Thackeray-globules

The Lagoon nebula in a closer and deeper look

The central structure of the nebula , normally overexposed (upper left) is revealed in this image. Seen in silhouette just lower from the center of the view are small, dark clouds of obscuring cosmic dust. These globules are called Thackeray’s Globules for their discoverer, and are potential sites for the formation of new stars, but likely being eroded by the intense radiation from the nearby young stars.

Image credit: Kfir Simon

THACKERAY’S GLOBULES

In the rich star fields of IC 2944 (sometimes called the Running Chicken nebula), dense clouds of dust and gas called Bok globules may be busy forming stars. These scattered, opaque clouds are known as Thackeray’s Globules, and the largest of the bunch has gained some notoriety for its shape, which vaguely resembles Australia. It’s likely that the shape is actually two separate clouds that happen to overlap from our vantage point. 

The young stars of this open cluster give off intense ultraviolet radiation that causes the emission nebula around them to glow. Observation has shown that the radiation may also be causing the dark globules to churn and break apart, rather than collapsing to form Sun-like stars. 

Little is known about the origin of Bok globules. They are frequently found in areas of high star formation known as “HII regions” due to the presence of hydrogen gas, here represented by the vibrant yellow glow. 

-RLO

Image: T. Rector (U. Alaska Anchorage), & N.S. van der Bliek (NOAO/AURA/NSF)
Sources: 1, 2, 3

(ESO via Wired Science)  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.