Celestial hemisphere:  Northern  ·  Constellation: Canes Venatici (CVn)  ·  Contains:  IC 4263  ·  IC 4278  ·  M 51  ·  NGC 5169  ·  NGC 5173  ·  NGC 5194  ·  NGC 5195  ·  NGC 5198  ·  Whirlpool Galaxy
M51 - The Whirlpool Galaxy in HaLRGB, Cosgrove's Cosmos (Patrick Cosgrove)
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M51 - The Whirlpool Galaxy in HaLRGB

M51 - The Whirlpool Galaxy in HaLRGB, Cosgrove's Cosmos (Patrick Cosgrove)
Powered byPixInsight

M51 - The Whirlpool Galaxy in HaLRGB

Equipment

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Acquisition details

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Description

Fortunately, we had three "clear" nights around the new moon this month. I say "Clear" because the skies had no clouds, but it was hot and humid and the sky transparency was not at all great! But if you have no clouds and no moon - you collect photons!

This time of year is a little tough in that the nights are also mighty short. I really could not start capture until 11pm and I had to shut down shortly after 3am.

This clearly reduces productivity!

On the other hand, I recently got my portable Astrophoto rig up and running, so I had 3 platforms capturing 3 targets at the same time! That's a first for me!

Three times the capture! (or… three times the likelihood of really screwing things up!)

This is the first image to come from that session. This was shot with my with my Astro-Physics 130mm OTA sporting an ASI2600MM-Pro camera and this is the second target have tried with that combination.

My first attempt at capturing M51 was done almost one year ago with an OSC camera and I captured about 70 minutes of data.

This time around I was able to capture on the nights of June 4th, 5th, and 6th and ended up with just short of 10 hours of data.

I collected Luminance, and RGB data, but I also collected some shots through my narrowband Ha filter. I then created two versions of this image. In this version, folded in the Ha data - which provides the red blobs and highlight along the spiral structure of the Galaxy. These are regions of intense new star formation.

I'm reasonably happy with the result - the Ha filter data lends some better structure to the arms of the galaxy and the mistiness of the companion galaxy looks to me like a big thumps-up emoticon!

I continue to be impressed with this new camera - however I did find that the 2600 cooler could not handle the hotter weather and could not get down to -15C as I desired. (note my two other ASI1600MM-Pros) had no trouble doing this). I assume the larger format APC-C sensor just generates that much more heat when operating. So I ended up running them at -10C.

Here is some background on M51 from Wikipedia:

The Whirlpool Galaxy, also known as Messier 51a, M51a, and NGC 5194, is an interacting grand-design spiral galaxy with a Seyfert 2 active galactic nucleus. It lies in the constellation Canes Venatici, and was the first galaxy to be classified as a spiral galaxy. Its distance is estimated to be 31 million light-years away from Earth.

….

What later became known as the Whirlpool Galaxy was discovered on October 13, 1773, by Charles Messier while hunting for objects that could confuse comet hunters, and was designated in Messier's catalogue as M51.Fortunately, we had three "clear" nights around the new moon this month. I say "Clear" because the skies had no clouds, but it was hot and humid and the sky transparency was not at all great! But if you have no clouds and no moon - you collect photons!

This time of year is a little tough in that the nights are also mighty short. I really could not start capture until 11pm and I had to shut down shortly after 3am.

This clearly reduces productivity!

On the other hand, I recently got my portable Astrophoto rig up and running, so I had 3 platforms capturing 3 targets at the same time! That's a first for me!

Three times the capture! (or… three times the likelihood of really screwing things up!)

This is the first image to come from that session. This was shot with my with my Astro-Physics 130mm OTA sporting an ASI2600MM-Pro camera and this is the second target have tried with that combination.

My first attempt at capturing M51 was done almost one year ago with an OSC camera and I captured about 70 minutes of data.

This time around I was able to capture on the nights of June 4th, 5th, and 6th and ended up with just short of 10 hours of data.

