Several research groups have already confirmed the theory that there are 2 black holes in the center of the distant galaxy OJ 287. Photo: NASA/JPL–Caltech/R. Hurt (IPAC) and M. Mugrauer (AIU Jena)
Until now, there is no region of the universe as monstrous as a supermassive black hole at the center of a galaxy, much less when, sometimes, its powerful jets of particles, called quasars. An international team of astronomers, using NASA’s TESS space telescope, has set its sights on the star cluster OJ 287where two of them (in a binary system) rotate emitting bursts of matter.
The largest of these supermassive black holes contains a mass of 18.35 billion suns, while the smallest reaches the mass of 100 million suns. Furthermore, when the latter surpasses the nearby domains of the most massive, a flare brighter than that of a billion stars is produced.
NASA observes that two supermassive black holes shoot jets of energy at the same time
International astronomical research teams have validated observations from the University of Turku, Finland, about the activity of two supermassive black holes in the center of the galaxy OJ 287, in the constellation Cancer, 4 billion light years from Earth. . A recent study confirms that a satellite scan in 2021 has revealed, for the first time, the characteristics of the smaller black hole of the pair.
In 2021, NASA’s TESS satellite focused its attention on the galaxy OJ 287, known to host a supermassive black hole. Originally designed to detect exoplanets, TESS has discovered more than 410 of them. However, their mission was diverted towards the study of black holes to confirm a theory long held by Finnish astronomers.
This discovery was based on the identification of a sudden burst of brightness, a phenomenon predicted by researcher Pauli Pihajoki of the University of Turku as early as 2014. According to his doctoral thesis, the event was anticipated to occur towards the end of 2021, which caused great expectations in the scientific community.
When the smallest black hole crashes into the disk, it produces a flare brighter than 1 trillion stars. Photo: NASA/JPL-Caltech
NASA on the trail of the binary system of supermassive black holes
On November 12, 2021, NASA’s TESS space telescope captured the expected flash, which lasted approximately 12 hours. This fleeting event revealed the presence of the smaller black hole by monitoring its brightness and the gas jet associated with it. This was documented in a study led by Shubham Kishore, Alok Gupta (Aryabhatta Research Institute of Observational Sciences, India) and Paul Wiita (The College of New Jersey, USA).
Confirmation of the event was also supported by observations of the NASA Swift telescopeas well as by an international collaboration that used telescopes distributed in different locations on Earth.
Professor Mauri Valtonen and his team at the University of Turku have integrated these findings into a study published in The Astrophysical Journal Letters, which demonstrates how the 12-hour burst of light came from the smaller supermassive black hole and its surroundings. Caused by the absorption of a large portion of the accretion disk (surrounding gas and dust structure) by the smaller black hole, this phenomenon results in an outward jet of gas that temporarily eclipses the larger supermassive black hole.
Representation of the galaxy OJ 287, with two black holes that can move up to 1/5 of a light year away. Photo: diffusion
What is a supermassive black hole?
A supermassive black hole is a type of extremely massive black hole found at the center of many galaxies, including our own, the Milky Way. These black holes have masses equivalent to millions or even billions of times the mass of the Sun.
Supermassive black holes are different from stellar black holes, which form when massive stars collapse under their own weight at the end of their lives. Instead, supermassive black holes are thought to grow from massive accumulations of matter during the process of galaxy formation and evolution. This matter can be gas, dust and stars that fall within the region of gravitational influence of the black hole and accumulate in an accretion disk around it.
What is a quasar?
A quasar is the name given to the monstrous event in which a black hole absorbs matter and releases large amounts of energy, including radio frequencies, visible light and X-rays, due to the rotating speed of its accretion disk, composed of gas and surrounding dust.
Contrary to black holes, where all matter is absorbed, quasars were believed to be white holes, regions into which matter escapes. “As material spirals toward black holes, a large portion of the mass is converted into energy. It is this energy that we see. Because of their great distance from us, the quasars have no real effect on Earth,” explains NASA in its educational section ‘Ask an Astrophysicist’.
When was NASA’s TESS space telescope launched?
TESS was launched in 2018 with the goal of discovering small planets orbiting bright stars across the night sky. Similar to its predecessor, the Kepler space telescope, TESS searches for exoplanets by observing small decreases in a star’s brightness, caused by a celestial body passing in front of it. In astronomy, this method is called ‘planetary transit’.
However, unlike Kepler, which focused on a limited area of the sky, TESS is carrying out an expansive survey that covers almost the entire sky. During its initial two-year mission, TESS monitored more than 200,000 stars preselected and detected more than 1,900 exoplanet candidates.
