A process called ‘gravitational lensing’ has helped NASA’s Hubble Telescope focus on some of the brightest galaxies we’re aware of.
What’s big, bold, and about 10,000-times less bright than the brightest of galaxies? Our Milky Way. Sadly we’re not the brightest bulbs in the box.
But at least we know where they are.
That’s thanks to the Hubble Telescope, which relied on a phenomenon called gravitational lensing to allow its camera to peer through a tangled web of galaxies and stars to find the brightest ones.
Rings and arcs are visible, if you know what to look for, with the galaxies’ powerful gravity distorting the images of the background galaxies.
That’s according to NASA, which claims the unusual forms also may have been produced by spectacular collisions between distant, massive galaxies in a sort of cosmic demolition derby.
The galaxies pictured are experiencing “runaway star formation”, according to NASA, which means more than 10,000 new stars are being created every year.
This is a rarity. What we’re seeing is the peak of the galaxies’ star formation, and the past – these galaxies existed at least 8bn years ago.
The star-birth frenzy creates lots of dust, which enshrouds the galaxies, making them too faint to detect in visible light. But they glow fiercely in infrared light, shining as brightly as between 10trn and 100trn suns.
Hit the jackpot
“We have hit the jackpot of gravitational lenses,” said lead researcher James Lowenthal. “These ultra-luminous, massive, starburst galaxies are very rare.
“Gravitational lensing magnifies them so that you can see small details that otherwise are unimaginable. We can see features as small as about 100 light-years or less across.
“We want to understand what’s powering these monsters, and gravitational lensing allows us to study them in greater detail.”
Hubble is in its 28th year capturing images of space.
Launched aboard Discovery in April 1990 and deployed into low-Earth orbit, Hubble’s positioning outside of our planet’s atmosphere allows for stunning views.
To celebrate its ‘birthday’ in April, anniversary images featured a pair of spiral galaxies known as NGC 4302 and NGC 4298, each located 55m light years away.
Situated in the northern constellation of Coma Berenices (Berenices’ Hair), the pair were first discovered by astronomer William Herschel in 1784.
Despite appearing markedly different, they are actually quite similarly laid out – it’s our perspective that portrays a difference.
According to NASA, in NGC 4298, the tell-tale, pinwheel-like structure is visible, but it’s not as prominent as in some other spiral galaxies.
In NGC 4302, dust in the disc is silhouetted against rich lanes of stars. Absorption by dust makes the galaxy appear darker and redder than its companion. A large blue patch appears to be a giant region of recent star formation.