Closest pair of supermassive black holes to Earth ever discovered

Astronomers recently discovered the closest pair of supermassive black holes known to date, and the record has two meanings. They are not only the closest pair to Earth, but also the most powerful pair ever discovered.

double record

The two black holes are located in the galaxy NGC 7727, about 89 million light-years from tr. It may sound far-fetched, but in cosmological terms, it’s a stone’s throw away (previous record holders were 470 million light-years away). it is clear that Black hole The nearest supermassive remnant Sagittarius A*, which is located in the middle Milky Way, only 26,000 light-years away from our planet.

But the proximity between supermassive black holes is perhaps even more interesting. They are only 1,600 light-years apart, less than half the distance seen for previous record holders, and they keep getting closer.

« The low separation and velocity of the black holes suggests that they will merge and form one monstrous black hole, perhaps within 250 million years. ‘, he explains Holger Baumgardt, co-author of the study, recently published in the journal Astronomy and astrophysics.

The largest is located in the heart of the galaxy, with a mass of about 154 million times the mass of the galaxy Soleil, when the second displays “only” 6.3 million solar masses on the scale. Researchers believe it was originally the core of another galaxy that merged with it NGC 7727 About a billion years ago.

Many hidden supermassive black holes

Such a collision had long been suspected. NGC 7727 It is an irregular galaxy, with amorphous spiral arms and strange star currents in its outer regions. The two bright objects near the center are thought to be supermassive black holes, but this has not been confirmed.

So the study authors set out to measure the mass of these things. use multi-unit spectrophotometer (contemplation), a tool very large telescope (VLT) to me Chili pepper, to study the effect of gravity exerted by objects on the stars around them. This study found that the objects contained several million suns, making supermassive black holes the only possible candidates.

« Our discovery indicates that there may be a lot of remnants of galactic mergers, and that they may contain many hidden massive black holes still waiting to be discovered. ‘, he explains Karina Vogel, lead author of the study. ” This could increase the total number of known supermassive black holes in the local universe by 30%. »