Discovered by Matthias Kronberger this is an 80 arcsec planetary nebula in Cepheus. This image reveals its very faint outer “halo” that was discovered by Stefan Ziegenbalg in 2025. The irregular nature of this suggest that it is not an AGB halo but the central star of the PN is ionising some of the surrounding interstellar medium (ISM).

TARGET

Nomenclature:  Kn 31 Kronberger 31

Right Ascension: 22 27 39.19

Declination: +66 44 09.5

EQUIPMENT USED

Celestron EdgeHD 14"

10Micron GM2000 HPS mount

QHYCCD QHY268 Pr oM

IMAGE CAPTURE

Ha: 434x300" bin 1x1

OIII: 252x300" bin 1x1

Total integration: 57 hours 10 minutes

Pixel scale: 0.53 arcsec/pixel

Field radius: 0.72° × 0.57°

Capture location:  Fregenal de la Sierra, Spain

IMAGE PROCESSING

Pre-processing: Pixinsight

Post-processing: Pixinsight, Photoshop CS2