The image of the black hole M87* at the top of this page was captured by a group of ground-based telescopes around the world acting in unison, effectively creating a single Earth-sized telescope that is called the Event Horizon Telescope.īecause black holes are formed at the end of a large star's life, black holes are scattered throughout galaxies.

Astronomers can detect and study black holes by finding those discs and jets. However, black holes that are actively feeding on nearby stars or clouds of gas falling towards their centre will often be surrounded by bright discs or jets.

Since light cannot escape a black hole, it is impossible to actually see what one looks like.

The gas being pulled rapidly into a black hole can reach millions of degrees. Supermassive black holes are even colder.īut a black hole's event horizon is incredibly hot. Stellar black holes are very cold: they have a temperature of nearly absolute zero – which is zero Kelvin, or −273.15 degrees Celsius. The more massive a black hole, the colder it is. They can range from 10 times to several billion times the mass of our Sun. The boundary surrounding a black hole, known as the event horizon, varies in size.

The black hole M87* (located at the centre of Messier 87, one of the most massive galaxies in the observable universe) is the subject of the first-ever picture of a black hole, released in April 2019.Ī black hole's singularity is an infinitely tiny point in its innermost region.

The black hole at the centre of our galaxy, the Milky Way, is known as Sagittarius A*.

In this video, learn more about black holes with Sarah Gallagher, astrophysicist and Science Advisor to the President of the Canadian Space Agency ( CSA). Scientists are still not sure how supermassive black holes are created, although they may be formed through mergers of smaller, stellar black holes.

Supermassive black holes, which are found at the centre of most galaxies and can be millions or even billions of times more massive than the Sun.

Stellar black holes, which are the most common and contain about 10 times the mass of our Sun.

The gravity of a black hole is so strong that nothing – not even light – can escape its pull.īlack holes are generally categorized according to the mass they contain. All of the former star's matter is then concentrated into a single tiny point (known as a singularity). The core of the star collapses in on itself, causing a supernova – a massive explosion of the star's outer layers. A black hole is created after the death of a very massive star.

(Credit: Event Horizon Telescope Collaboration) DescriptionĪ black hole is a region of space having a gravitational field so intense that no matter or radiation can escape.

This is the first real image of a black hole ever captured.

Blackhole names