Astronomers discover a star so massive that its forming a tiny star around it rather than planets

A young star 40 times our Sun’s mass is forming a sibling star, not planets.

Key Takeaways

1. Astronomers discovered that massive star MM 1a is forming a smaller companion, MM 1b.
2. MM 1b emerged from a fragment of MM 1a’s disk, defying typical planet-forming patterns.
3. MM 1a is 40 times the Sun’s mass, while MM 1b weighs just half as much as the Sun.
4. This rare observation reveals a star forming from its companion’s fragmented disk.
5. The system, likely to end in a supernova within a million years, offers insights into stellar evolution.

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A Massive Star’s Unusual Formation Surprise

Astronomers have uncovered an extraordinary discovery in the formation of stars, observing a colossal young star, MM 1a, forming a smaller companion star, MM 1b, instead of planets. Using the Atacama Large Millimeter/submillimeter Array (ALMA), researchers identified MM 1b on the outskirts of MM 1a’s dense disk of dust and gas, a region traditionally associated with planet formation.

This groundbreaking finding, published in the Astrophysical Journal Letters, marks one of the first instances of a star forming within the fragmented disk of its companion. MM 1a, an infant star about 40 times the mass of the Sun, appears to have undergone a gravitational collapse, breaking its disk into fragments. One fragment had enough material to form the smaller companion star, MM 1b, which weighs just half the Sun’s mass.

The Birth of Stellar Siblings

Stars are commonly born in pairs, formed from massive clouds of dust and gas that collapse under their own gravity. However, the discovery of MM 1b challenges traditional binary star formation theories, as this smaller star was born not from an independent cloud but from the fragmented disk of its larger sibling.

The researchers analyzed the light emissions from the stars’ disks to calculate their masses, confirming MM 1b’s uniqueness. Its formation also raises the possibility of a planet-forming disk around it, adding another layer of complexity to this intriguing system.

Sadly, the stars’ fiery futures are already sealed. MM 1a, due to its immense mass, is expected to exhaust its fuel within a million years, likely ending its life in a catastrophic supernova that could obliterate the system, including any potential planets.

Despite this grim outcome, the discovery provides valuable insights into stellar formation, particularly in systems where gravitational instability plays a critical role. It highlights the universe’s surprises and serves as a reminder that there are countless stellar phenomena yet to be understood.