Simcoe Skies Astronomy

M101 - The Pinwheel Galaxy: 27 Million light years distant, in Ursa Major

To read more about this object on wikipedia, click here.

M101 image, using Meade DSI-2 (color)
M101 with Meade DSI-2C imager

Date: July 2/05
Exposures: 44
Exposure length: 45 seconds
Gain: 63(full)
Offset: 0
Filters: Camera filter (IR) only
Guided in RA
Flat frame applied, post-processing with Photoshop

Notes: Guiding was a real benefit to this image, and with the larger field of view of this camera, the majority of the galaxy is visible. Using a 16-bit camera made a significant difference in the amount of detail.

M101, July 2005
Processed with less brightness

Date: July 2/05
Exposures: 62
Exposure length: 19 seconds
Amp on setting: OFF
Brightness: 100
Gain: 50
Notes: First experiments with guiding on this one, amp glow problem solved! "Holes" in image due to hot pixel removal in K3CCDtools. Amp glow was previously showing up because I was removing the cam from the eyepiece adapter for dark frames. This changed the temperature for the dark and created a mismatch.

M101
M101 - Sept/04 (first attempt)
This is a partial shot

Date: Sept 18/04
Exposures: 33 best of 61
Exposure length: 20 seconds
Amp on setting: OFF
Brightness: 100
Gain: 50
Notes: This is a BIG sucker! Image appears "noisy" because it's a high light level area (center core) of a large galaxy. Mental note to try this again with a focal reducer, eyepiece projection, or make a mosaic and get the whole thing. Reducing the gain may help to emphasize the spiral structure vs. overall brightness.

M101
M101, reduced image size
1/3 size image to illustrate better contrast overall

Date: Sept 18/04
Exposures: 33 best of 61
Exposure length: 20 seconds
Amp on setting: OFF
Brightness: 100
Gain: 50
Notes: This looks better - thus either eyepiece projection or a focal reducer would compress the image and increase the contrast (and reduce the exposure length required).

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	M101 with Meade DSI-2C imager Date: July 2/05 Exposures: 44 Exposure length: 45 seconds Gain: 63(full) Offset: 0 Filters: Camera filter (IR) only Guided in RA Flat frame applied, post-processing with Photoshop Notes: Guiding was a real benefit to this image, and with the larger field of view of this camera, the majority of the galaxy is visible. Using a 16-bit camera made a significant difference in the amount of detail.

	M101, July 2005 Processed with less brightness Date: July 2/05 Exposures: 62 Exposure length: 19 seconds Amp on setting: OFF Brightness: 100 Gain: 50 Notes: First experiments with guiding on this one, amp glow problem solved! "Holes" in image due to hot pixel removal in K3CCDtools. Amp glow was previously showing up because I was removing the cam from the eyepiece adapter for dark frames. This changed the temperature for the dark and created a mismatch.

	M101 - Sept/04 (first attempt) This is a partial shot Date: Sept 18/04 Exposures: 33 best of 61 Exposure length: 20 seconds Amp on setting: OFF Brightness: 100 Gain: 50 Notes: This is a BIG sucker! Image appears "noisy" because it's a high light level area (center core) of a large galaxy. Mental note to try this again with a focal reducer, eyepiece projection, or make a mosaic and get the whole thing. Reducing the gain may help to emphasize the spiral structure vs. overall brightness.

	M101, reduced image size 1/3 size image to illustrate better contrast overall Date: Sept 18/04 Exposures: 33 best of 61 Exposure length: 20 seconds Amp on setting: OFF Brightness: 100 Gain: 50 Notes: This looks better - thus either eyepiece projection or a focal reducer would compress the image and increase the contrast (and reduce the exposure length required).