Picture of the day

The Heart Nebula is an emission nebula , 7500 light years from Earth, located in the Perseus Arm of the Milky Way in the constellation Cassiopeia . It was discovered by William Herschel on 3 November 1787. Spanning almost 2 degrees in the sky, its shape is driven by stellar winds from the hot stars in its core. The nebula displays glowing ionized hydrogen gas and darker dust lanes , and is also made up of ionised oxygen and sulfur gasses, which cause rich blue and orange colours to be seen in narrowband images. This photograph of the Heart Nebula, with the Fish Head Nebula also visible in the top right corner, is a narrowband image captured on a 70mm scope with a capture period of around 44 hours. Photograph credit: Ram Samudrala