The sky around vdB 157 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 157 is a reflection nebula in Cepheus, 1,080 light-years away
vdB 157 is a reflection nebula in the constellation Cepheus, 1,080 light-years away. spans 4.6′ of sky, about 1.4 light-years across. It is a telescope object, 6 inches or larger, and it is highest in the evening sky in October.
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 157 is vdB 157 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 217903, B9V, magnitude 8.1. He rated it faint in brightness and very blue in color.
Finding vdB 157 from Errai
vdB 157 lies 5.4° southwest of Errai, the magnitude 3.2 star. Three fingers held at arm's length cover about 5°.
vdB 157 is highest in the evening in October
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 northern hemisphere and south to about 17°S, and never sets north of 17°N.
vdB 157 is 1,080 light-years away
The light seen from vdB 157 tonight left it about 1,080 years ago, around 946 AD. It ranks 44 of 158 by distance among the Van den Bergh nebulae. Distance source: Gaia DR3 parallax of the illuminating star via AT-HYG v3.2 (333 pc).
