Monthly Notices of the Royal Astronomical Society

[upbeat electronic music] Astronomers have discovered a group of 20 stars deep inside the Milky Way which may once have been part of a different galaxy.

The findings, reported in the Monthly Notices of the Royal Astronomical Society, show how galaxies like our Milky Way grow and evolve by merging with or cannibalizing other galaxies.

Astronomers are able to identify the stellar remnants of other galaxies within the Milky Way because of their proper motion through space, that is the eccentricities of their galactic orbits, or by their chemical composition, both of which are often very different from homegrown stars in the Milky Way.

This newly identified group of stars are thought to have originally formed together in a dwarf galaxy, which the authors have now named Loki, which must have merged with the Milky Way during its early evolution.

And the author for this is Giada Casali-Atel from the Australian National University.

And this was submitted to MNRAS.

And so yeah, as I said, stellar ages are really hard to measure, but they are really, really useful, especially for fields like galactic archaeology.

But yeah, so unlike properties such as temperature or the distance, you can't really observe the age directly, you have to infer it.

I'm talking about a scientific claim made in a peer-reviewed journal.

The paper shown here appeared in the 15th ever volume of the monthly notices of the Royal Astronomical Society.

That's the oldest major astronomy journal still in active use.

And it was authored by Captain, yes, I said Captain, William Stephen Jacob, who was the director of the Madras Observatory in Chennai, India.