https://www.space.com/astronomy/stars/starbirth-shuts-down-40-000-light-years-from-the-milky-ways-core-and-astronomers-dont-know-why

According to a space.com article written by Keith Cooper on April 28th, astronomers have discovered the boundary of star formation in the Milky Way’s spiral disk. Stars form in a 40,000 light year radius. It displays a U shaped distribution of ages, with the oldest stars being in the middle and on the edges, like most other galaxies. The old stars on the edge of that radius were likely carried there via radial migration, a phenomenon where stars ride the density waves that form the Milky Way’s spiral arms out to greater distances from the galactic center. It takes a long time for stars to reach the edge so that’s why they’re the oldest. The 40,000 lightyear endpoint for star formation might have a structural cause. It’s possible that our galaxy’s central bar, measurements of the length of which vary between radii of 11,000 to 15,000 light-years, causes gas to pool out to a certain distance from the galactic center. The warp in our galaxy’s spiral disk, presumed to be caused by another dwarf galaxy, might also be cutting off star formation. Our galaxy is at least 100,000 lightyears across, and in class we learned more about its size and structure.

We discussed the structure and size of the Milky Way galaxy in a tutorial in the lecture tools workbook, on pages 163-166. This section was the Milky Way Scales section, and we learned the difference between spiral and elliptical galaxies, were shown diagrams of it to gain an understanding of its size, and we looked at the galaxy pictures in the back of the textbook and were asked to determine which ones were spiral or elliptical. We were also asked to differentiate the characteristics of each one, like common colors, amount of visible stars, shape, and the presence of arms. 

Learning about our own home galaxy was important to me because I only knew a little bit about it before the lesson. I didn’t know about different galaxy classifications like spiral galaxies vs elliptical galaxies. The Milky Way is the only confirmed galaxy with life in it, so studying it more may point us to other galaxies that might hold star systems with planets that could have life, or we could build one there.