The Lobster Claw and the Bubble

This wide field sweeps across a teeming corner of the constellation of Cassiopeia, where several clouds of gas and star clusters rub shoulders. Two shapes stand out at once: a lobster claw and an almost perfect bubble.

The Lobster Claw (Sh2-157) is a cloud of hydrogen glowing some 8,000 to 11,000 light-years away. Its claw shape was carved by the winds and radiation of young massive stars, which pushed the gas from the centre out toward the edges.

Not far off floats the Bubble (NGC 7635), an almost perfect sphere about 7 light-years across, inflated within a cloud of hydrogen. At its heart, a young, massive star, around forty times heavier than the Sun, blows a wind so powerful that it pushes the surrounding gas out into a shell.

The rest of the field is full of treasures: star clusters such as M52, and clouds where new stars are still being born. A particularly lively corner of the sky.