The sky around vdB 90 at true scale, north up and east left, with stars to magnitude 8. The circles show the field of a low-power eyepiece and of 10×50 binoculars.
vdB 90 is a reflection nebula in Canis Major, 3,330 light-years away
vdB 90 is a reflection nebula in the constellation Canis Major, 3,330 light-years away. spans 16′ of sky, about 15 light-years across. It is a telescope object, 6 inches or larger, and it is highest in the evening sky in February.
Nebula: a cloud of gas and dust. Emission nebulae glow on their own, lit by ultraviolet light from hot young stars; reflection nebulae shine by starlight scattered from dust; dark nebulae block the light behind them.
vdB 90 is vdB 90 in the Van den Bergh catalog of reflection nebulae
Sidney van den Bergh listed it in his catalog of reflection nebulae (1966), drawn from the Palomar Sky Survey. He chose nebulae lit by a star bright enough to appear in the Bonner and Cordoba star catalogs. The star that lights it is HD 52942, B2V(+B), magnitude 8.1. He rated it faint in brightness and intermediate in color.
Finding vdB 90 from Sirius
vdB 90 lies 6.8° northeast of Sirius, the magnitude -1.4 star. Three fingers held at arm's length cover about 5°.
vdB 90 is highest in the evening in February
The chart gives its height above the horizon at 9 pm through the year, from 60°N to 40°S. It can be seen from the whole southern hemisphere and north to about 79°N, and never sets south of 79°S.
vdB 90 is 3,330 light-years away
The light seen from vdB 90 tonight left it about 3,330 years ago. It ranks 127 of 158 by distance among the Van den Bergh nebulae. Distance source: Gaia DR3 parallax of the illuminating star via AT-HYG v3.2 (1021 pc).
