This tiny Planetary Nebula at mag 11.2 extends to 18 arc-sec and was discovered in 1876 by Wilhelm Tempel.
It is also known as the Box Nebula, its bright parts forming a quadrupolar planetary nebula located in the constellation Ophiuchus
At extreme stretching of the image extended double-lobe features and a circulat halo can be observed.
Find here an interesting publication on NGC6309 using data from the NOT: here.
Ha-OIII-LRGB (200-200-220-120-120-120min), total 16,3 h, Seeing 0.8-1.2 arcsec, North is up;
80cm f/7 Astrooptik Keller corrected cassegrain, FLI Proline 16803, Baader Filters, Prompt 7 CTIO Chile
Processing: Johannes Schedler
Find the combined image using all data below in 110/160 % size below.