Looking at the waves in the fabric of space-time, scientists will soon be able to detect "strange stars" - objects formed from a material that is radically different from the particles that make up ordinary matter.
The protons and neutrons that make up the nuclei of atoms are made up of several basic particles, known as quarks. There are only six types or “flavors” of quarks: lower, upper, strange, charming, charming and true. Each proton or neutron consists of three quarks: a proton consists of one lower and two upper quarks, each neutron consists of one upper and two lower.
In theory, matter can also be formed from other flavors of quarks. Since 1970, scientists have suggested that particles of "strange matter" can be formed from an equal number of top, bottom and strange quarks. In principle, strange matter must be heavier and more stable than ordinary matter, and may even be able to turn into ordinary matter. However, laboratory experiments have not yet created a single particle of strange matter, so its existence remains uncertain.
One of the places where strange matter can naturally form is the nucleus of neutron stars - the remnants of stars that died as a result of a catastrophic explosion known as a supernova. Neutron stars are usually small with a diameter of about 12 miles (19 kilometers) or so, but so dense that they weigh as much as the Sun. For example, a piece of a neutron star, the size of a piece of sugar, can weigh 100 million tons. Under the extraordinary power of this extreme weight, some of the lower and upper quarks that make up neutron stars can transform into strange quarks, which leads to the formation of strange stars from strange matter.
A strange star, which at times ejects particles of strange matter, can quickly convert a neutron star rotating in a binary star system into a strange star. Studies show that a neutron star, which takes a seed of strange matter from a strange star, can transform itself into a strange star in just 1 millisecond.
Now, researchers suggest that they can detect strange stars by examining the gravitational waves of stars — an invisible ripple in spacetime that Albert Einstein first suggested as part of his theory of the general theory of relativity.
Gravitational waves are emitted due to mass acceleration. Really large gravitational waves are formed due to very large masses, such as a pair of neutron stars, merging with each other.
A pair of strange stars emits gravitational waves, which are different from those that emit a pair of “normal” neutron stars, as strange stars should be more compact, the researchers say. For example, a neutron star with a mass equal to one-fifth of the Sun should be no more than 18 miles (30 km) in diameter, while a strange star of the same mass should be no more than 6 miles (10 km) in diameter.
Researchers suggest that events associated with strange stars may explain two short gamma spikes - giant explosions lasting less than 2 seconds, seen in deep space in 2005 and 2007. The laser-interferometric gravitational-wave observatory (eng. Laser Interferometer Gravitational-Wave Observator, abbr. LIGO) could not detect the gravitational waves from these events, called GRB 051103 and GRB 070201. The neutron star fusion is an explanation of short gamma bursts, but LIGO was supposed to detect the gravitational waves from these fusions. However, as the researchers say, if strange stars were involved in both of these events, LIGO could not detect such gravitational waves.
However, future research will be able to detect these strange star phenomena. Through the use of an additional gravitational-wave observatory laser interferometer (ALIGO), whose first launch was scheduled for 2015, the researchers expect to detect about 0, 13 neutron star fusions with strange ones per year (that is, one such fusion every eight years). Thanks to Einstein's telescope, which is currently being developed in the European Union, scientists ultimately expect to detect about 700 such events a year.
