The Milky Way's crowded centre
A new infrared image from the Spitzer Space Telescope has revealed the heart of the Milky Way to be a place glowing with stars and excited gas.
It is all but impossible to see the heart of our Galaxy in visible light but the centre of the Milky Way glows colourfully in this new image from NASA's Spitzer Space Telescope.
It has been taken in infrared light, which penetrates the shroud of dust to give an unprecedented view.
The myriad of stars crowding the galactic centre creates a blue haze that brightens towards the central star cluster, 26,000 lightyears from Earth. It’s so distant that Spitzer picks this up as a single glowing blotch, which is the light from the thousands of individual stars.
Astronomers have determined that these stars are orbiting a massive black hole, which lies at the very centre of the galaxy.
The green features are from carbon-rich dust molecules, called polycyclic aromatic hydrocarbons, which are illuminated by the surrounding starlight. The yellow-red patches are the thermal glow from warm dust.
The region pictured here is immense. It has a horizontal span of 2,400 lightyears and a vertical span of 1,360 lightyears.