
Identifying more precisely where the Earth has been all this time is relevant because it helps us determine with greater certainty the intrinsic brightness of objects. For example, it happened to us with the case of the star Betelgeuse, which turned out to be much closer to us than the first measurements suggested (hence we conclude that it was neither as big nor as bright as we initially thought).
VERA now hopes to observe more objects, particularly those near the central supermassive black hole, to better characterize the structure and motion of the Milky Way. And, as part of these efforts, VERA will participate in EAVN (East Asia VLBI Network) made up of radio telescopes located in Japan, South Korea and China. By increasing the number of telescopes and the maximum separation between them, they will achieve even greater precision.
Referencia: The First VERA Astrometry Catalog, Publications of the Astronomical Society of Japan (2020). DOI: 10.1093/pasj/psaa018
