Observation by Peter Goodhew FRAS: Sh2-176

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Peter Goodhew FRAS


Peter Goodhew FRAS


2022 Aug 09 - 15:50


2022 Aug 09 - 15:53


Sharpless 176

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Field centre

RA: 00h31m
Dec: +57°22'
Position angle: +0°40'

Field size

0°32' × 0°23'

  • APM TMB LZOS 152 Refractors
  • QSI6120 CCD Cameras
  • 10Micron GM2000 HPS mount

32 hours 15 minutes total integration (HaRGB)


Fregenal de la Sierra, Spain

Target name




About this image

Sh2-176 is a faint planetary nebula in Cassiopeia. It has a surface brightness of 15.5 mag/arc-sec2 and a hydrogen-rich central star. It was discovered to be a planetary nebula by Sabbadin et al in 1977. It is approximately 490 light-years away with estimates for its age ranging from 24,000 to over 180,000 years old based on the computed kinematics (expansion rate and nebular diameter). Expanding at 19 km/sec, Sh2-176 has been estimated to span 3.1 to over 22.8 light-years across depending on the source. Its asymmetricity is believed to be the result of bow shocks involving the interstellar medium and the planetary nebula itself where, the brighter portion of the nebula represents the interaction of the nebula meeting up against the interstellar medium as it moves through space.  The central star associated with Sh2-176 is a blue subdwarf with a magnitude of 18.74.
Data captured on my dual rig of 6" refractors at Fregenal de la Sierra in Southern Spain.
Data captured between 4-9 August 2022.
More information at https://www.imagingdeepspace.com/sh2-176.html

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