Archive for March, 2011

Monkey Nebula (NGC 2174) with SVR90T in Narrow band

Location: San Bruno, CA

Telescope: Stellarvue SVR 90T with Stellarvue Field flattener  on Takahashi NJP-Z Mount

Camera: Qhy9 CCD with Astronomik H-Alpha 12nm Filter and O-III 12nm Filter

The color picture is a “HOO” Narrowband picture:

  • H-Alpha: red channel – 16 exposures of 480secs.
  • O-III:   green and blue channel – 21 exposures of 480 secs.

On the left, the H-Alpha image, on the right the HOO composite image. Note the Monkey nebula emits mainly in H-Alpha only the central parts of the nebula glows in the OIII band.

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Saturn “Serpent Storm” with Celestron EdgeHD 11″

Date: 2/27/2011 at 2.23am PST

Location: San Bruno California

Telescope: EdgeHD 11 with DMK 21AU04.AS Camera and Siebert Barlow 2x

Seeing: 6/10

Image Processing: Frame stacking: AVI Stack, Image composition: Photoshop CS4, Astra Image Wavelet plug-in, Noise Ninja

This is one of the first pictures taken with my new Celestron EdgeHD 11″.  The seeing was  above average – but not excellent. Visually at x450, Saturn was impressive, with a great contrast on the Cassini division, and details easily visible on the north band (the great north band disturbance famously called “serpent storm”).

The 11″ of aperture here made a huge difference with previous images taken with my Mak Cassegrain 7″, not so much in terms of pure resolution (limited by seeing) – but in terms of image brightness. I imaged at f/d 25 – I should have imaged at f/d 37 with the Mak Cassegrain to achieve the same image scale. I was able to take most of the frames at 1/10 sec. or below, to capture moments of best seeing. This is a composite image made of roughly 2,500 frames shot in about 6 minutes.  Capturing Saturn’s satellites up to magnitude 12 on the luminance frame was fairly easy – even though each frame was 1/20sec of exposure for the luminance layer.

Saturn satellites from left to right:

  • Dione : magnitude 10.5
  • Enceladus: magnitude 11.9
  • Rhea: magnitude 9.9
  • Thetys: magnitude 10.4

This is a set of three images taken during this imaging session  showing Saturn’s rotation…

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