SUNSET: 
0
Photographer:
Hal Heaton
Location of Photo:
Chilescope Telescope 3
Date/Time of photo:
June 28-30, 2024
Equipment:
A guided ASA Newtonian reflector (0.5 meter aperture, f/3.8); an FLI Proline 16803 CCD camera (unbinned); Astrodon broadband (300 sec exposures - red, green, blue) and narrowband (600 sec exposures - H_alpha and OIII ) filters.
Description:
NGC 6164 is a complex bipolar nebula in Norma near the Dragons of Ara that surrounds the massive binary O-star system HD 148937 at the center of this image. It is enriched in carbon, nitrogen, and oxygen, with the highest densities of those elements found in regions of the nebula most distant from the binary. Models indicate that HD 148937 was originally a triple star, likely containing a close inner-binary orbited by an outer member. This inner binary underwent a merger a few thousand years ago, which produced a magnetic field in the merged star and inner nebula. The extended and more distant bluish nebulosity surrounding the inner nebula likely resulted from an explosive mass-loss event before the stellar merger occurred. The image is presented with east down and north to the left.
