The sky around vdB 155 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 155 is a reflection nebula in Cepheus, 2,650 light-years away
vdB 155 (LBN 524, DG 188) is a reflection nebula in the constellation Cepheus, 2,650 light-years away. spans 12′ of sky, about 9.6 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 155 is vdB 155 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 216629, B2pe, magnitude 9.3. He rated it moderate in brightness and blue in color.
Finding vdB 155 from ι Cep
vdB 155 lies 4.1° south of ι Cep, the magnitude 3.5 star. Three fingers held at arm's length cover about 5°.
vdB 155 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 28°S, and never sets north of 28°N.
vdB 155 is 2,650 light-years away
The light seen from vdB 155 tonight left it about 2,650 years ago. It ranks 100 of 158 by distance among the Van den Bergh nebulae. Distance source: Gaia DR3 parallax of the illuminating star via AT-HYG v3.2 (811 pc).
