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Posts Tagged ‘Sh2’

The Astrophotography Sky Atlas

November 22, 2015 Leave a comment

TASA Cover 500px

The Astrophotography Sky Atlas is now available at Amazon!

I spent two years coding, researching, and writing this book with a simple goal:  to create a compact, reasonably-priced atlas designed for the imager. Over 2000 deep-sky objects are plotted in their correct size and shape, including many faint nebulae not shown in other atlases. Stars are shown down to 9th magnitude.  The entire sky is covered in 70 full-color charts.

A tabular index contains important details on each object, including a description, the best time of year to capture it, and the required field of view.

What’s shown:

  • 416 emission nebulae and supernova remnants, including the complete Sharpless (Sh2) and RCW catalogs.
  • 171 reflection nebulae, including the complete van den Bergh (vdB) catalog.
  • 146 planetary nebulae, including the complete Abell catalog
  • 52 dark nebulae and molecular clouds
  • 792 galaxies (larger than 3 arcminutes)
  • 38 galaxy groups from the Abell and Hickson catalogs
  • 108 globular clusters (larger than 5 arcminutes)
  • 309 open clusters (larger than 5 arcminutes)

Keeping a focus on what is important to imaging, sparse open clusters and galaxies smaller than 3 arcminutes (unless part of a group) were left off the maps.

With information on nearly every possible photographic object in the night sky, The Astrophotography Sky Atlas will help you choose your targets and plan your imaging.

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

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

Sh2-129, The Flying Bat Nebula

September 28, 2013 Leave a comment

This is another monochromatic image I captured while the moon was near full this month. Sh2-129 is a very dim, but very large H-alpha region at the bottom of Cepheus. It’s close to the far brighter and more famous IC1396, which explains why it is so often overlooked among the sea of emission nebulae in that area. I’ve seen it referred to as the Flying Bat Nebula, but it probably has more claim to be a “Tulip” nebula than Sh2-101. This is definitely a challenging object to capture.

Nicola Montecchiari recently captured a terrific image of this nebula with the OIII-emitting planetary nebula OU4 at its core.  Looks like I will have to go back and capture some OIII data here soon!

Sh2-129, The Flying Bat Nebula, H-alpha

Sh2-129, The Flying Bat Nebula, H-alpha

Image data:
Exposures: 19 x 1200s Ha exposures
Software: guiding by PHD, stacking in DeepSkyStacker
Processing: PixInsight
Telescope: Takahashi FSQ-106ED (530 mm f/5)
Camera: SBIG STL-11000M with Astrodon 6nm narrowband filters, 2×2 binned
Mount: CGEM
September 15, 2013

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