RCW 90

RCW 90 is a planetary nebula in Circinus

RCW 90 (PN G320.9+02.0) is a planetary nebula in the constellation Circinus. spans 1′. It is a telescope object, 6 inches or larger, and it is highest in the evening sky in June.

Planetary nebula: a shell of gas thrown off by a dying Sun-like star and lit by the hot core left behind, which becomes a white dwarf. The name comes from their small, round, planet-like look in early telescopes.

RCW 90 is RCW 90 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 90 from Rigil Kentaurus

RCW 90 lies 5.9° northeast of Rigil Kentaurus, the magnitude -0.0 star. Three fingers held at arm's length cover about 5°.

RCW 90 is highest in the evening in June

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 34°N, and never sets south of 34°S.

The distance to RCW 90 is not well measured

Objects within 6° of RCW 90

• C88, open cluster, 23′
• RCW 87, emission nebula (H II region), 1.5°
• RCW 88, emission nebula (H II region), 1.8°
• RCW 92, emission nebula (H II region), 1.9°
• RCW 91, emission nebula (H II region), 2.6°
• RCW 89, supernova remnant, 3.2°
• RCW 93, planetary nebula, 4.9°
• RCW 94, emission nebula (H II region), 5.3°

RCW 90 catalog data