There are plenty of bizarre stars in the universe, but if one had to be singled out as perhaps the strangest of them all, S301 would be a strong contender.

The name may sound ordinary, and ironically, there is nothing particularly unusual about the star itself. S301 is broadly similar to the Sun, although it is somewhat more massive, hotter and brighter. The Milky Way is filled with billions of stars like it.

What makes S301 extraordinary is not the star itself, but where it lives.

S301 orbits Sagittarius A* (Sgr A*), the supermassive black hole at the exact centre of the Milky Way. Its location places the star in an extreme gravitational environment where space and time are dramatically distorted.

With a mass roughly 4.3 million times that of the Sun, Sgr A* dominates the region around it. Its immense gravity controls a vast collection of objects, including the S-star cluster—a group of stars orbiting close to the black hole. Astronomers have identified dozens of bright stars in the cluster, although many more faint stars are likely hidden behind the enormous clouds of dust lying between the galactic centre and Earth.

Powerful infrared telescopes have allowed astronomers to peer through that dust and track some of these stars as they race around Sgr A*. Most follow highly elliptical orbits, swinging close to the black hole before travelling much farther away.

Until recently, the record for the closest approach belonged to a star known as S2, which comes within about 18 billion kilometres of Sgr A*.

That record was shattered in August 2026, when astronomers announced the discovery of S301.

Following its extraordinarily elongated orbit, S301 passes within roughly 1.7 billion kilometres of the black hole—a distance only somewhat greater than the average separation between the Sun and Saturn.

The result is a view of the cosmos unlike anything experienced by any other known star in the Milky Way.

In 2022, the Event Horizon Telescope collaboration released the first image of Sgr A*, revealing a bright, doughnut-shaped ring of material surrounding the black hole. At its centre lies the black hole's shadow—the dark region around Sgr A* where light can orbit before eventually falling inward.

From S301's vantage point, that shadow would appear enormous. At its closest approach, it would span more than a degree across the star's sky—over twice the apparent diameter of the full Moon as seen from Earth.

The glowing material surrounding Sgr A* would appear even larger, stretching roughly four degrees across the sky—about half the apparent width of an outstretched fist.

And while Earth-based radio telescopes working together can only barely resolve that structure as a fuzzy ring, S301 would have a dramatically better view simply by looking up.

But being this close to a supermassive black hole would come with an enormous price.

Astronomers have found evidence that around 200 years ago, material plunging into Sgr A* became so hot that it produced powerful X-ray flares. At their peak, these eruptions released energy at rates hundreds of thousands of times greater than the Sun's total luminosity.

For a star passing just 1.7 billion kilometres away, that would represent a potentially lethal dose of radiation.