From the Southworth Planetarium
“If it’s a secret spy plane, why is it making headlines?”
THE DAILY ASTRONOMER
May 25, 2010
Hanny’s Voorwerp
“The physicist learns more and more about less and less; the astronomer learns less and less about more and more.”
Despite recent and impressive knowledge advances, this adage is still lamentably valid. Even those who have worked in astronomy for many years liken the experience to exploring an endless cavern in which the next turn might reveal discovery of an object which one did not expect and cannot yet explain. Equating our immense, complex Universe to an infinite cavern is no idle comparison.
Case in point: Hanny’s Voorweep.
Dutch school teacher Hanny van Arkel discovered this mysterious object in 2007. At the time, Ms. van Arkel was participating in the Galaxy Zoo project, a program in which citizen scientists helped catalogue millions of celestial objects, primarily galaxies, During this ambitious cataloging endeavor, van Arkel happened upon a strange cloud located within Leo Minor, a faint constellation just north of Leo the Lion.
Hanny’s Voorwerp is now known to be 700 million light years away. Unlike most extra galactic objects, Hanny’s Voorwerp has features that have left astrophysicists rather perplexed. Principal amongst these enigmatic features is a central “hole” 16,000 light years in diameter. Surrounding this hole is greenish cloud that is devoid of stars, but still curiously luminescent. Its glow is its mystery. Some scientists believe that Hanny’s Voorweep contains a “ghost image” light created by “transient quasar” radiation. This means that millions of years ago, a powerful quasar emitted copious radiation around it. Some of this energy interacted with gases within Hanny’s Voorwerp, causing it to fluoresce: a process similar to that in which the Orion Nebula re-emits photons that it absorbs from stars embedded within it.
However, with Hanny’s Voorwerp, the light source is gone, but the resultant glow remains. A bit of an eerie phenomenon, actually.
We have not yet solved the mystery of Hanny’s Voorwerp, so this explanation might be quite off-base. Not the first time suppositions have fallen short of reality. It is not likely to be the last time, either. Hence, the fun of astronomy.
The green thing is Hanny's Voorwerp.
