Hanny's Voorwerp which is Dutch for Hanny's object, is an astronomical object of unknown nature. It was discovered in 2007 by Dutch school teacher Hanny van Arkel, while she was participating as an amateur volunteer in the Galaxy Zoo project. Photographically, it appears as a bright blob close to spiral galaxy IC 2497 in the constellation Leo Minor. The object, now referred to as a "voorwerp", is about the size of our Milky Way galaxy and has a huge central hole over 16,000 light years across. The voorwerp is false colored green, a standard color to represent the presence of several luminous emission lines of glowing oxygen. So it is really not grren but represents Oxygen emissions. It has been shown to be at the same distance from Earth as the adjacent galaxy, both about 650 million light-years away. Hanny's Voorwerpmay be a small part of a 300,000-light-year-long streamer of gas, located about 650 million light-years from Earth. Scientists suggested that a quasar in a nearby galaxy, known as IC 2497, was shining on Hanny's Voorwerp, lighting up the oxygen in the streamer with a greenish glow. The only problem was that no quasar could be seen.
In the sharpest view yet of Hanny's Voorwerp, Hubble's Wide Field Camera 3 and Advanced Camera for Surveys have uncovered star birth in a region of the green object that faces the spiral galaxy IC 2497, located about 650 million light-years from Earth. (These are the yellow orange colored regions.) The object may be the beginnings of a birth of a galaxy from matter not previously ignited.
Radio observations have shown an outflow of gas arising from the galaxy's core. This clearly shows there is a relationship between the tow objects. The new Hubble images reveal that the galaxy's gas is interacting with a small region of Hanny's Voorwerp, which is collapsing and forming stars. The youngest stars are a couple of million years old.
What is this glowing mysterious object? One possibility is that it is represents the afterimage of some brighter object like a quasar that shut itself off hundred of thousands years ago. The brighter object is now invisible but the glowing gases remain from a bright blast long since extinguished.
Astronomers have spotted a radio source in the nearby galaxy that was sending out weak emissions. This could be the shut down source. Astronomers say there's a chance the quasar could switch on again if more material is dumped around the galaxy's black hole.
For further information: http://www.eurekalert.org/pub_releases/2011-01/eic-hzi011011.php