I collected Luminance, and RGB data, but I also collected some shots through my narrowband Ha filter. I then created two versions of this image. In this version, folded in the Ha data - which provides the red blobs and highlight along the spiral structure of the Galaxy. These are regions of intense new star formation.

I'm reasonably happy with the result - the Ha filter data lends some better structure to the arms of the galaxy and the mistiness of the companion galaxy looks to me like a big thumps-up emoticon!

I continue to be impressed with this new camera - however I did find that the 2600 cooler could not handle the hotter weather and could not get down to -15C as I desired. (note my two other ASI1600MM-Pros) had no trouble doing this). I assume the larger format APC-C sensor just generates that much more heat when operating. So I ended up running them at -10C.

Here is some background on M51 from Wikipedia:

The Whirlpool Galaxy, also known as Messier 51a, M51a, and NGC 5194, is an interacting grand-design spiral galaxy with a Seyfert 2 active galactic nucleus. It lies in the constellation Canes Venatici, and was the first galaxy to be classified as a spiral galaxy. Its distance is estimated to be 31 million light-years away from Earth.

….

What later became known as the Whirlpool Galaxy was discovered on October 13, 1773, by Charles Messier while hunting for objects that could confuse comet hunters, and was designated in Messier's catalogue as M51.[ Its companion galaxy, NGC 5195, was discovered in 1781 by Pierre Méchain, although it was not known whether it was interacting or merely another galaxy passing at a distance. In 1845, William Parsons, 3rd Earl of Rosse, employing a 72-inch (1.8 m) reflecting telescope at Birr Castle, Ireland, found that the Whirlpool possessed a spiral structure, the first "nebula" to be known to have one.[ These "spiral nebulae" were not recognized as galaxies until Edwin Hubble was able to observe Cepheid variables in some of these spiral nebulae, which provided evidence that they were so far away that they must be entirely separate galaxies even though they are seen close together.

I always thought this galaxy had a pretty cool history - it really helped us to understand the scope of the known universe….

Thanks for looking!

Pat

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Here are the details for this image:

*Number of frames is after bad or questionable frames were culled.

67 x 90 seconds, bin 1x1 @ -15C, unity gain, ZWO Gen II L Filter

77 x 90 seconds, bin 1x1 @ -15C, 0 gain, ZWO Gen II R Filter

63 x 90 seconds, bin 1x1 @ -15C, unity gain, ZWO Gen II G Filter

62 x 90 seconds, bin 1x1 @ -15C, unity gain, ZWO Gen II B Filter

11 x 300 seconds, bin 1x1 @ -15C, unity gain, Astronomiks 6nm Ha Filter

Total of 9.9 hours

30 Darks at 300 seconds, bin 1x1, -10C, gain 100

30 Darks at 90 seconds, bin 1x1, -10C, gain 0

30 Dark Flats at Flat exposure times, bin 1x1, -15C, gain 0

Flats done separately for each evening to account for camera rotator variances:

30 L Flats

30 R Flats

30 G Flats

30 B Flats

30 Ha Flats

Capture Hardware:

Scope: Astrophysics 130mm Starfire F/8.35 APO refractor

Guide Scope: Televue 76mm Doublet

Camera: ZWO AS2600mm-pro with ZWO 7x36 Filter wheel with ZWO LRGB filter set,

and Astronomiks 6nm Narrowband filter set

Guide Camera: ZWO ASI290Mini

Focus Motor: Pegasus Astro Focus Cube 2

Camera Rotator: Pegasus Astro Falcon

Mount: Ioptron CEM60

Polar Alignment: Polemaster camera

Software:

Capture Software: PHD2 Guider, Sequence Generator Pro controller

Image Processing: Pixinsight, Photoshop - assisted by Coffee, extensive processing indecision and second guessing, editor regret and much swearing…..

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M51 - The Whirlpool Galaxy in HaLRGB, Cosgrove's Cosmos (Patrick Cosgrove)