An artists conception of the Milky Way.
Using data from the Gaia satellite telescope, a team headed by Lund University researchers in Sweden found that large parts of the Milky Ways outer disk vibrate. The ripples are brought on by a dwarf galaxy that went by our galaxy hundreds of millions of years back and is now noticeable in the constellation Sagittarius.
The Milky Way, our cosmic home, contains between 100 and 400 billion stars. The galaxy is believed to have actually formed 13.6 billion years back, originating from a rotating cloud of gas composed of hydrogen and helium. The gas then accumulated over billions of years in a turning disk, where stars like our sun were created.
The research study group provides their findings on the stars in the outer areas of the galactic disk in a new research study that was recently published in the journal Monthly Notices of the Royal Astronomical Society.
The galaxy is believed to have formed 13.6 billion years ago, originating from a rotating cloud of gas made up of hydrogen and helium. The gas then collected over billions of years in a turning disk, where stars like our sun were developed.
The information exposed that a strange ripple was triggering stars all around the galaxy to oscillate at various speeds..
” We can see that these stars wobble and go up and down at various speeds. When the dwarf galaxy Sagittarius passed the Milky Way, it created wave motions in our galaxy, a bit like when a stone is dropped into a pond”, Paul McMillan, the astronomy scientist at Lund Observatory who led the research study, explains.
The research study group was able to check out a far larger area of the Milky Ways disk than was formerly possible thanks to data from the European space telescope Gaia. The scientists have started to put together a complex puzzle by determining the strength of the ripples in various parts of the disc, supplying hints about Sagittarius history and orbit around our home galaxy.
” At the minute, Sagittarius is gradually being torn apart, but 1-2 billion years ago it was considerably larger, most likely around 20 percent of the mass of the Milky Ways disk,” says Paul McMillan.
The scientists were surprised by how much of the Milky Way they could study utilizing the information from Gaia. To date, the telescope, which has actually been in operation since 2013, has actually determined the movement across the sky of around 2 billion stars and the motion towards or away from us of 33 million.
” With this new discovery, we can study the Milky Way in the very same method that geologists draw conclusions about the structure of the Earth from the seismic waves that travel through it. This kind of “stellar seismology” will teach us a lot about our home galaxy and its advancement,” Paul McMillan concludes.
Referral: “The disturbed external Milky Way disc” by Paul J McMillan, Jonathan Petersson, Thor Tepper-Garcia, Joss Bland-Hawthorn, Teresa Antoja, Laurent Chemin, Francesca Figueras, Shourya Khanna, Georges Kordopatis, Pau Ramos, Merce Romero-Gómez and George Seabroke, 15 September 2022, Monthly Notices of the Royal Astronomical Society.DOI: 10.1093/ mnras/stac2571.
