LBN 438, The Sandworm Nebula

Image Title: Shai-Hulud is back in Lacerta

Copyright: Pierre Drumel - Pascal Gouraud - Alentejo Remote Observatory

Date image was taken: September 24, 2025

Location: Alentejo Remote Observatory (Portugal)

Data Acquisition Method: Personal Telescope Setup

Description and Details: LBN 438 is a faint obscur nebula located in the Lacerta constellation which is also known as the sandworm (named Shai-Hulud from the Dune science fiction series)
It is illuminated by interstellar radiation known as Extended Red Emission (ERE). ERE is a relatively recent discovery (1975) and is a photo-luminescence process whereby hydrogenated amorphous carbon is illuminated by interstellar photons in the 500 to 1000nm spectral range. Although the nebula also contains ionized hydrogen, it only emits a relatively weak Ha signal.
Considering the difficulty, we decided to use broadband filters to acquire the target completed by Ha Filter for the weak Ha part.
At the top of the nebula is a reddish glow, a faint red prominence pointing towards a small binary system. The nebula is surrounded by very bright blue stars (not visible here as outside the field of view) which likely contribute to the ionization of the hydrogen clouds.
If you look closely at the background you will also be able to see various small background galaxies

Technical Details
The image was captured using a cooled ASI2600MM mono camera equipped with (LRGBSHO) filters and a 304mm Ritchey-Chretien telescope with a 2m focal length, on an Astrophysics AP900 mount. (Location : Alentejo Remote Observatory)
The cumulative exposure time is 94 hours, including 35 hours in Luminance mode, 29 hours of Ha and 29 hours in RGB mode.
The Processing was quite a bug challenge to manage the faint areas and subtle details in the head of the sandworm and inside the tail/ We choose the LhaRHAGB blending mode and We made several attempts before getting at this result.
Hope you will enjoy !!!

Name: Pascal GOURAUD