The story (and stats) behind the APOD

Yesterday’s Astronomy Picture Of the Day was a collaboration between me, Mladen Dugec, and Max Whitby.  We have been working together on an astrophotography app, and this image was part of that work.  Wolf’s Cave is not a frequently imaged area due to its faintness, but there are a variety of objects in the area that we’ve captured in this widefield.

First, the image stats:

• Exposures:
  • Luminance 25×300s
  • Red 26×300s
  • Green 24×300s
  • Blue 24×300s
  • Total exposure time:  8 hours 25 minutes
  • Taken 26th and 28th August 2019 by Max Whitby in Northumberland, UK

• Telescope: Takahashi FSQ106EDX4 (f/5 530 mm)
• Camera: SBIG STX-16803 with Astrodon Series E Gen 2 filters
• Mount: Software Bisque Paramount MyT
• Guiding: unguided (!)
• Processing: PixInsight and Photoshop by Charlie Bracken and Mladen Dugec

For such a faint set of objects, 8 hours of exposure time is on the short side, but Max’s dark skies in Northumberland, UK were a big asset.  As usual, the individual subs didn’t reveal much, but the first time I saw the initial integrated image, I knew we had something special.

So what are we looking at here?  The part known as Wolf’s Cave is in the center.  It’s cataloged as reflection nebula vdB 152 (read “van den Bergh 152”), and the long dark nebula that trails behind it is B175 (read “Barnard 175”).  Astronomer Max Wolf announced this object in 1908, describing it as a “cave-nebula” at “the end of a long starless lacuna.” Later, he goes on,

“All over the cave lies a network of still darker spots and channels. This raises the hope that we may understand the interesting process more thoroughly at some future time, when we can photograph the region in greater detail with more optical power.”

Well, Dr. Wolf, that time has clearly arrived.  If he were still alive, I’m sure he would be amazed that this could now be accomplished by non-professional astronomers with much smaller equipment (his original discovery image was taken with a 28-inch reflector).  The area is indeed dense with molecular clouds, and the densest patch in the upper right is cataloged as LDN 1221—it’s surprising that Barnard missed this one, but Beverly Lynd picked it up in his catalog later.

There is a really colorful little planetary nebula near the center called Dengel-Hartl 5. DeHt5 was not cataloged until 1980, based on the Palomar survey plates.  The big mystery for us was the thin filament of H-alpha nebulosity that runs diagonally across the image.  It could be LBN 528, but Bob Franke notes that it is part of a much larger supernova remnant called SNR 110.3+11.3, on which there is very little information.

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The Iris Nebula (NGC7023, vdB139)

This is one of those objects that I seem to have imaged several times over the years, but each time something went wrong.  Tracking issues, moon issues, dark frame issues, you name it.  So until now, I never really had a decent image of this premier object.

Two nights ago, I had a really still, moonless night.  I looked up the culmination time of the Iris Nebula: 11:30pm.  All I had to do was stay up to manage the meridian flip, and I could get 6-7 hours of good data.  And indeed, that’s what I did.  This was one of those nights where everything worked, the sky stayed completely clear, and every sub was good.

The image below represents 89x180s luminance and 10x180s each R, G, and B taken with an ASI1600MM-Pro through an FSQ106 on an EM-200 mount.  Processing was done entirely in PixInsight.  This image is half the resolution of the original to keep the size manageable.

The Moon and Old Faithful

What to do when a first quarter moon interferes with your plans to shoot the Milky Way in Yellowstone National Park?  Incorporate it into the shot!

On the one clear night I got during my trip to Yellowstone, the moon was too bright to capture the Milky Way like I’d hoped to, but I was able to walk around to the back side of Old Faithful to bring it into the shot.  This is a series of 15-second exposures at ISO1600 gain using a Rokinon 14 mm lens at f/2.8 on a Canon 6D.

Seeing a geyser at night was an beautiful experience.  It was quiet and calm, with very few people out.  If you are ever in Yellowstone, I recommend staying up late, when you’ll have Old Faithful all to yourself (and maybe a bear or two).

Custom digital editions of The Astrophotography Planner now available!

I am now able to create a custom digital edition of The Astrophotography Planner for you.  It’s the same price as the print book ($19.99), but instead, you get a custom pdf of over 160 pages with data based on your specific location. It also includes additional details like moon rise/set data incorporated into the charts and an overview chart showing how many Quality Imaging Hours are available for all 76 areas in one view.  Plus, you get charts that go an extra year beyond the print book:  2019-2021.

If this is something you are interested in, please send $19.99 via Paypal to deepskyprimer@gmail.com with:

• Your name
• Your latitude and longitude (rounded to the nearest degree is fine)
• Your time zone

Turnaround is 1-4 days, since each one requires some manual steps to create.

NEAF 2019

Now that I’m back in the states again, it’s great to be able to attend the Northeast Astronomy Forum in Suffern, NY.  There are lectures and solar observing, but for me the main attraction is the exhibit floor.  This is where you can see the scope, mount, or whatever that you’ve always wanted, in person.

All of the usual suspects were there, and it was great to catch up with people and meet a few new astro-friends.  I hadn’t been in over five years, so it was interesting to see how things have changed.  A few observations follow:

• For scopes, Celestron, Meade, and TeleVue were there with big booths, but it was great to see that Explore Scientific had a booth to match (and probably with more scopes, including some awesome refractors in the 152-165 mm range).  Takahashi had a small booth, as did William Optics.  AstroPhysics had a good size booth with lots of glass to look at.  Omegon had some scopes on display too.

• For cameras, Atik, QSI, FLI, QHY, and ZWO were all there.  QHY had examples of their high-end scientific cameras, including the much-talked-about QHY600, which he said would be priced at “over $8000” when released.  There was a medium format scientific camera that was “over $50,000” if that’s not a big enough chip for your needs!

