• LBN 553 in Cepheus
  • LBN 553 in Cepheus, a bright nebula
    LBN553 Annotated
    Usually, these descriptions are short, but I've decided to wax loquacious in this one.  When searching for cool objects to photograph, LBN 553 showed up on Sky Safari as a medium to small object with no picture available.  Now, LBN stands for Lynds' Bright Nebula (after Beverly Lynds, one of the more famous female astronomers) and the description reads, "LBN 553 is a Bright Nebula appearing in the constellation Cepheus."  At this point, I'm thinking, "Whew, so glad we could contribute that supplemental information."  The description does add that the size is roughly 5' × 5', but with no picture or further information, the prospects here seemed pretty slim.
    On the other hand, I have seen a few wide field of views of Cepheus (greater than 1.5° x 1.0°) that show this region of the sky is packed with interstellar gas and molecular clouds.  This prompted me to do a mini-sky survey just to see what other fun things might show up in photos of Cepheus.  If you hover or mouseover the picture, you will see 24 stars bright enough to make it into the Hipparchos catalog, 10 PGC, Principal Galaxies Catalogue, objects of which only two are too small for me to identify visually, 2 Lynds' Bright Nebulae, and 1 Lynds' Dark Nebula.
    Please remember that Beverly Turner Lynds was working off red and blue plates from Palomar's Sky Survey 1 in the 1960s.  She carefully traced the oulines of the objects she identified and recorded their positions using 1950 coordinates.  The annotation program I use makes ellipses to identify these positions, so it's not very easy to identify exactly what Beverly saw and traced.  The only Lynds' object that seems to match these annotations is LBN 567, and even then, the circle used here seems a bit small.  In the first 300 second frame from 6 September, 2026, nothing showed at the position of LBN 553.  The dark area at RA 22h and Dec +76° 30' did show so I recentered that left-to-right in the frame.
    At any rate, this impromptu sky survey shows three areas that I find interesting.  The first is that large dark area at 22h and +76° 30'.  Even more interesting is the smaller dark nebula at 21h 33m and +76° 33'.  Most interesting of all is the triplet of dark nebulae at 22h 3m and +75° 50'.  Alas, too many pictures, not enough dark night skies.
  • Hover over the picture for an annotated version
  • Date:  6 September 2026
  • FOV:  a bit less than 4.5° × 3.0°
  • Rotation:  179.996°
  • Telescope:  Askar FRA300 (nominally 300mm, f/5
  • calculated 298.74mm, f/4.979)
  • Guiding:  ZWO ASI120MM mini mono guide cameras,
  • SVBony SV165 Mini 40mm f/4 guide scopes
  • Computer:  ASIair plus
  • Mount:  ZWO AM5 harmonic drive
  • Cameras:  ZWO ASI2600mc Pro (-10°C) at 100 gain
  • Pixel size:  3.76 μm
  • Resolution:  2.596 arcsec/pixel
  • Stacking:  eighty two 300 second frames using Pixinsight
  • Total Time:  6 hours 50 minutes
  • Processing:  Pixinsight
  • MGC, DBE, SPCC, BXT, NXT → Linear
  • Linear:  MultiAdaptiveStretch → Stars
  • HTS, GHS, MStr, and MAS run on Linear
  • PixelMath 0.25*(HTS + GHS + MStr + MAS),
  • CurvesTransformation, HDRMST6PhLm → Starless
  • PixelMath ~(~Stars*~Starless), DynCrop/Scale
  • Location:  Darling Hill Obseratory near Vesper, NY