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Posts Tagged ‘sii’

The Heart Nebula, IC1805, in Narrowband

January 27, 2015 Leave a comment

This is one of my favorite deep sky objects, especially for narrowband.  It just fits on an KAF-8300 chip at 350 mm focal length.  The small cluster in the core is Melotte 15.

I took three nights of exposures, which were spread over 41 days due to poor weather and holiday trips.  Maybe next year when Cassiopeia swings into view, I’ll make a similar project of the Soul Nebula nearby.

The Heart Nebula (IC1805)

The Heart Nebula (IC1805)

Image data:

  • Exposures: 32 hours total: 96 x 10 min Ha, 43 x 10 min OIII, 53 x 10 min SII
  • Telescopes: Two William Optics Star 71s (360mm f/5)
  • Cameras: SBIG ST-8300M and QSI 583wsg, 2×2 binned
  • Mount: CGEM
  • Guiding: QHY 5L-II mono, guided using PHD2
  • Conditions:  mild winds on two nights
  • Processing: DeepSkyStacker -> PixInsight -> Photoshop
  • Date: Nov 21 2014, Dec 31 2014, and Jan 1 2015
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The Bubble and the Lobster Claw

January 10, 2015 Leave a comment

There is an area on the border of Cassiopeia and Cephus that’s packed with deep-sky objects, including the assortment shown here.  The main nebula here is the Lobster Claw, Sh2-157.  Above it and to the right is the famous Bubble Nebula, NGC7635. In the upper right is the cluster M52.  The nebulae at middle right and lower right are Sh2-159 and NGC7538, respectively.  The very dim nebula the goes off the right edge of the image is Sh2-161, and the little star cluster at middle bottom is NGC7510. So that’s at least five distinct nebulae and two star clusters (there would be more if we considered how other catalogs, like the LBN and IC, define the objects).

The Bubble and Lobster Claw NebulaeWith all of that said, this is the second year I’ve imaged this area, and I haven’t been happy with either result.  The Lobster Claw is not particularly photogenic, and it’s fairly hard to process well.  Given the chance to do it again, I’d probably either use a longer scope to focus on the Bubble Nebula alone, or go even wider with a telephoto to capture the sea of nebulosity in the whole area.

Image data:

  • Exposures: 60 x 10 min Ha, 33 x 10 min OIII, 27 x 10 min SII
  • Telescopes: Two William Optics Star 71s (360mm f/5)
  • Cameras: SBIG ST-8300M and QSI 583wsg, 2×2 binned
  • Mount: CGEM
  • Guiding: QHY 5L-II mono, guided using PHD2
  • Conditions:  strong wind gusts
  • Processing: DeepSkyStacker -> PixInsight -> Photoshop
  • Date: Nov 18 and 20, 2014

The Cave Nebula (Sh2-155)

November 22, 2014 Leave a comment

The Cave Nebula is probably better suited for 600 mm of focal length, but I thought I’d try a wide field view of the area.  The whole nebula is fainter than I expected, especially the diffuse OIII spread about the region.  20- or 30-minute sub-exposures would do a much better job of revealing it, but because it was so windy, I wanted to keep the subs at 10 minutes, so I really had to fight a lot of noise in the blue channel.

The Cave Nebula (Sh2-155) in narrowband SHO palette

The Cave Nebula (Sh2-155) in narrowband SHO palette

Image data:

  • Exposures: 55 x 10 min Ha, 28 x 10 min OIII, 28 x 10 min SII
  • Telescopes: Two William Optics Star 71s (360mm f/5)
  • Cameras: SBIG ST-8300M and QSI 583wsg, 2×2 binned
  • Mount: CGEM
  • Guiding: QHY 5L-II mono, guided using PHD2
  • Conditions:  gusting winds
  • Processing: DeepSkyStacker -> PixInsight -> Photoshop
  • Date: Nov 9-10, 2014

NGC7000

November 18, 2014 Leave a comment

This is not exactly a shining moment as an astroimager, because I completely messed up the polar alignment routine, resulting in smeared stars.  (When the CGEM tells you not to pick polar alignment stars too close to the pole, it means it!)  But NGC7000, more commonly known as the North America Nebula, is such a compelling object, I’m posting the image anyway.  It also gives a sense of how wide the field of view on the Star 71 is.