• One hot item seemed to be Omegon’s new MiniTrack LX2, a mechanical (wind-up) travel mount for wide-field AP; like the AstroTrac, but much smaller (and cheaper, with a NEAF special price of $115).  I thought a cool innovation it had was to use adjustable tension instead of counterweights.
• There didn’t seem to be as many small vendors as I remember.  Two publishers had booths (Willman-Bell and Springer), and some software companies did too (SGP, Diffraction Limited).  It was great to see the filter manufacturers there (Chroma, Optolong)
• There were only a few retailers there, but Highpoint Scientific and Woodland Hills had lots for sale.  Some of the non-US vendors couldn’t sell direct, but were giving out coupons to use online or with the vendors on-site.

So did I find some goodies to lust after?  Absolutely.  I decided that maybe a 140 mm refractor could just be handled by my mount, and I really liked the Explore Scientific carbon fiber FPL-53 triplet they had on display.  I also found that the William Optics RedCat was a bit bigger than I expected a 51 mm to be, and not much smaller than my Star71, though the FLT132 behind it looked pretty nice.

Overall, it was great to be there and see the people of this hobby in person, rather than just online.  (Does amateur astronomy still skew white, male, and older?  Yes.  But it does seem to be getting better.)  I love that there are new manufacturers coming into the astrophotography space and shaking things up a little.  There was definitely more of a focus on AP than visual, or maybe that’s because that’s what I was looking for.  NEAF is always worth it, and 2019 was no exception.

The Dark Nebulae of NGC7000

For an incomplete project I’ve been working on, I matched up Barnard’s Atlas of Selected Regions of the Milky Way with my own widefield image of the NGC7000 area.  In case you’ve ever wondered about the designations of the dark nebulae around the North America Nebula, here they are!

I find it odd that he didn’t catalog the “Gulf of Mexico,” but when you look at his plates, what we now call the Pelican Nebula isn’t as bright, so the Gulf doesn’t look as distinct.  It was subsequently picked up in Lynd’s catalog as LDN 935.

The Astrophotography Planner is published!

I’m happy to announce that my latest book is now available.  This one started out as my personal almanac to help plan when different objects were best positioned in the sky.  I’ve expanded upon that to create a full book with maps and complete details for 76 of the most popular imaging targets. 

Producing great deep-sky images requires many hours of exposure time. Knowing when an object is optimally placed in the sky is critical to gathering the best data.

This book features charts and maps for 76 of the best deep-sky objects visible from the northern hemisphere. The charts show how many quality imaging hours you can expect for each on any given date, as well as where it will be positioned. Maps are provided to help you decide how to frame each object, and field of view templates are provided for common sensors and focal lengths. Detailed information about the moon is included for 2019 and 2020.

In short, The Astrophotography Planner will help you make the most of every clear night to produce the best deep-sky images possible.

Buy it on Amazon.

A sample page is posted below.  There are 76 areas of the sky covered exactly like this in the book. Instead of simple rise and set times, it shows when the object is at least 15º above the horizon and the sky is dark.  Separate lines are plotted for those at 30º, 40º, and 50º latitude.

Available on Amazon.

Areas of the sky covered:

• Sh2-308
• The Seagull Nebula
• Thor’s Helmet
• Medusa Nebula
• Abell 31
• NGC2903
• M81 and M82
• The Hickson 44 Galaxy Group
• NGC3521
• The Leo Trio
• M109
• The Antennae Galaxies
• M106
• Markarian’s Chain
• The Needle Galaxy (NGC4565)
• The Sombrero Galaxy (M104)
• The Whale and Hockey Stick Galaxies
• The Sunflower Galaxy (M63)
• The Whirlpool Galaxy (M51)
• M3
• The Pinwheel Galaxy (M101)
• NGC5907
• M5
• The Draco Trio
• The Rho Ophiuchi Area
• The Great Hercules Cluster (M13)
• The Snake and Pipe Dark Nebulae
• The Trifid Nebula
• The Lagoon Nebula (M8)
• The Eagle and Swan Nebulae (M16 and M17)
• M22
• Barnard’s E
• Sh2-86
• The Tulip Nebula (Sh2-101)
• The Dumbbell Nebula(M27)
• The Crescent Nebula
• The Propeller Nebula
• The Gamma Cygni (Sadr) Nebula
• The Fireworks Galaxy (NGC6946)
• The Cygnus Veils
• The North America and Pelican Nebulae
• The Iris Nebula
• Sh2-129
• The Elephant’s Trunk (IC1396)
• The Cocoon Nebula
• The Wolf’s Cave (vdB 152 and B175)
• Sh2-132
• The Helix Nebula
• NGC7331, the Deer Lick Group, and Stephan’s Quintet
• The Wizard Nebula (NGC7380)
• The Bubble and the Lobster Claw
• Ced214 and Sh2-171
• The Andromeda Galaxy (M31)
• The Sculptor Galaxy (NGC253)
• The Pacman Nebula (NGC281)
• The Ghosts of Cassiopeia (IC59 and 63)
• The Triangulum Galaxy (M33)
• NGC891
• The Heart and Soul Nebulae
• NGC1333
• IC342
• The Pleiades
• The California Nebula (NGC1499)
• Sh2-206
• The Witch’s Head Nebula
• The Flaming Star, the Spider, and the Fly
• The Crab Nebula
• The Orion and Running Man Nebulae
• The Horsehead, Flame, and M78 Nebulae
• Barnard’s Loop
• Simeis 147
• NGC2170
• Lower’s Nebula (Sh2-261)
• The Jellyfish and Monkey’s Head Nebulae
• The Rosette Nebula
• The Cone, Foxfur, Christmas Tree Area