The sky around vdB 39 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 39 is a reflection nebula in Auriga, 3,310 light-years away
vdB 39 is a reflection nebula in the constellation Auriga, 3,310 light-years away. spans 36″ of sky, about 0.6 light-years across. It is a telescope object, 6 inches or larger, and it is highest in the evening sky in January.
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 39 is vdB 39 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 243202, B5Vp, magnitude 11.2. He rated it faint in brightness and moderately blue in color.
Finding vdB 39 from Elnath
vdB 39 lies 4.2° north of Elnath, the magnitude 1.6 star. Three fingers held at arm's length cover about 5°.
vdB 39 is highest in the evening in January
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 57°S, and never sets north of 57°N.
vdB 39 is 3,310 light-years away
The light seen from vdB 39 tonight left it about 3,310 years ago. It ranks 126 of 158 by distance among the Van den Bergh nebulae. Distance source: Gaia DR3 parallax of the illuminating star via AT-HYG v3.2 (1015 pc).
