SUNSET: 
0
Photographer:
Hal Heaton
Location of Photo:
Chilescope-Telescope 2
Date/Time of photo:
24 November and 3 December, 2019 (moonless)
Equipment:
Telescope: ASA 0.5-m field-corrected Newtonian (f/3.8); Camera: Unbinned FLI ProLine 16803; Filters: Astrodon H-alpha, OIII, SII; Exposure Time: 10-min/frame (stacked for 1-hr)
Description:
Situated in the northern outskirts of the Large Magellanic Cloud in Dorado, the expanding nebulae NGC 2020 (left) and NGC 2014 (right) offer spectacular views of the effects of massive star evolution on the surrounding interstellar medium. Shown in false-color to capture spatial patterns in their chemical composition, the brownish color of the large tenuous bubbles in NGC 2014 arises from the combined presence of primordial hydrogen (H-alpha, rendered as green in the Hubble Color Palette) and sulfur (SII-red) created by nucleosynthesis in star’s core that has been mixed upward into its outer layers. Each bubble was blown by the energetic wind from a single embedded star. The bluish-shaded haze enveloping portions of that nebula results from the ionization of oxygen by intense ultraviolet light emitted by those stars. In contrast, the flared ring-shaped nebula NGC 2020 to the left was produced by the explusion of the outer layers (i.e., the blue wall) of a single Wolf-Rayet star (HD 269748), which can be seen in projection at the ring’s center. As these layers are driven into more distant gas that was lost from the star during an earlier phase of its evolution, wisps of light emitted from ionized sulfur (red) are mixed into the still-prominent but fading bluish-light from ionized oxygen atoms. A short-exposure RGB image was blended subsequently into the scene to remove artificial coloration from the background star field. The image was processed initially in CCDStack v2, and post-processed using Photoshop CC2018 and GIMP; it is oriented with north upward, and east to the left.
