Pismis 20
Compact cluster in constellation Circinus
From Wikipedia, the free encyclopedia
Pismis 20 is a compact open cluster in Circinus. It is located at the heart of the Circinus OB1 association in the Norma Arm of the Milky Way Galaxy.[2] Pismis 20 is about 3,270 pc away and only about 5 million years old. HD 134959, a blue supergiant variable star also called CX Circinus, is the brightest star in Pismis 20.[3]
| Star name | MV number | Effective temperature | Absolute magnitude | Bolometric magnitude | Mass (M☉) | Spectral type | Ref. |
|---|---|---|---|---|---|---|---|
| WR 67 | 11 | 56000 | -4.03 | -8 | 9 | WN6-w | [4] |
| CX Circinus (HD 134959) | 1 | 20900 | -7.9 | -9.8 | 50 | B2.5Ia | [5] |
| 6 | 42600 | -4.2 | -8.2 | 34 | B | [5] | |
| 2 | 34400 | -5.4 | -8.8 | 34 | O8.5I | [5] | |
| 3 | 28800 | -5.5 | -8.4 | 26 | B0I | [5] | |
| 7 | 30200 | -5 | -8 | 23 | B0III | [5] | |
| 4 | 29500 | -5 | -7.9 | 23 | B0.2III | [5] | |
| 5 | 30200 | -4.5 | -7.5 | 20 | B0III | [5] |
| Pismis 20 | |
|---|---|
| |
| Observation data (J2000 epoch) | |
| Right ascension | 15h 15m 23.0s[1] |
| Declination | −59° 04′ 00″[1] |
| Distance | 3,270 pc |
| Absolute magnitude (V) | 7.8 |
| Physical characteristics | |
| Estimated age | 5×106 years |
| Other designations | VDBH 170, MWSC 2281, C 1511-588, OCl 932 |
| Associations | |
| Constellation | Circinus |
