Simcoe Skies Astronomy

M51 - The Whirlpool Galaxy

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M51
M51
The often-imaged Whirlpool Galaxy

Magnitude: 8.0
Location: Canes Venatici (Hunting Dogs)
Date: Sept 19/04
Exposures: 19 best of 40
Exposure length: 45 seconds
Amp on setting: OFF
Brightness: 100
Gain: 20

Notes: First try at M51. Amp glow really killed it. This was with Amp off, so I figure (in retrospect) it was a dark frame subtraction issue, where my background level wasn't high enough (all pixels should have a value >0). I expected to get some amp glow in a 45 second shot, but after dark subtraction, it should have disappeared.

M51 with amp glow removed in Photoshop
Trying to get rid of amp glow
Same image, amp glow removed in Photoshop.

Details: see previous

Notes: I doctored up my first shot with Photoshop to try to eliminate some of the amp glow. It worked, to some extent. Future images should have gain increased to 40 or so and provide a minimum level on all pixels for proper dark subtraction.

M51 different processing
M51
Same AVI, another kick at the processing can...

Details: see previous

Notes: Processed differently, just for the heck of it. In some ways, it looks better! Shows the density of the galaxy better, as well as the interaction with its companion galaxy.

M51 - July 2005
Details:

Date: July 21/05
Exposures: 51 best of 80, autoguided in RA only w/70mm refractor
Exposure length: 20 seconds
Amp on setting: OFF
Brightness: 100
Gain: 40
Gamma: 52

Notes:Early experiments in guiding. I suspect that the guidescope cam was not rotated correctly, but still a decent shot. Fighting the rising moon at 85% waning, thus a longer exposure wasn't possible. Previously noted amp glow problem was solved by taking the dark frame with the cam IN the eyepiece adapter.

BONUS! Supernova SN2005CS
Details:

Date: July 21/05
Same data as previous.

Notes:I saw among some online postings that there was a new supernova reported in M51, discovered on June 28, 2005. Naturally, I checked my image from last year vs. my image from this July, and sure enough, there it was! So here's an animation from my two previous shots, to show where it's located. Amazingly bright!

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	M51 The often-imaged Whirlpool Galaxy Magnitude: 8.0 Location: Canes Venatici (Hunting Dogs) Date: Sept 19/04 Exposures: 19 best of 40 Exposure length: 45 seconds Amp on setting: OFF Brightness: 100 Gain: 20 Notes: First try at M51. Amp glow really killed it. This was with Amp off, so I figure (in retrospect) it was a dark frame subtraction issue, where my background level wasn't high enough (all pixels should have a value >0). I expected to get some amp glow in a 45 second shot, but after dark subtraction, it should have disappeared.

	Trying to get rid of amp glow Same image, amp glow removed in Photoshop. Details: see previous Notes: I doctored up my first shot with Photoshop to try to eliminate some of the amp glow. It worked, to some extent. Future images should have gain increased to 40 or so and provide a minimum level on all pixels for proper dark subtraction.

	M51 Same AVI, another kick at the processing can... Details: see previous Notes: Processed differently, just for the heck of it. In some ways, it looks better! Shows the density of the galaxy better, as well as the interaction with its companion galaxy.

	M51 - July 2005 Details: Date: July 21/05 Exposures: 51 best of 80, autoguided in RA only w/70mm refractor Exposure length: 20 seconds Amp on setting: OFF Brightness: 100 Gain: 40 Gamma: 52 Notes:Early experiments in guiding. I suspect that the guidescope cam was not rotated correctly, but still a decent shot. Fighting the rising moon at 85% waning, thus a longer exposure wasn't possible. Previously noted amp glow problem was solved by taking the dark frame with the cam IN the eyepiece adapter.

	BONUS! Supernova SN2005CS Details: Date: July 21/05 Same data as previous. Notes:I saw among some online postings that there was a new supernova reported in M51, discovered on June 28, 2005. Naturally, I checked my image from last year vs. my image from this July, and sure enough, there it was! So here's an animation from my two previous shots, to show where it's located. Amazingly bright!