Planetary Nebula Humason 1-1
History
The planetary nebula Hu 1-1 (PN G119.6-06.7, PK 119-06.1), was discovered on 9 November 1920 by Milton Lasell Humason with spectrograms made with the 10 inch Cooke telescope on Mount Wilson Observatory. On 11 October in the same year he discovered another PN (Humason 1-2). He wrote: «Edwin Hubble observed both objects visually with the 60 inch reflector on December 9 1920. Each appeared as a small disk about 5" in diameter, the first being irregular in outline, the second nearly circular.» [504] However, there must have been a mix-up as Hu 1-1 has a round shape and Hu 1-2 is bipolar.
Physical Properties
| Designations | PN G119.6-06.7: Hu 1-1, PK 119-06.1, ARO 18, VV 3, VV' 5 |
| Right Ascension (J2000.0) | 00h 28m 15s |
| Declination (J2000.0) | +55° 57' 55" |
| Dimensions | 5." (optical), 10." (radio) |
| Radial Velocity | -53.7 ± 3.0 km/s |
| Expansion Velocity | 15.5 (O-III) 27.5 (N-II) km/s |
| C-Star Designations | AG82 4 |
| C-Star Magnitude | V: 19.15 |
| C-Star Spectral Type | A ? |
| Discoverer | HUMASON 1921 |
Finder Chart
The planetary nebula Hu 1-1 is located inthe constellation Cassiopeia. On 30 September it is in opposition to the Sun and crosses the meridian at local midnight. In the months July to January it can be seen best.
