The Hubble Space Telescope celebrates its 25th Anniversary in space today, 24th April, with the release of this wondrous image of the giant star-cluster, Westerlund 2, in the stellar nursery, Gum 29, located 20,000 light-years away in the constellation Carina. [Image credit: Credit: NASA, ESA, the Hubble Heritage Team (STScI/AURA), A. Nota (ESA/STScI), and the Westerlund 2 Science Team]
To capture this image, Hubble’s Wide Field Camera 3 pierced through the dusty veil shrouding the stellar nursery in near-infrared light, giving astronomers a clear view of the nebula and the dense concentration of stars in the central cluster. The cluster measures between 6 to 13 light-years across.
The giant star cluster is only about 2 million years old and contains some of our galaxy’s hottest, brightest, and most massive stars. Some of its heftiest stars unleash torrents of ultraviolet light and hurricane-force winds of charged particles that etch at the enveloping hydrogen gas cloud.
The nebula reveals a fantasy landscape of pillars, ridges, and valleys. The pillars, composed of dense gas and thought to be incubators for new stars, are a few light-years tall and point to the central star cluster. Other dense regions surround the pillars, including reddish-brown filaments of gas and dust.
The brilliant stars sculpt the gaseous terrain of the nebula and help create a successive generation of baby stars. When the stellar winds hit dense walls of gas, the shockwaves may spark a new torrent of star birth along the wall of the cavity. The red dots scattered throughout the landscape are a rich population of newly forming stars still wrapped in their gas-and-dust cocoons. These tiny, faint stars are between 1 million and 2 million years old — relatively young stars — that have not yet ignited the hydrogen in their cores. The brilliant blue stars seen throughout the image are mostly foreground stars.
Because the cluster is very young — in astronomical terms — it has not had time to disperse its stars deep into interstellar space, providing astronomers with an opportunity to gather information on how the cluster formed by studying it within its star-birthing environment.
The image’s central region, which contains the star cluster, blends visible-light data taken by Hubble’s Advanced Camera for Surveys with near-infrared exposures taken by the Wide Field Camera 3. The surrounding region is composed of visible-light observations taken by the Advanced Camera for Surveys. The red colors in the nebulosity represent hydrogen; the bluish-green hues are predominantly oxygen.
And they also produce this stunning visualisation of a flight to the star cluster – “Note that the visualization is intended to be a scientifically reasonable interpretation and that distances within the model are significantly compressed”. [Credit: NASA, ESA, G. Bacon, L. Frattare, Z. Levay, and F. Summers (Viz3D Team, STScI), and J. Anderson (STScI). Acknowledgment: The Hubble Heritage Team (STScI/AURA), A. Nota (ESA/STScI), the Westerlund 2 Science Team, and ESO] [Watch on full-screen! – Ed]
In the Slugger archive you can look back to the 20th anniversary image of the Carina Nebula – and there’s a Hubblecast video outlining the telescope’s history here. [Image credit: NASA, ESA, and M. Livio and the Hubble 20th Anniversary Team (STScI)]
And, perhaps some of the best known images from Hubble over the 25 years, the Hubble [eXtreme] Deep-Field View [from 2012]. [Video credit: NASA, ESA, and G. Bacon, F. Summers, and Z. Levay (STScI)]
As the BBC spaceman’s report on Hubble’s 25th Anniversary notes
Where Hubble remains peerless is in going deep, looking far across space – and therefore far back in time – to see the very first structures to form in the Universe.
Among the telescope’s greatest contributions are undoubtedly its Deep Field observations, where it has stared at a patch of apparently blank sky for days on end to reveal the presence of thousands of very distant, extremely faint galaxies.
The latest iteration of this programme now accounts for the major fraction of telescope time.
It is called Frontier Fields, and the project requires Hubble to stare at six huge galaxy clusters.
It can use their gravity as a kind zoom lens to see what lies beyond, even further into the distance.
Jennifer Lotz, the Frontier Fields lead at STScI, explained: “They act as natural telescopes, magnifying and stretching the light of distant galaxies behind those clusters. And so by combining the power of Hubble and its very deep imaging with these natural telescopes, we really are able to see deeper into the Universe than we would without these foreground clusters.”
The next generation space telescope, the James Webb Space Telescope, is due to be launched from French Guiana in October of 2018.
Added Alternative view of Flight to Star Cluster Westerlund 2 (Slower Flight).