M78 – Reflection Nebula

M78, in the Orion Complex, is a bright diffuse reflection nebula – a cloud of interstellar dust that shines with the reflected light of young stars. As with other objects in the Orion Complex, M78 is about 1,600 light years away. The smaller nebula toward the left is classified as NGC2071.


Exposure  • Full image: 11⅓ hours (68 @ 600 seconds) @ -20°C
 • Core stars: 7½ minutes @ -20°C
   ☞ 10 @ 10 seconds
   ☞ 10 @ 15 seconds
   ☞ 10 @ 20 seconds
 • Dusk flats
 • Camera position angle: 284°
Processing  • With PixInsight:
   ☞ Calibrate, star-align, and integrate subframes
   ☞ Reduce background noise
   ☞ Process for high-dynamic range
 • Noise reduction with Topaz DeNoise AI
 • Final tweaking in Photoshop CS6
Date and Location  • November 4, & December 24, 2019
 • Louisa County, Virginia, USA
Equipment
  • TMB-130SS APO refractor @ f/7 on an A-P 1200 mount
 • ZWO ASI-1600MC Pro color camera
 • Guided with an ST-402 camera on a 60mm f/5 scope
 • Imaging and autoguiding with MaxIm DL 6.20
 • Automated image acquisition with ACP Observatory Control

Processing M78

The new stars eroding the dust are very bright. If the image is processed to show the dimmer nebulosity, the core region becomes so bright the stars can't be seen.

PixInsight offers tools to deal with such a "high dynamic range" (HDR) image. HDR tools blend short exposures that show only the stars and bright region with longer exposures that have the nebulosity plus the too-bright core. This blending preserves the nebulosity, but dims the core enough to make the stars visible.

To prepare, I acquired multiple short exposures of the stars. I processed these subs normally, then used Pixinsight's HDR tools to combine them with the full-image subs acquired 1¾ months earlier to produce this final image.


The Orion Region

This region of the winter sky contains several beautiful deep-space objects in addition to the M78 Nebula pictured above.

Hover your mouse over a yellow arrow below to see the name of an object. Click on the arrow to see my image of it.


Updated May 23, 2023