Hubble’s Serendipitous Snapshot

The mysterious and beautiful nebula called IRAS 05437+2502 billows out among the bright stars and dark dust clouds that surround it in this striking image from the Hubble Space Telescope. The nebula occupies a tiny space in the constellation Taurus just 1.6′ across or 1/18th the diameter of the full moon. The photo was taken through yellow and near-infrared filters. ESA/Hubble, R. Sahai and NASA

A little-known nebula called IRAS 05437+2502 glows faintly above the horns of Taurus the Bull. Its name belies its discoverer, the Infrared Astronomical Satellite (IRAS), which first detected the cloud in 1983 in infrared light. We sense infrared light as heat, but a telescope with a mirror made of the proper materials and chilled to near absolute zero can take pictures of celestial objects by the infrared light they emit.

The orbiting IRAS telescope’s mirrors were made of beryllium, a strong and light silvery-white metal coated with a fine layer of gold, a good reflector of infrared light. Since infrared light is basically a form of heat, engineers had to chill the mirrors with liquid helium to –452° F (–269° C) otherwise the ambient heat coming from the material would have completely washed out the photos.

IRAS was the first space telescope to survey the whole sky in infrared light. It discovered hundreds of new objects invisible from the ground. NASA

Unlike many of Hubble’s targets, this stunning nebula hasn’t been studied in detail, and its exact nature is unclear. At first glance it looks like a small star-forming region with billowy clouds of dust and gas sculpted by fierce ultraviolet radiation from bright, young stars. And while that may be partially true, the bright, boomerang-shaped feature may hint at something more sensational.

Astronomers think it was created by a star racing across the nebula at some 124,000 miles an hour (200,000 km/hour) and interacting with the gases to create the sharp-edged, bright arc. Stars can reach these speeds when they’re flung out of their birth star cluster into the wilds of interstellar space through gravitational interactions with other cluster members. Where the star is now is anyone’s guess.

IRAS 05437+2502 is a reflection nebula, the same kind you’ll see around the Pleiades star cluster and caused by light reflecting off clouds of interstellar dust.

We’re lucky to have such a thought provoking image. Hubble took it as part of a “snapshot” survey. These are observations that are fitted into Hubble’s busy schedule when possible, without any guarantee that the observation will take place. It’s fortunate it happened at all!

If you can cross your eyes, you can view the nebula in 3D here.