The sky around Rho Ophiuchi Nebula 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.
Rho Ophiuchi Nebula is a reflection nebula in Ophiuchus, 449 light-years away
Rho Ophiuchi Nebula (vdB 106, IC 4604, LBN 1111, Ced 131b) is a reflection nebula in the constellation Ophiuchus, 449 light-years away. spans 1° of sky, about 7.8 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.
Rho Ophiuchi Nebula is vdB 106 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 Rho Oph, HD 147933/147934, B2IV, magnitude 4.6. He rated it bright in brightness and very blue in color.
Finding Rho Ophiuchi Nebula from Antares
Rho Ophiuchi Nebula lies 3.1° north of Antares, the magnitude 1.1 star. Three fingers held at arm's length cover about 5°.
Rho Ophiuchi Nebula 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 67°N, and never sets south of 67°S.
Rho Ophiuchi Nebula is 449 light-years away
The light seen from Rho Ophiuchi Nebula tonight left it about 449 years ago, around 1577 AD. It ranks 13 of 158 by distance among the Van den Bergh nebulae. Distance source: Gaia DR3 parallax of the illuminating star via AT-HYG v3.2 (138 pc).
