Hubble and Webb capture the 'Cat's Head Nebula' in Carina

Just in time for Halloween, ESA and NASA have released new images of a star-forming cloud that looks like a cat sitting with its back to us. The Cat's Head Nebula is a small part of the huge Carina Nebula, about 7,500 light-years from Earth. The Hubble Space Telescope and the James Webb Space Telescope both observed it, and their views show very different things.

A pillar shaped by giant stars

According to ESA/Hubble, the cat shape was probably carved over time by ultraviolet radiation and winds from the massive stars in the Carina Nebula. As this "stellar feedback" wears away the surrounding gas and dust, denser material inside the pillar resists for now. The scene is temporary: as new stars form and evolve, it will eventually disperse.

What Hubble sees

In visible light, Hubble shows an opaque, dark brown pillar of dust. The cat's glowing red eye may be a young star still partly buried in dust. A hazy yellow ridge along the right edge is gas being heated and ionised by ultraviolet light from nearby massive stars, which may be slowly evaporating it. Hubble's filters pick up light from oxygen, hydrogen and sulphur, so the surrounding gas glows from blue and cyan at the top to orange and red at the bottom.

What Webb adds

Webb looks in infrared light, which passes through dust far better. In its near-infrared image the pillar becomes more transparent and its surface detail appears, along with a dense field of stars. Some of those stars are still wrapped in dust, the eye is still visible, and faint background galaxies show through our own Milky Way.

The mid-infrared view traces warm dust and carbon-based molecules. It brings out delicate globules and strands on the left of the pillar. To the right sits a bright yellow source that is likely an infant star embedded in dust. A thin filament seems to cross it, though ESA notes the image alone cannot show whether the two are physically linked.

Why two telescopes

Star formation happens inside dust clouds that hide it from visible-light telescopes. Combining Hubble's view of the cloud's surface with Webb's view inside it helps astronomers study how stars form, a process that is still chaotic and not fully understood.

The Carina Nebula is a southern-sky object and lies too far south to see from Ukraine or most of Europe. If you want to explore the sky yourself, our beginner telescope guide and our tips on night-sky photography with a phone are good places to start.