Hemisphere:  Northern  ·  Constellation: Ursa Major (UMa)  ·  Contains:  M 108  ·  M 97  ·  NGC 3556  ·  NGC 3587  ·  NGC 3594  ·  Owl Nebula
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The Owl and The Surfboard, 


            Steven Bellavia
The Owl and The Surfboard
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The Owl and The Surfboard

Getting plate-solving status, please wait...
The Owl and The Surfboard, 


            Steven Bellavia
The Owl and The Surfboard
Powered byPixInsight

The Owl and The Surfboard

Technical card

Imaging telescopes or lenses: TS-Optics PHOTOLINE 115 mm F7 triplet apo

Imaging cameras: ZWO ASI 294MM Pro (cooled)

Mounts: Sky-Watcher EQ-6R Pro SynScan

Guiding telescopes or lenses: The Bellavia Basic-II 50mm f/7.5 guidescope

Guiding cameras: ZWO ASI 290MC

Focal reducers: Starizona Apex-L ED 0.65x Reducer

Software: Pleiades Astrophoto PixInsight  ·  IDEIKI AstroPhotography Tool (APT)  ·  Stark Labs Nebulosity 4.2  ·  Annie's Astro Actions V7  ·  Noel Carboni's Astro Tools for PhotoShop Noel Carboni Actions  ·  SharpCap Pro 3.2

Filters: L  ·  R  ·  B  ·  G

Dates:March 13, 2021

B: 20x180" (1h) (gain: 60.00) -10C bin 1x1
G: 20x180" (1h) (gain: 60.00) -10C bin 1x1
L: 60x60" (1h) (gain: 60.00) -10C bin 1x1
R: 20x180" (1h) (gain: 60.00) -10C bin 1x1

Integration: 4h

Darks: ~30

Flats: ~30

Flat darks: ~30

Avg. Moon age: 0.07 days

Avg. Moon phase: 0.00%

Bortle Dark-Sky Scale: 4.00

Mean SQM: 20.50

Mean FWHM: 3.60

Temperature: 3.00

Basic astrometry details

Astrometry.net job: 4312313

RA center: 11h 13' 5"

DEC center: +55° 20' 56"

Pixel scale: 0.914 arcsec/pixel

Orientation: 270.784 degrees

Field radius: 0.831 degrees

Resolution: 5448x3632

Data source: Traveller


The Owl Nebula, Messier 97, NGC 3587, is a planetary nebula located approximately 2,030 light years away in the constellation Ursa Major. It was discovered by French astronomer Pierre Méchain on February 16, 1781. When William Parsons, 3rd Earl of Rosse observed the nebula in 1848, his hand-drawn illustration resembled an owl's head. It has been known as the owl nebula ever since.

The nebula is approximately 8,000 years old. It is approximately circular in cross-section with a little visible internal structure. It was formed from the outflow of material from the stellar wind of the central star as it evolved along the asymptotic giant branch. The nebula is arranged in three concentric shells, with the outermost shell being about 20–30% larger than the inner shell. The owl-like appearance of the nebula is the result of an inner shell that is not circularly symmetric, but instead forms a barrel-like structure aligned at an angle of 45° to the line of sight.

The surfboard galaxy, Messier 108, NGC 3556, is a barred spiral galaxy in theconstellation Ursa Major. It was discovered by Pierre Méchain in 1781 or 1782. From the perspective of the Earth, this galaxy is seen almost edge-on.
This galaxy is an isolated member of the Ursa Major Cluster of galaxies in the Virgo supercluster. It has a morphological classification of type SBbc in the de Vaucouleurs system, which means it is a barred spiral galaxy with somewhat loosely wound arms. The maximum angular size of the galaxy in the optical band is 11′.1 × 4′.6, and it is inclined 75° to the line of sight.

This galaxy has an estimated mass of 125 billion times the mass of the Sun and includes about 290 globular clusters. Examination of the distribution of neutral hydrogen in this galaxy shows shells of expanding gas extending for several kiloparsecs, known as H1 supershells. These may be driven by bursts of star formation activity, resulting in supernovae explosions. Alternatively they may result from an infall of gas from outside the galaxy or by radio jets.


Sky plot

Sky plot


The Owl and The Surfboard, 


            Steven Bellavia