The sky around vdB 105 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 105 is a reflection nebula in Ophiuchus, 445 light-years away
vdB 105 (IC 4603, LBN 1109, Ced 131a) is a reflection nebula in the constellation Ophiuchus, 445 light-years away. spans 20′ of sky, about 2.6 light-years across. It is a telescope object, 6 inches or larger, and it is highest in the evening sky in July.
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 105 is vdB 105 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 147889, B2III/IV, magnitude 7.9. He rated it moderate in brightness and moderately blue in color.
Finding vdB 105 from Antares
vdB 105 lies 2.2° northwest of Antares, the magnitude 1.1 star. That is within one binocular field.
vdB 105 is highest in the evening in July
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 66°N, and never sets south of 66°S.
vdB 105 is 445 light-years away
The light seen from vdB 105 tonight left it about 445 years ago, around 1581 AD. It ranks 12 of 158 by distance among the Van den Bergh nebulae. Distance source: Gaia DR3 parallax of the illuminating star via AT-HYG v3.2 (136 pc).
