The sky around vdB 131 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 131 is a reflection nebula in Cygnus, 3,230 light-years away
vdB 131 (LBN 274) is a reflection nebula in the constellation Cygnus, 3,230 light-years away. spans 11′ of sky, about 11 light-years across. It is a telescope object, 6 inches or larger, and it is highest in the evening sky in September.
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 131 is vdB 131 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 BD+41 3731, B3N, magnitude 9.9. He rated it bright in brightness and very blue in color.
Finding vdB 131 from Sadr
vdB 131 lies 2.1° north of Sadr, the magnitude 2.2 star. That is within one binocular field.
vdB 131 is highest in the evening in September
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 48°S, and never sets north of 48°N.
vdB 131 is 3,230 light-years away
The light seen from vdB 131 tonight left it about 3,230 years ago. It ranks 125 of 158 by distance among the Van den Bergh nebulae. Distance source: Gaia DR3 parallax of the illuminating star via AT-HYG v3.2 (991 pc).
