Celestial hemisphere:  Northern  ·  Constellation: Cassiopeia (Cas)  ·  Contains:  1 Per  ·  10 Per  ·  11 Per  ·  11 bet Cas  ·  12 Cas  ·  12.70  ·  14 lam Cas  ·  15 kap Cas  ·  17 zet Cas  ·  18 alf Cas  ·  19 ksi Cas  ·  24 eta Cas  ·  25 nu. Cas  ·  26 ups01 Cas  ·  28 ups02 Cas  ·  32 Cas  ·  33 tet Cas  ·  35 Cas  ·  37 del Cas  ·  39 chi Cas  ·  4 g Per  ·  44 Cas  ·  45 eps Cas  ·  5 Per  ·  52 Cas  ·  53 Cas  ·  55 Cas  ·  626 Notburga  ·  7 chi Per  ·  8 Per  ·  And 811 more.
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Cassiopeia - a starry portrait, Tom Gray
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Cassiopeia - a starry portrait

Revision title: Reprocessed in Nebulosity 4 with correct colour matrix and crop

Getting plate-solving status, please wait...
Cassiopeia - a starry portrait, Tom Gray
Powered byPixInsight

Cassiopeia - a starry portrait

Revision title: Reprocessed in Nebulosity 4 with correct colour matrix and crop

Equipment

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Acquisition details

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Description

This is my second image with my AA 183C pro camera - the region immediately around the constellation of Cassiopeia - in mythology the somewhat haughty wife of King Cepheus of Ethiopia. 

Imaged through a 28mm Pentax SLR lens, at f2.8 (seen in the familiar iris pattern around the brighter stars), the image comprises just 25 minutes data at gain 20 using 60s exposures. Data were captured at full resolution in Nebulosity 3, pre-processed with 10 dark frames (but no flats), debayered, aligned and stacked in Nebulosity 4. This was too much for my ageing astronomy laptop, with file sizes at 135MB each (jpeg version in Revision C).

Taken on a blustery night, limiting me to imaging behind the house with just a narrow window of sky, this is a cropped image of the full frame (revision B) removing obvious artefacts - the corner of the house, an overhanging shrub and a small rain droplet on the lens. Binned 2x2, cropped and processed in Startools with a gentle wipe and stretch, followed by deconvolution, colour balancing and final noise reduction.

Given the conditions, rough polar alignment and basic tracking, I’m pleased with the resolution, colour and detail visible - as well as the iconic ‘W’ outlining the constellation, several recognisable objects are visible including the double cluster bordering Perseus (see annotations Revision D).

Comments

Revisions

  • Cassiopeia - a starry portrait, Tom Gray
    Original
  • Cassiopeia - a starry portrait, Tom Gray
    B
  • Cassiopeia - a starry portrait, Tom Gray
    C
  • Cassiopeia - a starry portrait, Tom Gray
    D
  • Final
    Cassiopeia - a starry portrait, Tom Gray
    E

B

Title: Full frame 2x2 binned

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C

Title: Full resolution stack

Description: This is the full stack- calibrated (darks only) and aligned in Nebulosity 4.

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D

Title: The plate solve from Astrometry.net

Uploaded: ...

E

Title: Reprocessed in Nebulosity 4 with correct colour matrix and crop

Description: Having established the correct matrix and offsets, I have re-processed this cropped image.

Uploaded: ...

Sky plot

Sky plot

Histogram

Cassiopeia - a starry portrait, Tom Gray