The Magellenic Clouds Stay Connected By A String Of Stars

Universe Today ^ | 02/08/2017 | Evan Gough

[BenLurkin]

They move so slowly that a human lifetime is a tiny blip compared to them. This makes their orbit essentially unobservable.

But astronomers were able to find the next best thing: the often predicted but never observed stellar stream, or bridge of stars, stretching between the two clouds.

A star stream forms when a satellite galaxy feels the gravitational pull of another body. In this case, the gravitational pull of the LMC allowed individual stars to leave the SMC and be pulled toward the LMC. The stars don’t leave at once, they leave individually over time, forming a stream, or bridge, between the two bodies. This action leaves a luminous tracing of their path over time.

The astronomers behind this study think that the bridge actually has two components: stars stripped from the SMC by the LMC, and stars stripped from the LMC by the Milky Way. This bridge of RR Lyrae stars helps them understand the history of the interactions between all three bodies. A Bridge of Stars… and Gas

The most recent interaction between the Clouds was about 200 million years ago. At that time, the Clouds passed close by each other. This action formed not one, but two bridges: one of stars and one of gas. By measuring the offset between the star bridge and the gas bridge, they hope to narrow down the density of the corona of gas surrounding the Milky Way.

Mystery #2: The Milky Way’s Corona

The Galactic Corona is made up of ionised gas at very low density. This makes it very difficult to observe. But astronomers have been scrutinizing it intensely because they think the corona might harbor most of the missing baryonic matter.

[minnesota_bound]

More info here: “A String Of Pearls”
https://www.youtube.com/watch?v=aQUljW_s50I

[BenLurkin]

tasty!