The Milky Way may be even larger than estimated

12 Jul. () –

The Milky Way may be larger than previously thought and have a more complex radial structure, according to a study led by Yunnan University published in Nature Astronomy.

Using data from stellar spectroscopic surveys, the researchers constructed a radial density distribution of stars from the inner to the outer regions of the Galaxy, measuring the radius of our galaxy.

The result indicates that the structure of the galactic disk in the outer disk region conforms to a classical exponential distribution, while the inner disk region remains nearly flat. This finding is distinct from the traditional assumption of a single exponential disk for the galaxy, according to Lian Jianhui, a researcher at Yunnan University. quoted by Xinhua.

19,000 LIGHT YEAR RADIUS

Lian said the study may influence the measurement of key physical properties of the galaxy. Based on past assumptions, the Galaxy’s half-light radius, within which half of its luminosity lies, was estimated to be about 10,000 light-years. The radius was extraordinarily small compared to galaxies of similar mass, and therefore the galaxy was classified as a compact galaxy.

However, based on the complex density distribution proposed in the study, the galaxy’s half-light radius is 19,000 light-years, almost in line with the radius of nearby galaxies of similar mass. This indicates that the galaxy is a typical disk galaxy in terms of size, Lian said.

Lian said the study contributes to understanding the overall structure and evolution of the galaxy.