After 40 years of searching, astronomers have discovered a star made of exceptionally unusual material for the first time.

In the Universe, there are a wide variety of stars. Some possess very unusual properties, but among them are those considered the most extraordinary. They are referred to as strange quark stars, and so far, no one has ever observed them, even though they are theoretically believed to exist. Now, astronomers think they have, for the first time, detected the birth of such a star. The research has been published on the arXiv preprint server, reports Phys.

Strange Quark Stars

According to theory, strange quark stars should exist in the Universe. These are highly compact objects that are smaller than a typical neutron star, which has a diameter of about 20 km. While neutron stars, which have a very large mass in a small volume, are among the densest objects in the Universe and consist of neutrons (the particles that make up the nucleus of an atom), strange quark stars are even denser, as their neutrons break down into quarks. But that’s not all. While a neutron is made up of up and down quarks, in strange quark stars, these quarks are transformed into a rare type of quark – the strange quark – under the influence of gravity. This is why these hypothetical stars are called strange quark stars.

According to existing theories, strange quark stars consist of strange matter, which is a mixture of up, down, and strange quarks. It is believed that this matter may be more stable than that found in neutron stars, where gravity prevents the separation of neutrons into quarks. Neutron stars form after massive stars explode as supernovae, causing their cores to collapse under their own gravity.

The Birth of a Star Made of Strange Matter

Theories suggest that strange quark stars should be extremely rare in the Universe. However, there is currently no evidence that they exist at all. Nonetheless, the authors of the new study believe they have obtained such evidence for the first time.

Astronomers studied the gamma-ray burst GRB 240529A, which scientists believe indicates the birth of a strange quark star. Gamma-ray bursts, powerful emissions of energy and radiation, are thought to occur as a result of the formation of stellar-mass black holes (which occur similarly to neutron stars) or due to the creation of a magnetar.

This type of neutron star, magnetars possess the strongest magnetic fields in the Universe. There are specific conditions under which a neutron star can transform into a magnetar.

Scientists believe that magnetars can collapse under their own gravity into denser and more compact objects, which may be strange quark stars. This process would result in a gamma-ray emission, and the authors of the study believe that GRB 240529A occurred during the birth of a strange quark star. Various aspects of the gamma-ray burst suggest the stages of transformation from a neutron star to a magnetar, and then to a strange quark star, which subsequently slows its rotation. Neutron stars rotate very rapidly.

Astronomers state that their data supports the theory of the birth of a strange quark star. However, additional evidence is necessary to confirm the theory regarding the existence of unusual stars made of strange matter, which emerged nearly 40 years ago.