18th September 2004
M15 Globular cluster
Magnitude: 6.2 Size: 12.3'
Pease 1 Planetary Nebula
Mag.= 14.9, Surface Brightness: 6, size: 1"
Right ascension: 21h 30m 12s Declination: +12° 11' 18"
200mm F5 newtonian @ F5, SC1.5 toucam webcam RAW mode. IR + OIII filters
80mm F5 refractor @ F10 guidescope with SC1 toucam and GuideDog
100x25s frames. Captured in K3, debayered in AVIRaw, stacked in Registax, curves in photoshop.
M15 contains its own planetry nebula called Pease 1. Please see the finder details to Pease 1 here.
Pease 1 is the small blue mark, indicated by the lines, north west of the very brightest part of M15. This image was taken and processed to show Pease 1, M15 does not show at its best.
The lower image is resampled in registax and slightly unsharped to show the Pease 1 region more clearly. The blue nebula stands out strongly against the background of unresolved stars.
I have heard reports that its a challange to find this object visually in large telescopes - however it shows up clearly on our webcam with modest exposures using the OIII filter. Focusing with such a filter is a challenge as the diffraction spike method does not work well. The narrowband filter tends to destroy the spikes! I was suprised at how bright the nebula showed. It was, in retrospect, visible in the raw frames.
Location: Curdridge, Southampton, UK. 51N 15W.
Details of equipment and method.