The sky around vdB 70 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 70 is a reflection nebula in Monoceros, 2,830 light-years away
vdB 70 (LBN 990, DG 91) is a reflection nebula in the constellation Monoceros, 2,830 light-years away. spans 24′ of sky, about 20 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 70 is vdB 70 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 42050, B2III, magnitude 8.1. He rated it faint in brightness and intermediate in color.
Finding vdB 70 from Saiph
vdB 70 lies 6.7° northeast of Saiph, the magnitude 2.1 star. Three fingers held at arm's length cover about 5°.
vdB 70 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 85°N.
vdB 70 is 2,830 light-years away
The light seen from vdB 70 tonight left it about 2,830 years ago. It ranks 106 of 158 by distance among the Van den Bergh nebulae. Distance source: Gaia DR3 parallax of the illuminating star via AT-HYG v3.2 (867 pc).
