Discovered for the first time a disk around a star in another galaxy

As technology advances, the Universe reveals itself and shows us how unaware we are of it. In a remarkable discovery, astronomers have found a disk surrounding a young star in the Large Magellanic Cloud, a neighboring galaxy to ours.

And are there planets like ours in another galaxy?
This is the first time that a record of this type, identical to those that form planets in our Milky Wayis found outside our Galaxy.
The new observations reveal a young star of great mass growing and accreting matter from the environment that surrounds it, thus giving rise to a rotating disk.  This detection was made with the help of ALMA (Atacama Large Millimeter/submillimeter Array) in Chile, of which ESO is a partner.

When I first saw evidence of a rotating structure in the ALMA data, I couldn't believe we had detected the first extragalactic accretion disk, it really was a special moment.
We know that disks are vital for the formation of stars and planets in our Galaxy and, for the first time, we now have direct evidence of the same phenomenon occurring in another galaxy.

Said Anna McLeod, associate professor at the University of Durham, in the United Kingdom, and lead author of the study published in the journal Nature.
This study follows observations with the MUSE (Multi Unit Spectroscopic Explorer) instrument on ESO's VLT (Very Large Telescope), which detected a jet launched by a forming star — the system was named HH 1177 — inside a cloud of gas in the Large Magellanic Cloud.

We discovered a jet being launched by this young, massive star, which is a sign of an accretion disk in formation.

McLeod explained.
However, to have irrefutable proof that this disk was indeed present, the team had to measure the movement of dense gas around the star.
According to what is said, when matter is attracted to a growing star, it does not fall directly onto it;  instead, it flattens into a disk that revolves around the star.  Closer to the center, the disk rotates faster, and this difference in speed is the clue that signals to astronomers the existence of an accretion disk.

With the combined capabilities of ESO VLT It's from ALMA, a disk was observed around a young, massive star in another galaxy.  On the left we have observations made with the instrument MUSE, coupled to the VLT, and which show the progenitor cloud, LHA 120-N 180B, in which the system, called HH 1177, was initially observed.  The center image shows the accompanying jets.  The upper part of the jet moves slightly towards us and is therefore blueshifted;  the lower part of the jet is moving away from us and so we see it as redshifted.  On the right, observations carried out with ALMA reveal the disk rotating around the star, with parts moving closer and further away from us.  Credit: ESO/ALMA (ESO/NAOJ/NRAO)/A.  McLeod et al.


The frequency of the radiation varies depending on the speed at which the gas that emits this radiation moves towards us or in the opposite direction.  This is exactly the same phenomenon that occurs when the tone of an ambulance siren changes as it passes us and the frequency of the sound changes from higher to lower.

Explains Jonathan Henshaw, researcher at Liverpool John Moores University, in the United Kingdom, and co-author of this study.
The detailed frequency measurements that ALMA is capable of allowed the authors to distinguish the characteristic rotation of a disk, confirming the first detection of a disk around a young extragalactic star.
Massive stars, such as the one observed here, form much more quickly and have much shorter lives than low-mass stars, such as our Sun. In our Galaxy, these massive stars are notoriously They are difficult to observe and are often obscured by the dusty material from which they formed as a disk is forming around them.
However, in the Large Magellanic Cloud, a galaxy 160,000 light-years away from Earth, the material from which new stars are forming is fundamentally different from that in the Milky Way.
Thanks to the smaller amount of dust present there, HH 1177 is no longer wrapped in its natal cocoon, therefore offering astronomers an unobstructed, albeit distant, view of the formation of stars and planets.

We are in an era of rapid technological advances when it comes to astronomical facilities.  Being able to study how stars form at such incredible distances and in a different galaxy is really exciting.

McLeod concludes.