The sky around vdB 118 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 118 is a reflection nebula in Sagittarius, 4,270 light-years away
vdB 118 (NGC 6589, IC 4690, LBN 43) is a reflection nebula in the constellation Sagittarius, 4,270 light-years away. spans 4′ of sky, about 5.0 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 118 is vdB 118 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 167638, B2II, magnitude 9.9. He rated it bright in brightness and moderately blue in color.
Finding vdB 118 from Kaus Borealis
vdB 118 lies 6.2° northwest of Kaus Borealis, the magnitude 2.8 star. Three fingers held at arm's length cover about 5°.
vdB 118 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 70°N, and never sets south of 70°S.
vdB 118 is 4,270 light-years away
The light seen from vdB 118 tonight left it about 4,270 years ago. It ranks 139 of 158 by distance among the Van den Bergh nebulae. Distance source: Gaia DR3 parallax of the illuminating star via AT-HYG v3.2 (1311 pc).
