The faint planetary nebula ESO 166-21
author: Anglo-Australian Observatory/David Malin Images/Novapix
reference: a-nep98-80001
Image Size 300 DPI: 51 * 40 cm
This planetary nebula was discovered in the rich southern constellation of Vela in 1966, which is why it does not have an NGC number. The 'Ack' designation refers to its identification in the catalogue of planetary nebulae edited by Agnes Acker. This beautifully structured delicate sphere of glowing gas is about 2 arc minutes in diameter and is extremely faint. Both these characteristics have contributed to the conspicuous grain 'noise' in the photograph, and attempts to emphasise the faint nebulosity also bring out the many faint stars in this direction, including the markedly blue central star of visual magnitude 18 which is seen here sandwiched between two other, brighter stars.