In the nebula, which lies around 6500 light-years from Earth, hot newborn stars that formed from clouds of hydrogen gas shine brightly with ultraviolet light. This intense radiation in turn excites the surrounding hydrogen cloud, making it glow a distinctive shade of red. This red shade is typical of star-forming regions, another famous example being the Lagoon Nebula (eso0936 – http://www.eso.org/public/news/eso0936/).
Some people see a chicken shape in pictures of this red star-forming region, giving the nebula its nickname — though there is some disagreement over exactly which part of the nebula is chicken shaped, with various bird-like features in evidence across the picture [1].
Aside from the glowing gas, another sign of star formation in IC 2944 is the series of opaque black clumps silhouetted against the red background in part of this image. These are examples of a type of object called Bok globules. They appear dark as they absorb the light from the luminous background. However, observations of these dark clouds using infrared telescopes, which are able to see through the dust that normally blocks visible light, have revealed that stars are forming within many of them.
The most prominent collection of Bok globules in this image is known as Thackeray’s Globules, after the South African astronomer who discovered them in the 1950s. Visible among a group of bright stars in the upper right part of the image, these globules feature in a famous image taken by the NASA/ESA Hubble Space Telescope.
While Hubble offers greater detail in its image of this small area, the Wide Field Imager on the MPG/ESO 2.2-metre telescope at ESO’s La Silla Observatory captures a much larger panorama in its images, covering an area of sky roughly the size of the full Moon [2]. Much like a zoom lens on a camera lets a photographer choose the most appropriate field of view when taking a picture, the dramatically different viewpoints offered by different telescopes can offer complementary data to scientists studying astronomical objects which cover an extended area of the sky.
If the stars cocooned in Thackeray’s Globules are still gestating, then the stars of cluster IC 2948, embedded within the nebula, are their older siblings. Still young in stellar terms, at just a few million years old, these stars shine brightly, and their ultraviolet radiation provides much of the energy that lights up the nebula. These glowing nebulae are relatively short-lived in astronomical terms (typically a few million years), meaning that the Lambda Centauri Nebula will eventually fade away as it loses both its gas and its supply of ultraviolet radiation.
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Notes
[1] Ideas for where the chicken outline lies on the picture can be submitted through the Your ESO Pictures Flickr (http://www.flickr.com/groups/youresopictures) for a chance to win some interesting prizes.
[2] This image was produced as part of the ESO Cosmic Gems programme. This is a new initiative to produce images of interesting, intriguing or visually attractive objects using ESO telescopes, for the purposes of education and public outreach. The programme makes use of small amounts of observing time, combined with otherwise unused time on the telescopes’ schedules so as to minimise the impact on science observations. All data collected are also made available to astronomers through ESO’s science archive.
More information
ESO, the European Southern Observatory, is the foremost intergovernmental astronomy organisation in Europe and the world’s most productive astronomical observatory. It is supported by 15 countries: Austria, Belgium, Brazil, the Czech Republic, Denmark, France, Finland, Germany, Italy, the Netherlands, Portugal, Spain, Sweden, Switzerland and the United Kingdom. ESO carries out an ambitious programme focused on the design, construction and operation of powerful ground-based observing facilities enabling astronomers to make important scientific discoveries. ESO also plays a leading role in promoting and organising cooperation in astronomical research. ESO operates three unique world-class observing sites in Chile: La Silla, Paranal and Chajnantor. At Paranal, ESO operates the Very Large Telescope, the world’s most advanced visible-light astronomical observatory and two survey telescopes. VISTA works in the infrared and is the world’s largest survey telescope and the VLT Survey Telescope is the largest telescope designed to exclusively survey the skies in visible light. ESO is the European partner of a revolutionary astronomical telescope ALMA, the largest astronomical project in existence. ESO is currently planning a 40-metre-class European Extremely Large optical/near-infrared Telescope, the E-ELT, which will become “the world’s biggest eye on the sky”.
Links
– Hubble Space Telescope closeup of Thackeray’s Globules in the Running Chicken Nebula: http://www.spacetelescope.org/images/opo0201a/
– ESO Cosmic Gems page: http://www.eso.org/public/outreach/gems.html
Contacts
Richard Hook
ESO, La Silla, Paranal, E-ELT and Survey Telescopes Public Information Officer
Garching bei Muenchen, Germany
Tel: +49 89 3200 6655
Email: rhook@eso.org
