Sized 16 x 12 arcmin. and of very low surface brightness,this object can be found in the constellation of Hydra.This nebula was classified earlier as Planetay Nebula,but this changed
in the latest years and today astronomers think,that Abell35 (or PN 303 +40.1) is a very unusual building of the fast rotating G8 subgiant star SAO 181201,its white-dwarf-companion in a binary sytem and a lot of material,that was emitted a few thousand years ago by this dwarf.
The collapsing star (now the white dwarf) was not massive enough for producing a planetay nebula,so we can only observe this unusual object nowadays.
The white dwarf is only 18 AU away from the G8-subgiant.
Strong UV-radiation of the dwarf (150.000°K hot) causes much OIII-glow from the surrounding shell of material.
The "bow shock" is the result of the hypersonic-(about Mach 10)-movement of the stellar system through this material cloud,best visible in the line of OIII.
This complex system, approximately 400 light years awy from us,was fist detected by George Abell in 1955.
position (epoch 2000):
RA.: 12h 53m 33s
Decl.: -22° 52′ 23″
LRGB image from:
a total of 18.0 hours
80cm f/7 AstroOptik Keller corrected cassegrain FLI Proline 16803 Astrodon LRGB GenII filters
Prompt 7 CTIO/UNC Chile,remote controlled
image processing: Bernd Flach-Wilken
this picture of Abell35 shows a sky-field 21.8´x21.8´,nearly the full FOV that´s possible with our equipment.
For full resolution click here. North is up.
in the OIII-picure you can see the "bow shock" a lot clearer: