Object Analysis

Hanny's Voorwerp (Dutch for "Hanny's Object") is a rare type of astronomical object called a quasar ionization echo. It was discovered in 2007 by Dutch schoolteacher Hanny van Arkel while participating as a volunteer in the Galaxy Zoo project. It is located near the spiral galaxy IC 2497 in the constellation Leo Minor.

The object appears as a bright green blob of gas. The green glow comes from ionized oxygen atoms. It is believed that a quasar in the center of the nearby galaxy IC 2497 was highly active about 100,000 years ago, emitting a beam of intense radiation that illuminated the gas cloud.

The quasar has since turned off (or become much dimmer), but the light echo is still traveling through the gas cloud, keeping it ionized. This makes Hanny's Voorwerp a "fossil" record of the galaxy's past activity, visible long after the source has faded.