The NASA/ESA Hubble Space Telescope was launched into orbit by a space shuttle on April 24, 1990. It was the first space telescope of its kind, and has surpassed all expectations, providing a quarter of a century of discoveries, stunning images and outstanding science. To celebrate its 28th year in orbit, some of Hubble’s precious observation time was used to observe a colossal stellar nursery called the Lagoon Nebula.
The Lagoon Nebula, also known as Messier 8 or NGC 6523, is a vast stellar nursery 55 light-year wide and 20 light-years tall.
Even though it is about 4,000 light-years away from Earth, it is about 3 times larger in the sky than the full Moon. It is even visible to the naked eye in clear, dark skies.
The Lagoon Nebula was first catalogued in 1654 by the Italian astronomer Giovanni Battista Hodierna, who sought to record nebulous objects in the night sky so they would not be mistaken for comets. Since Hodierna’s observations, the stunning nebula has been photographed and analyzed by many telescopes and astronomers all over the world.
Since it is relatively huge on the night sky, Hubble is only able to capture a small fraction of the total nebula. These new images are only about 4 light-years across, but they show stunning details.
The inspiration for Lagoon Nebula’s name may not be immediately obvious in the images. It becomes clearer only in a wider field of view, when the broad, lagoon-shaped dust lane that crosses the glowing gas of the nebula can be made out. These Hubble images, however, depict a scene at the very heart of the nebula.
Like many stellar nurseries, the Lagoon Nebula boasts many large, hot stars. Their UV radiation ionizes the surrounding gas, causing it to shine brightly and sculpting it into ghostly and other-worldly shapes.
The bright star embedded in dark clouds at the center of the images is Herschel 36.
This star is about 200,000 times brighter than our Sun, 32 times more massive and has a surface temperature of 40,000 degrees Kelvin. It is still very active because it is young by a star’s standards, only 1 million years old.
Herschel 36’s radiation sculpts the surrounding cloud by blowing some of the gas away, creating dense and less dense regions.
Among the sculptures created by this star are two interstellar twisters — eerie, rope-like structures that each measures half a light-year in length.
These features are quite similar to their namesakes on Earth — they are thought to be wrapped into their funnel-like shapes by temperature differences between the hot surfaces and cold interiors of the clouds.
At some point in the future, these clouds will collapse under their own weight and give birth to a new generation of stars.
Hubble observed the Lagoon Nebula not only in visible light but also at infrared wavelengths.
While the observations in the optical allow astronomers to study the gas in full detail, the infrared light cuts through the obscuring patches of dust and gas, revealing the more intricate structures underneath and the young stars hiding within it.
Only by combining optical and infrared data can astronomers paint a complete picture of the ongoing processes in the nebula.