RCW 42

RCW 42 is an emission nebula (H II region) in Vela

RCW 42 (Gum 26) is an emission nebula (H II region) in the constellation Vela. spans 9′. It is a telescope object, 6 inches or larger, and it is highest in the evening sky in March.

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 42 is RCW 42 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.

RCW 42 is Gum 26 in Colin Gum's survey of southern H II regions

Colin Gum listed it in his survey of H II regions of the southern Milky Way (1955), the first photographic survey of the southern emission nebulae, made at Mount Stromlo Observatory.

Finding RCW 42 from Markeb

RCW 42 lies 3.0° north of Markeb, the magnitude 2.5 star. Three fingers held at arm's length cover about 5°.

RCW 42 is highest in the evening in March

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 38°N, and never sets south of 38°S.

The distance to RCW 42 is not well measured

Objects within 6° of RCW 42

• RCW 43 Flying Jaw Nebula, planetary nebula, 4.1°
• RCW 41, emission nebula (H II region), 4.2°
• RCW 44, planetary nebula, 4.4°
• RCW 40, emission nebula (H II region), 4.8°
• RCW 39, emission nebula (H II region), 4.9°

RCW 42 catalog data