Iiro's DeepSky Sketches

Name: PK 144-15.1 (Abell 4)Other name: Abell 4
RA: 2h 45.4m DEC: +42° 33'
Constellation: PER
Type: Planetary nebula
Magnitude: 16.7
Size: 22''
Surface brightness: 12.4
Brightest star: 19.4
Classification: 3b
Observer: Iiro Sairanen
Location: Härskiänsaari, Ruokolahti, Finland
Date: 4/5.12.2005 22:25
Instrument: Newton 457/2280 mm
Magnification: 309xFilter: UHC
Field: 10'Seeing: 3
Background sky: 3NE lim mag: 6.4
Visuality: IIIHeight: 71°
Weather: -10°C
Description: A planetary nebula which has a very low surface brightness. Filters do improve the view but not much. Mainly an even brightness disk where might be a brightening in the middle. In the photos this planetary is a ring with very faint central star. The nearby galaxy PGC 10427 was out of sight.
Updated: 23.12.2005 18:01