SaratogaSkies Jim Solomon's Astropics

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C/2004 Q2 [Machholz] (Comet)

Image Details:

Camera: Canon Digital Rebel (300D)
Mount: Celestron AS-GT
Scope: Orion ED80 (80mm f/7.5 APO Refractor)
Configuration: Focal Reduced
Additional Optics: Celestron F/6.3 Reducer/Corrector (0.63x)
Filter: None
Effective Focal Length: 420mm
Effective Focal Ratio: f/5.2
Exposure: 65 x 2min @ ISO 800
Total Exposure: 2hrs, 10min
Date: 2/1/2005 7:24:34 PM (start)
Location: Saratoga, CA, USA
Acquisition: DSLRfocus
Focus: DSLRFocus
Dithering: None
Guiding: GuideDog via Philips ToUcam Pro II (840k) through Orion ST80 w/ Celestron 2x "Kit" Barlow

Processing:

  • IRIS: Dark subtraction, flat field, registration, cropping
  • JimP: N through M stacking, sequence ASINH stretching
  • Photoshop: Compositing, levels, image scale, JPG conversion
  • Premiere: AVI creation from individual frames

Image Description:

This is my second attempt at Comet C/2004 Q2 (Machholz), named after the San Jose Astronomical Association (SJAA) member Don Machholz who discovered it. See the ST80 image for a description of the processing steps and for a comparison picture. Perhaps the best-resolved object in this picture is Trumpler 3, the small Open Cluster of stars in the lower left (above the copyright notice).

To process this image, I used the technique described in this thread in the CloudyNights Forum. The difference is that I did all the machinations after ASINH stretching each individual frame, whereas I believe the author worked on the linear frames and only stretched the final result.

I had some major problems with the capture of this image:

  1. The ED80 was severely out of collimation when this was shot.
  2. The ED80 with Celestron f/6.3 Reducer has some field flatness issues, causing aberrations beyond the center of the frame. The collimation problem mentioned above exacerbates this.
  3. The framing of the comet, while asthetic in that there's "room" for both the ion and debris tails, places most of the interesting detail outside the "sweet spot" of the ED80 + focal reducer, making the signal to noise of the ion tail (in particular) quite low.
  4. There was tons of light pollution to the NorthWest, the direction this was shot on that night.
  5. My polar alignment was less than marvelous, causing roughly 0.5? of field rotation over the course of the imaging session. While IRIS is quite capable of derotating the frames, part of me believes that this function causes a loss of detail and an overall decrease in signal to noise.
  6. The comet was actually moving twice as fast (in arc-seconds per minute) than predicted by The Sky software. Had I known this, I might have gone for even shorter integrations (1min) at higher ISO (1600), since that would have been less than a pixel's worth of movement over the course of each frame, theoretically resulting in less blurring of each individual frame since I was guiding on a star, not the comet.
  7. The transparency that night was pretty awful.

So, that's my sob story, and all of the above show in the (lack of) detail in this image. Sniff. The movie (1MB AVI) is pretty cool and worth checking out. North is up.

 
M64 (Black Eye Galaxy)
SaratogaSkies Jim Solomon's Astropics

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M64 (Black Eye Galaxy)

Mouse-over to see annotations. (Requires Javascript) Click to see high-res version.

Image Details:

Camera: Mofidied Canon Rebel XT (350D): Hutech Type I Filter Replacement
Mount: Celestron AS-GT
Scope: Celestron C8-N (8" f/5 Newtonian)
Configuration: Prime Focus
Additional Optics: Celestron/Baader Multi Purpose Coma Corrector (MPCC)
Filter: None
Effective Focal Length: 1000mm
Effective Focal Ratio: f/5
Exposure: 32 x 8min @ ISO 400
Total Exposure: 4hrs, 16min
Date: 5/17/2007 9:38:43 PM PDT (Start)
Location: Saratoga, CA, USA
Acquisition: DSLRfocus
Focus: DSLRFocus
Dithering: GADFly 1.0.5
Guiding: GuideDog via Philips ToUcam Pro II (840k) through Orion ST80 w/ Celestron 2x "Kit" Barlow

Processing:

  • IRIS: Dark subtraction, registration, gradient removal
  • JimP: Flat field, Kappa-Sigma Stacking, White balance, ASINH stretching
  • Photoshop: Sharpening, cropping, JPG conversion

Image Description:

This is M64, aka, the “Black Eye Galaxy”, a spiral seyfert galaxy in the constellation of Coma Berenices. Seyfert galaxies have an active galactic nucleus containing a supermassive black hole. A higher resolution image is also available. North is up.

 
Milky Way (Summer Triangle)
SaratogaSkies Jim Solomon's Astropics

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December: Test shots with new scopes/mounts

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Milky Way (Summer Triangle)

Mouse-over to see annotations. (Requires Javascript) Click to see high-res version.

Image Details:

Camera: Mofidied Canon Rebel XT (350D): Hutech Type I Filter Replacement
Mount: Celestron AS-GT
Scope: Canon EF 14mm f/2.8L USM lens
Configuration: Prime Focus
Additional Optics: n/a (Prime)
Filter: None
Effective Focal Length: 14mm
Effective Focal Ratio: f/2.8
Exposure: 35 x 4min @ ISO 200
Total Exposure: 2hrs, 20min
Date: 7/31/2006 11:00:06 PM PDT (start)
Location: Saratoga, CA, USA
Acquisition: DSLRfocus
Focus: DSLRFocus
Dithering: Manual
Guiding: GuideDog via Philips ToUcam Pro II (840k) through Orion ST80 w/ Celestron 2x "Kit" Barlow

Processing:

  • IRIS: Dark subtraction, registration, gradient removal
  • JimP: Flat field, Kappa-Sigma Stacking, White balance, ASINH stretching
  • Photoshop: Levels, cropping, JPG conversion
  • PTAssembler: Panorama creation

Image Description:

This is the second in my series of ultra-widefield images of the Milky Way. This is the so-called “next frame to the left” from the shot of the Milky Way core. This one is centered, almost, on the “Summer Triangle”, formed by the bright stars Altair, Vega, and Deneb.

For more information about this image, check out my Milky Way (Core) image which was taken with the same 14mm lens. This one, however, was taken from my house in Saratoga, CA, and there was no need to mask out the horizon when stacking the frames. Also check out the panorama containing these two images

Mouse over the image to see constellation outlines and some other annotations. The image is oriented along the galactic plane, which is to say, the Milky Way's North Galactic Pole is up. Earth's North is inclined at roughly 27° with respect to the galactic plane (63° with respect to the North Galactic Pole), as can be seen by the direction arrows in the mouse-over. A higher resolution image is also available.