Home > Uncategorized > The story (and stats) behind the APOD

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.

Wolfs Cave Submission CBMDMW

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.

Categories: Uncategorized
  1. No comments yet.
  1. No trackbacks yet.

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

%d bloggers like this: