ASTRO:
     type=emission / reflection nebula
     const=Vulpecula
     mag=7.1
     dist=6000 ly
     size=70 ly
IMAGE:
     location=Emerald Bay community, Texas
     BrtlCls=4
     moon=53% WnGb
     exposure=CMOS OSC: 49x300s (4.1h), G100
     palette=HOO
EQUIPMENT:
​     optics=ES102CF APO / Stellarvue 0.8x rdcr, FL(eff.)=571mm, f(eff.)/5.6
     camera=ZWO ASI2600MC-Pro
     filter=Optolong L eXtreme Dual NB, Ha + OIII, 7nm band width
     mount=Celestron AVX
     guiding=Orion 60x240mm, ZWO ASi224MC
SOFTWARE:
     acquisition=Stellarium, NINA, PHD2
     processing=PixInsight (RCAstro), Photoshop (Lumenzia, WebSharp-Pro), LrC

Like many deep sky star clusters that include associated nebulae, open star cluster NGC 6823 only recently acquired the common name, "Pillars of Vulpecula".  The associated nebula is slowly turning gas clouds into stars.  The star cluster spans about 50 light years and lies about 6000 light years away toward the constellation of Vulpecula, the Fox.  Together with its associated reflection nebula (depicted by its faint bluish hue), the cluster is embedded in a large, faint emission nebula called Sh2-86 (depicted in red).  The center of the star cluster formed only about two million years ago (very recent by astronomical standards) and is dominated in brightness by a host of bright, young and hot, blue stars.  Outer extents of the cluster, visible in the featured image outside of the central cluster, contain even younger stars forming the core of the Vulpecula OB1 stellar association.  The stars and pillars of Sh2-86, in turn, are part of the even larger and more faint emission nebula, NGC 6820.   Beautiful and huge pillars of gas and dust get their elongated shape by erosion from hot radiation and stellar winds generated from the brightest stars in the cluster.  Striking dark globules of gas and dust are also visible across the upper left of the central region of the nebula.

The size of Sh2-86 is actually larger than the very popular M42, Orion Nebula; but because it is so much further away, its apparent size is much smaller.   ...M27, the Dumbbell Nebula, is found 3° (arc-degrees) to the east, and star α (alpha) Vulpeculae, the brightest star in the host constellation, is appx 3° to the west.  This nebula features the "open-bowl Christmas ornament" configuration that is so popular and sought-after by amateur photographers.  The most popular nebula exhibiting this type of configuration is M16, the Eagle Nebula which of course encases the very well known, "Pillars of Creation" within its open-bowl.  But because Sh2-86 is oriented "edge-on" to our line of sight, the open side of the bowl is believed to not be readily visible; we only see the beautiful "glow" of the nebula's stellar reflections and emissions from deep within its bulging space-clouds.

IMAGER'S COMMENTS:This image was derived from stacking sub-exposures captured while using a dual narrow-band filter paired together with a cooled, dedicated One-Shot-Color ("OSC") astronomical camera.  During processing, the "HOO" (Hydrogen-Oxygen-Oxygen) palette of colors was used, being an assignment of each element's visibility to the traditional Red, Green, and Blue photographic color channels, respectively.  Amateur Astrophotographers often use a color assignment like this to enhance visual contrast, and to add artistic 'drama' to their photographs.  While being one of the most popular combinations, the HOO palette is only one among many color palettes used by today's astro-imagers.

250618 - Sh2-86 "Pillars of Vulpecula"