With this new view of a spectacular stellar nursery ESO is celebrating 15 years of the Very Large Telescope — the world's most advanced optical instrument. This picture reveals thick clumps of dust silhouetted against the pink glowing gas cloud known to astronomers as IC 2944. These opaque blobs resemble drops of ink floating in a strawberry cocktail, their whimsical shapes sculpted by powerful radiation coming from the nearby brilliant young stars.
This new picture celebrates an important anniversary for the Very LargeTelescope - it is fifteen years since the first light on the first of its fourUnit Telescopes, on 25 May 1998. Since then the four original giant telescopeshave been joined by the four small Auxiliary Telescopes that form part of theVLT Interferometer (VLTI). The VLT is one of the most powerful and productiveground-based astronomical facilities in existence. In 2012 more than 600refereed scientific papers based on data from the VLT and VLTI were published([ann13009]).
Interstellar clouds of dust and gas are the nurseries where new stars are bornand grow. The new picture shows one of them, IC 2944, which appears as thesoftly glowing pink background [1]. This image is the sharpest view of theobject ever taken from the ground [2]. The cloud lies about 6500 light-yearsaway in the southern constellation of Centaurus (The Centaur). This part ofthe sky is home to many other similar nebulae that are scrutinised byastronomers to study the mechanisms of star formation.
Emission nebulae like IC 2944 are composed mostly of hydrogen gas that glowsin a distinctive shade of red, due to the intense radiation from the manybrilliant newborn stars. Clearly revealed against this bright backdrop aremysterious dark clots of opaque dust, cold clouds known as Bok globules. Theyare named after the Dutch-American astronomer Bart Bok, who first drewattention to them in the 1940s as possible sites of star formation. Thisparticular set is nicknamed the Thackeray Globules [3].
This intriguing new view of a spectacular stellar nursery IC 2944 is being released to celebrate a milestone: 15 years of ESO's Very Large Telescope. This image also shows a group of thick clouds of dust known as the Thackeray globules silhouetted against the pale pink glowing gas of the nebula. These globules are under fierce bombardment from the ultraviolet radiation from nearby hot young stars. They are both being eroded away and also fragmenting, rather like lumps of butter dropped onto a hot frying pan. It is likely that Thackeray's globules will be destroyed before they can collapse and form new stars.
(Photo Credit: ESO)
Larger Bok globules in quieter locations often collapse to form new stars butthe ones in this picture are under fierce bombardment from the ultravioletradiation from nearby hot young stars. They are both being eroded away andalso fragmenting, rather like lumps of butter dropped into a hot frying pan.It is likely that Thackeray's Globules will be destroyed before they cancollapse and form stars.
Bok globules are not easy to study. As they are opaque to visible light it isdifficult for astronomers to observe their inner workings, and so other toolsare needed to unveil their secrets -- observations in the infrared or in thesubmillimetre parts of the spectrum, for example, where the dust clouds, onlya few degrees over absolute zero, appear bright. Such studies of the Thackerayglobules have confirmed that there is no current star formation within them.
This region of sky has also been imaged in the past by the NASA/ESA [HubbleSpace Telescope] [opo0201a]. This new view from the FORSinstrument on ESO's Very Large Telescope at the Paranal Observatory innorthern Chile [4] covers a wider patch of sky than Hubble and shows a broaderlandscape of star formation.
Source: ESO