V400 Cephei

Some tens of thousands of years ago, V400 Cephei was a red giant whose outer shell expanded out into space. The core of the old giant star survives, and its energies illuminate the dissipating gases of its old outer layers to form a nebula approximately a light year in diameter. The result is the planetary nebula Caldwell 2, called the Bow-Tie Nebula because of the expanding lobes at its northern and southern ends. Imagery provided by Aladin sky atlas