Astronomy Picture of the Day

Explanation: The ghosts of five supernovas haunt this extraordinary image. It was acquired at Oukaïmeden Observatory in Morocco with approximately 200 hours of observations and shows a large patch of the sky, equivalent to the area of one thousand full moons tiled together, in the constellation of Auriga (the charioteer). From left to right, the five supernova remnants visible across the field are G181.1+9.5, G182.4+4.3, G179.0+2.6, G180.0−1.7 (Sh2-240, the Spaghetti Nebula), and G178.2−4.2. They are highlighted in the annotated image, together with open cluster M37 and the Tadpole Nebula. As each explosion expanded into space, it created a growing shell of shocked gas and delicate filamentary structures shown in red (hydrogen) and blue (oxygen), respectively. These ancient stellar explosions happened independently; they are at various distances up to about several thousands of light-years away from Earth and have estimated ages up to tens of thousands of years old. Early humans may have witnessed them as bright new stars, fading over weeks or months.