Groundbreaking Discovery: Planet-forming Disk Detected around Star in Distant Galaxy
Astronomers discover a young star in the Large Magellanic Cloud with a planetary disk, indicating the potential for planet formation Exciting evidence of dynamic activity in a neighboring galaxy
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Astronomers have made history by catching a glimpse of a young star located outside of the Milky Way galaxy. This star is surrounded by a thick disk, potentially indicating the formation of planets.
Astronomers have discovered a massive star known as HH 1177, along with its rotating disk, in the Large Magellanic Cloud, a nearby dwarf galaxy located 160,000 light-years away. This groundbreaking find has the potential to enhance our understanding of star and planet formation.
As a new star forms, it collects matter from its surroundings, leading to the accumulation of gas and dust in a flat disk around the star, known as an accretion disk, due to the influence of strong gravitational forces. The spinning disk then transports the matter onto the star, causing it to grow in size. The more massive the star becomes, the stronger its gravitational field, which attracts even more gas and dust into the disk.
This is the initial visualization of Sgr A*, the supermassive black hole located at the core of our galaxy, but with a black background added to accommodate wider screens. It represents the first direct optical proof of the existence of this black hole. This remarkable image was captured by the Event Horizon Telescope (EHT), an array that connected eight pre-existing radio observatories around the world to create a single "Earth-sized" virtual telescope. The telescope derives its name from the event horizon, the boundary of the black hole beyond which no light can escape. While the event horizon itself cannot be observed as it does not emit light, the glowing gas swirling around the black hole displays a distinctive signature: a dark central area (referred to as a shadow) encompassed by a bright ring-like structure. The new perspective captures light that has been bent by the immense gravitational pull of the black hole, which is four million times more massive than our Sun. The image of the Sgr A* black hole is a composite of various images extracted from EHT Collaboration's 2017 observations. In addition to other facilities, the EHT network of radio observatories that facilitated this image includes the Atacama Large Millimeter/submillimeter Array (ALMA) and the Atacama Pathfinder EXperiment (APEX) located in the Atacama Desert in Chile, and co-owned and operated by ESO as a partner representing its member states in Europe.
European Southern Observatory/EHT Collaboration
Our galaxys black hole spins fast and drags space-time with it, scientists say
HH 1177, a massive star, lives a fast-paced life and has a much shorter lifespan compared to stars like our sun. As a result, it is difficult to observe the early stages of such massive stars in our galaxy due to their hidden nature behind dusty material. However, the material from which stars are formed within the Large Magellanic Cloud differs from that of the Milky Way.
HH 1177 is located in a stellar nursery called N180, which has a lower abundance of dust and metal. The star is not obstructed by gas and dust, allowing for a clear view from a distance.
Lead study author Dr. Anna McLeod, an associate professor of physics at Durham University in the United Kingdom, expressed her excitement at discovering evidence of a rotating structure in the ALMA data. She described it as a special moment, emphasizing the significance of seeing direct evidence for the formation of stars and planets in another galaxy for the first time.
Astronomers detected a star approximately 15 times the mass of our sun using the Atacama Large Millimeter/submillimeter Array of telescopes in Chile, known as ALMA. The findings were published in the journal Nature on Wednesday.
The ALMA observations were conducted as a follow-up to a prior discovery made using the European Southern Observatory's Very Large Telescope. The telescope's Multi Unit Spectroscopic Explorer (MUSE) instrument captured a stream of material emanating from the young star. HH 1177 was located deep within a gas cloud within the galaxy.
"We have identified a jet being emitted from this young, large star, and its existence indicates continuing disc accretion," stated McLeod.
The extragalactic disk discovery was a result of collaboration among various observatories. Using the MUSE instrument of the Very Large Telescope, the star and its jets were initially detected (on the left and center). Subsequent observations from ALMA (on the right) unveiled the presence of a rotating disk surrounding the star.
ESO/ALMA (ESO/NAOJ/NRAO)/A. McLeod et al.
To discern whether a disk was present around the star, the team needed to measure how quickly dense gas moved around the star.
As matter is pulled towards a developing star, it doesn't simply fall onto the celestial body. Instead, it flattens out and begins to orbit the star, forming a disk-shaped structure. The rotation of the disk varies, with the center spinning faster than the outer edges. This difference in speed can assist astronomers in identifying the presence of a disk around a star.
By regularly tracing the link between two neighboring planets as they orbit, a unique pattern is formed for each pair. The six planets in the HD110067 system collectively create a captivating geometric pattern as a result of their resonance-chain.
Astronomers have found a pattern of six exoplanets with rhythmic light emissions. Dr. Jonathan Henshaw, a research fellow at Liverpool John Moores University in the UK, explained that the frequency of light changes based on the speed of the emitting gas, comparing it to the change in pitch of an ambulance siren as it approaches and passes.
The ALMA observations were able to make precise measurements of the rotation of the disk.
Accretion disks are not exclusive to young stars. Supermassive black holes also have thin, hot disks of matter swirling around them that they feed on.
McLeod noted that in this era of rapid technological advancements in astronomical facilities, it is very exciting to be able to study how stars form at such incredible distances and in a different galaxy.
