RCW 109

RCW 109 is an emission nebula (H II region) in Scorpius

RCW 109 is an emission nebula (H II region) in the constellation Scorpius. spans 2′. 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.

RCW 109 is RCW 109 in the RCW catalog of southern H-alpha regions

A. W. Rodgers, C. T. Campbell and J. B. Whiteoak listed it in their catalog of H-alpha emission regions in the southern Milky Way (1960), from photographs taken at Mount Stromlo Observatory.

Finding RCW 109 from η Sco

RCW 109 lies 5.2° southwest of η Sco, the magnitude 3.3 star. Three fingers held at arm's length cover about 5°.

RCW 109 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 44°N, and never sets south of 44°S.

The distance to RCW 109 is not well measured

Objects within 6° of RCW 109

• RCW 110, emission nebula (H II region), 1.4°
• RCW 111, emission nebula (H II region), 1.6°
• C82, open cluster, 3.2°
• RCW 107, emission nebula (H II region), 3.2°
• RCW 113, emission nebula (H II region), 3.7°
• C76, open cluster, 4.1°
• RCW 117, emission nebula (H II region), 5.9°

RCW 109 catalog data