The Ghost Nebula
The Ghost Nebula (Sh2-136) is a reflection nebula located in the constellation Cepheus. This object lies very close to the star cluster known as NGC 7023, and the Iris Nebula.
The Ghost Nebula spans roughly 2 light-years across and appears as a yellowish-brown color in photographs. Its appearance is indeed ‘ghostly’ which is the origin of its common name in the astronomy community.
The Ghost Nebula in Cepheus (Sharpless 136). 3.5 Hours Total Exposure.
The Ghost Nebula (Sh2-136) is not to be confused with the “Ghost of Cassiopeia” (IC 63), a different nebula in the nearby constellation of Cassiopeia.
The Ghost Nebula
- Type: Reflection Nebula
- Cataloged: Sh2-136, VdB 141
- Constellation: Cepheus
- Distance: 1,200 light-years
This interstellar field of stars and dust is 1,200 light years away and filled with faint, starlight-reflecting clouds.
The area of the night sky that this nebula resides in is known as the Cepheus Flare molecular cloud complex. Early stages of star formation occur within this reflection nebula.
It is a busy area of the night sky in terms of dark nebulae and interstellar dust. The following image showcases the area surrounding the Iris Nebula in detail.
The Iris Nebula and Ghost Nebula are within the same field of view at focal lengths of 400mm and below.
Detailed images of this nebula reveal the clouds of dust and reflected starlight in great detail.
Location in the Sky
In the northern hemisphere, the Ghost Nebula can be observed almost any time of year. From mid-northern latitudes, the constellation Cepheus is circumpolar.
The best time to observe and photograph the Ghost Nebula is between the months of August to November when Cepheus rises high overhead.
VdB 141 and NGC 7023 (The Iris Nebula) are found within a few degrees of each other in the night sky. Use the star map below for a better idea of their location.
Location of the Ghost Nebula and Iris Nebula in Cepheus. Sky and Telescope/IAU.
Sh2-136 Astrophotography
Sh2-136 is a challenging astrophotography target. It is a broadband subject that does not benefit from the use of narrowband filters.
To capture the true, natural colors of this nebula it is best to capture images from a dark sky location that is well away from city light pollution.
Another challenge of this project is the small relative size of the nebula. A telescope with a focal length of 1000mm or more is recommended.
The following image was captured using a monochrome dedicated astronomy camera and LRGB filters. The total exposure time is 4 hours.
The Ghost Nebula. Sky-Watcher Esprit 150. ZWO ASI2600MM Pro (LRGB).
To create an image with a stronger signal-to-noise ratio, image stacking software was used to calibrate and integrate the image data.
The calibrated master file was then processed in Adobe Photoshop and PixInsight to reveal the faint structures of the reflection nebula.
To practice your processing skills, you can try my image processing tutorial in Adobe Photoshop on the Iris Nebula and Ghost Nebula area with the real image data I collected.
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The Ghost Nebula by Adam Block/Mount Lemmon SkyCenter/University of Arizona.