NGC7000 "The North America Nebula" in Narrowband

NGC7000 “The North America Nebula” in Narrowband

Image data:

  • Exposures: 34 x 10 min Ha, 14 x 10 min OIII, 17 x 10 min SII
  • Telescopes: Two William Optics Star 71s (360mm f/5)
  • Cameras: SBIG ST-8300M and QSI 583wsg, 2×2 binned
  • Mount: CGEM
  • Guiding: QHY 5L-II mono, guided using PHD2
  • Conditions:  wind gusts over 20 mph, gibbous moon
  • Processing: DeepSkyStacker, PixInsight, Photoshop
  • Date: Nov 2, 2014

Sh2-132 in Narrowband

November 7, 2014 3 comments

Both of my WO Star 71s are back from China (see previous post), cleaned, and as good as new.  Maybe better.  It took a few days after their return for some clear weather to arrive, but I was so happy to have them back.  William Yang was a good guy to deal with in this whole matter.

Sh2-132 is an odd nebula in that it can be hard to find.  Not so much because it’s not a reasonably bright narrowband target, but because it has no appeal to visual observers, so it’s not well-marked in most atlases.  Not all of the Sharpless objects are worthy targets (in fact the majority are duds), so it can be hard to tell that this one stands out from the emission nebula crowd.

It’s a photogenic target in the Hubble/SHO palette if you can take enough exposures to reveal the details, and several amateur images of it have popped up this season.  The SII is particularly dim, and if I could do it again, I would double the exposure time there.

Sh2-132 in the Hubble/SHO Narrowband Palette

Sh2-132 in the Hubble/SHO Narrowband Palette

Image data:

  • Exposures: 42 x 10 min Ha, 41 x 10 min OIII, 43 x 10 min SII
  • Telescopes: Two William Optics Star 71s (360mm f/5)
  • Cameras: SBIG ST-8300M and QSI 583wsg, 2×2 binned
  • Mount: CGEM
  • Guiding: QHY 5L-II mono, guided using PHD2
  • Conditions:  wind gusts over 25 mph… far from ideal
  • Processing: DeepSkyStacker, PixInsight, Photoshop
  • Dates: Oct 25-27, 2014

The Rosette Nebula in Narrowband

February 10, 2012 Leave a comment

This is my second narrowband image, and the debut of my new Borg 77EDII.  The best thing about this image is that it was gathered over three nights when the moon was over 85% full.  I could never have done that before moving to narrowband!

It could definitely use more S-II data, but I’m pleased with this first attempt.  I didn’t realize how dim the S-II portions of the Rosette would be, otherwise I would have used more of the total exposure time there.

This image is processed in a modified version of the teal-gold motif that Bob Franke describes on his website (http://bf-astro.com/hubbleP.htm).

The Rosette Nebula in Narrowband

Image data:

Exposures:  28 x 600s Ha, 20 x 600s O-III, 20 x 600s S-II

Software:  guiding by PHD, stacking in DeepSkyStacker, processing in Photoshop CS3

Telescope:  Borg 77EDII w/ f/4.3 reducer

Camera:  SBIG ST-8300M with Baader narrowband filters

Mount:  CGEM

M42 Orion Nebula in Narrowband

February 5, 2012 1 comment

Some weeks, everything goes wrong.

To quench the never-ending thirst for more concentrated photons, I sold my previous scopes so I could trade up to two high-end, fast refractors:  a Borg 77EDII at f/4.3 and a TeleVue NP101 at f/5.3.  I seized rare opportunities to get both used and at great prices.  Only if a Tak FSQ came my way would I have room to improve in the short focal length department.  But with all new scopes come new problems.  The NP101 needed rings to sit on my mount, and an adapter for my stepper motor to control the focuser — $200 and two weeks.  The Borg needed precise spacers to fit my camera, and I’m still working out other kinks — $100 and at least two weeks.

Now I find out that my SBIG’s cooling is not functioning correctly, so basically every piece of imaging equipment I have is “in the shop,” in one way or another.  But sometimes even with adversity, something fun or beautiful slips through.  I took the NP101 out on a hazy, moonlit night because I really wanted to start working with narrowband data.  The obvious, reliable target sat just above my roof:  M42.

The world needs another image of M42 like a hole in the head, but I couldn’t resist.  Before it set, I grabbed two hours of narrowband exposures, and here is my very first narrowband image:

Stats:  SBIG ST8300M, Baader filters, TeleVue NP101 on a CGEM

6x300s H-alpha, 10x300s O-III, 12x300s S-II, 25 flats, NO darks

Stacked in DSS, process in Photoshop CS3.

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