The sky around vdB 116 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 116 is a reflection nebula in Sagittarius, 4,570 light-years away
vdB 116 is a reflection nebula in the constellation Sagittarius, 4,570 light-years away. spans 1.2′ of sky, about 1.6 light-years across. It is a telescope object, 6 inches or larger, and it is highest in the evening sky in August.
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 116 is vdB 116 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 166288, B5Ib, magnitude 10.1. He rated it faint in brightness and blue in color.
Finding vdB 116 from Kaus Borealis
vdB 116 lies 8.7° northwest of Kaus Borealis, the magnitude 2.8 star. A fist held at arm's length covers about 10°.
vdB 116 is highest in the evening in August
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 72°N, and never sets south of 72°S.
vdB 116 is 4,570 light-years away
The light seen from vdB 116 tonight left it about 4,570 years ago. It ranks 145 of 158 by distance among the Van den Bergh nebulae. Distance source: Gaia DR3 parallax of the illuminating star via AT-HYG v3.2 (1400 pc).
