2023 Author: Bryan Walter | [email protected]. Last modified: 2023-05-21 22:24
Galaxy NGC 4565 used in the work
The Milky Way is likely continuing to grow at 500 meters per second, researchers said at European Astronomy and Space Science Week on April 3. Scientists made such a conclusion based on observations of other galaxies similar to ours.
The Milky Way has at least five main arms and contains between 200 billion and 400 billion stars. It is rather difficult to give accurate estimates of the size of our galaxy, since we cannot look at it from the outside, but astronomers assume that its diameter reaches 100 thousand light years. In addition, the disk of the Milky Way is surrounded by a halo of old stars and globular clusters. Despite the fact that most of the objects are located at a distance of less than 100,000 light years, scientists are finding objects such as Pal 4, which "flew" from the galactic center for 200 thousand light years.
There are also active star-forming regions at the outer edge of the disk, and models predict that new stars will gradually increase the size of the galaxy in which they are located. However, due to the fact that our planet is hidden inside the Milky Way, we cannot trace how its boundaries change. This problem can be partially solved by an indirect method, observing galaxies similar to ours.
To find out if the analogs of the Milky Way are getting larger over time, Cristina Martínez-Lombilla of the Canary Institute of Astrophysics, together with colleagues studied data on other galaxies obtained by the SDSS optical telescope and the GALEX and Spitzer observatories in the near infrared and UV -range. Scientists have recorded the radiation and vertical movement of stars on the outskirts of galactic disks in order to understand how long it will take for them to move from their original positions, as well as how the shape of galaxies will change. The complete list of objects analyzed by astronomers is not reported - it is known that the sample included NGC 4565 in the constellation Coma of Veronica and NGC 5907 in the constellation Draco.
Based on the observations, the research team calculated that the analogs of the Milky Way are growing at an average speed of 500 meters per second. “The Milky Way is already big enough. However, our work shows that at least the visible part of it is slowly increasing in size due to stars forming on the outskirts. This is not a fast process, but if we could fly into the future and look at the galaxy in 3 billion years, we would see that it has grown by 5 percent,”comments Martinez-Lombilla.
Astronomers have recently taken new measurements of the local arm of the Milky Way, which houses the solar system. It may be nearly twice as long as previously thought - presumably about 20,000 light-years in length.
