Messier 8, Messier 20, and Supernova Remnant G007.5−01.7

Image Title: Messier 8, Messier 20 and SNR G007.5-01.7

Copyright: Michael Sleeman

Date image was taken: June 12, 2025

Location: Namibia, Windhoek

Data Acquisition Method: Remote Observatory (Commercial)

Description and Details: This project combines SHO narrowband with RGB stars to reveal the complex interplay of ionized gas, molecular clouds, and shock structures in one of the richest regions of the Milky Way. The field includes three major objects with distinctly different astrophysical origins.


Messier 8: The Lagoon Nebula (H II region)

M8 is a massive star-forming complex located ~4,100 light-years away in Sagittarius. The nebula is strongly shaped by UV radiation and stellar winds from young O-type stars in the embedded NGC 6530 cluster. The characteristic “hourglass” region is a zone of active photoionization, where supersonic outflows from protostars carve cavities into dense gas.

Messier 20: The Trifid Nebula (Multi-type nebula)

M20 combines:

H II emission (red in RGB, mapped to SII/Hα in SHO),
reflection nebulosity (blue),
dark dust lanes dividing the core into its iconic “three-lobed” appearance.

SNR G007.5–01.7: Faint Supernova Remnant

A remarkably subtle structure in the SHO data is the supernova remnant G007.5–01.7, an expanding shell of ionized gas from a stellar explosion several thousand years ago.

The SNR is extremely low surface-brightness and only becomes visible through:

long integrations in OIII and Hα,
careful noise reduction,
enhanced contrast stretching of the outer shock boundary.

Exposure Times:
Ha / SII / OIII: ~22h each (300s per exposure)
R / G / B: 3h total (60s per exposure)

Name: Michael Sleeman

Website or Facebook Profile: https://astro.sleeman.at