LBN406 is a
very faint Reflection Nebula in Draco. Position: RA: 16h46m07s, Dec:
Camera: QHY8 without filter. Gain 20, Offset 117, No flats,
generated in PixInsight with Dynamic Background extraction, No darks.
Telescope: Celestron C14 with Hyperstar Focal Reducer. Focal length 675mm,
Focal ratio F1.9!
Mount: Gemini G41, guided with STV on ETX90.
Its very difficult to make the LBN406 nebula visible.
Without any image processing
there is nothing to see from the nebula which
was more than 5 hours in total exposed.
It needed many steps in PixInsight 1.06.
Click on the basic stacked image below to see the final version -
Hint: a nice galaxy - PGC58928 looking like Saturn - is visible
near the upper border in the middle of the processed image.
LBN406 55x6 minute Images Stacked and unprocessed:
(Click on the below image for the processed image 1600x1200.)
The Hyperstar Reducer
changes the focal length of the the
Celestron C14 from 3900mm to 675mm and a focal ratio of F1.9
Watch the special arc for guiding the cables from the QHY8 CDD camera to the
computer. The arc removes the usual
spikes introduced by running the USB cable, power cable and control cable over
the Schmidt plate of the C14.
fThe Hyperstar is
calibrated with CCDCap Image capturing Software. Calibration is easy. There is
only a very bright star needed. It will be strongly
defocused and the black circle visible in the middle of the image needs to be
precisely centered with the help of the center screws on the Hperstar.
Than fine focusing is done with the help of the focusing software Robofocus. Its
connected to my Gemini FocusR
focuser with stepper motor and absolute positioning.
The mirror is fixed than with the Mirror-Lock-Screws.
As next step the guiding scope is aligned with the C14. Than a Goto to the
selected guiding star and bringing the object into the center of the image.
Calibration of the STV on the guiding star follows. Now everything is ready for
imaging if the weather still permits.
Overview Image - LBN406 surroundings - the Draco
Captured with 300mm F2.8. Luminance Image by Dr. Franz Gruber.
homepage of Dr. Franz Gruber here.)
Exposure time 11400 Seconds with ST11K. The LBN406 is the brightest part in
the middle part of the left side.
There is a lot more nebulosity around the LBN406 which makes these area more
interesting for future imaging sessions.
(Only basic image processing was done with PixInsight on this image)