R Coronae Australis: A New Kind of “Starry Night”

Dr. Who take note: If Vincent van Gogh could’ve hung about longer in 2010, he might have discovered an unexpected affinity for really big telescopes.

At least, this new picture of the nebulous region around the star R Coronae Australis certainly invokes the famed Impressionist’s “Starry Night” on a truly cosmic scale.


—Picture courtesy ESO

The picture shows what’s known as a reflection nebula. Such clouds of gas and dust are too unenergetic to glow with their own light, and instead shine mostly with light reflected from nearby stars.

In this case, the nebula surrounds a star-forming region filled with young, hot bodies still partially shrouded by the envelopes of matter from which they sprung into being. [Poetic, no?]

The sections that shine in shades of pale indigo are regions of fine dust reflecting starlight. Darker portions show where the dust is so dense, all light gets absorbed. Finding the stars hidden inside would require seeing in infrared rather than optical wavelengths.

Still, some reflection nebulae are bright enough to spot from the ground using plain old eyes, such as the famed Orion Nebula (picture) in, you guessed it, the constellation Orion.

But though it shines in this image, the nebula around R Coronae Australis, as well as the star itself, isn’t visible to the naked eye. All we can see from Earth is the crown-shaped constellation Corona Australis, which we now know houses the cloud.

And even that tiny road sign is hard to find unless you have clear, dark skies and a good view of the larger constellation Sagittarius, which sits nearby.

For Earth-bound artists to get a truly inspirational view of the wispy cloud–which sits some 420 light-years away–you need something like the professional ‘scope that took this picture: the MPG/ESO 2.2-meter telescope at the European Southern Observatory’s La Silla site in Chile.

It’s not the Musée d’Orsay, to be sure, but I hear if you really want to see a starry night, the high desert of the Atacama is a hard place to beat.

Human Journey