Most detailed ever 3D map of Milky Way shows ‘warped’ shape

This sort of info feeds my febrile brain. This is what I cribbed from The Guardian.

“The most detailed three-dimensional map yet of the Milky Way has been revealed, showing that our galaxy is not a flat disc but has a “warped” shape like a fascinator hat or a vinyl record that has been left in the sun. “The stars 60,000 light years away from the Milky Way’s centre are as far as 4,500 light years above or below the galactic plane – this is a big percentage,” said Dr Dorota Skowron of the University of Warsaw, first author of the latest research.

Milky Way

Milky Way

Both the new study and an earlier one published in February, which found a similar shape, are based on the distribution across the galaxy of stars known as Cepheids – bodies whose brightness varies in a regular cycle over time. This phenomenon of dimming and brightening is the key to creating the maps. While a star might be fainter because it is further away, it could also be because it is less luminous. For Cepheids, the maximum brightness of the star is related to the length of time the cycle of brightening and dimming takes, with brighter Cepheids having longer cycles. By comparing this intrinsic brightness with how bright the star appears to be, researchers can work out how far away a Cepheid is.

The new study, published in the journal Science, encompasses data from more than 2,400 Cepheids, allowing the team to build the most detailed three-dimensional map yet of the Milky Way.

Shape of the Milky Way

Shape of the Milky Way

As with the previous work, the new study shows the Cepheids disproportionately lie on one side of the warped galaxy, forming an arc-shaped spread.

The Polish team also found younger Cepheids lie nearer the centre of the Milky Way, while older Cepheids are further out. A computer simulation revealed there would need to have been star-forming events 64m, 113m and 175m years ago to produce the distribution of Cepheids seen today.

Going to sleep tonight will be much easier now I’ve learned that!

Leave a Reply

Your email address will not be published. Required fields are marked *