Stars Are Not Made from a Single Mold: The Gaia Discovery ⚡ экспресс
The Initial Mass Function (IMF) describes how many stars of different masses are born. Astronomers used to consider it a universal 'constant' across the entire Universe. However, Gaia data on open clusters allowed us to reliably test this for the first time: the IMF turned out not to be the same—it varies from cluster to cluster, reflecting the conditions in their parent clouds and the evolution of the Galaxy. This agrees with long-standing theoretical predictions and reminds us that even in space, 'recipes' depend on the environment.
For a long time, the Universe was seen as a strict baker: it was thought that in every corner, stars were mixed from the same recipe — for each giant star, there were roughly the same number of dwarfs, no matter where they were born. This ratio was called the initial mass function, but checking it was tricky: to count all the buns in a faraway bakery, you need to see even the tiniest ones.
The Gaia satellite, armed with ultra-precise brightness measurements, peered into hundreds of open clusters — batches of star-formed ‘bakes’. It turned out that different galactic regions follow their own recipes: where gas and dust were denser and hydrogen was hotter, giants emerged several times more often. The Universe is more like a network of bakeries with distinct traditions than a single assembly line.
This simple fact changes a lot. For instance, estimates of the number of habitable planets and the distribution of dark matter in galaxies were based on the old assumptions. Now it’s clear: even the basic ingredients of the cosmos are mixed without a template, and astronomers have to rewrite their cookbooks.
🎯 The Sun is a middleweight, but the vast majority of stars in the Milky Way are dim red dwarfs, which live hundreds of times longer and shine hundreds of times fainter.