CED 90

Ced 90 (also known as Gum 3) is an emission and reflection nebula visible in the constellation Canis Major. It is a large H II region connected to a molecular nebula complex where star formation occurs. It is one of the most conspicuous and luminous nebulae in the nebulous complex to which it belongs. The gas in the cloud is partly ionized and partly illuminated by reflection due to radiation from the star HD 53623, a blue giant of spectral type B1III and magnitude 7.99, part of the OB association Canis Major R1, which in turn is part of the larger association Canis Major OB1, whose main characteristic is its connection with extensive reflection nebulae.