ASTRO:
     type=emission nebula
     mag=7.4
     const=Cassiopeia
     dist=9500 ly
     size=97 ly
IMAGE:
     location=Emerald Bay community, Lake Palestine, Texas, USA
     BrtlCls=4
     moon=6%
     exposure=CMOS OSC: 44x300s (3.7h), G100
     color palette=HOO
EQUIPMENT:
​     optics=ES102CF APO / Stellarvue 1.0x fltnr, FL=714mm, f/7.0
     camera=ZWO ASI2600MC-Pro
     filter=Optolong L-eXreme DNB
     mount=Celestron AVX EQ
     guiding=Orion 60x240mm, ZWO ASI224MC
SOFTWARE:
     acquisition=Stellarium, NINA, PHD2
     processing=PixInsight (RCAstro), Photoshop (APF-R, WebSharpPro), LrC

A Cosmic Feast: Sh2-184, famously known as the Pacman Nebula (and also catalogued as NGC 281 and IC 11), is a glowing H II region located roughly 9,500 light-years away in the constellation Cassiopeia.  It lives and feeds in the part of the Milky Way known as the Perseus Spiral Arm.   This striking cosmic character is a massive factory of stellar birth.  It feeds on the powerful emissions and stellar winds of an energetic open cluster of newborn stars known as IC 1590 measuring roughly 20×30 arcmin across, and associated with the multiple star system, B 1.   Collectively, all these sub-components form Sh2-184, spanning appx 97 ly across, and making it almost 3x larger than the Orion nebula.  But because it is so far away, it spans a visually apparent area of sky appx 40 arcmin across, or roughly ⅓ larger than Earth's full Moon.  ﻿
The Glow:  Intense ultraviolet radiation from hot, young stars ionizes the surrounding hydrogen and oxygen gases.  This process causes the nebula to emit its signature vibrant reddish and blueish hues.
The Silhouette:  Dark, dense lanes of interstellar dust and gas form the "mouth" of the Pacman shape.  These regions block background light and conceal active sites where future stars are currently forming.
Bok Globules:  The complex structure also features dark, condensing knots of dust called "Bok globules", which are small, dark clouds of cosmic gas and dust that, because of their high densities, block visible light.  They are named after their discoverer and research theorist, Dutch-American astronomer Dr. Bartholomeus "Bart" Bok.  Dr. Bok's globules typically span about one light-year across, weigh up to 50 solar masses, and act as isolated stellar nurseries where new stars can form.  These globules are actively undergoing gravitational collapse to forge entirely new star systems, possibly including brown-dwarf stars, which are thought to be precursors to new planetary systems, forming and containing orbiting planets like our home solar system.
Stellar Winds:  High-speed particle streams from the central stars continuously sculpt and erode the nebula cloud.  This dynamic process has already formed the classic "Christmas Ornament" open-bowl style common among many large nebulae regions; and as-is so very popular among amateur astrophotographers.  The stars of IC 1590 are expected to continue reshaping this cosmic arcade character for millions of years to come.  
﻿
While it looks like a 1970's video game character rushing across the northern sky to chomp on cosmic dots, this giant is actually consuming its own gas reserves to breed the next generation of stars.  It turns out the universe loves retro arcades just as much as we do, though this particular high score-maker takes a few million years to log.﻿
Due to its high apparent magnitude of 7.4, the nebula region is visible in amateur telescopes from dark sky locations.  The use of an OIII visual filter is recommended to help boost contrast and improve visibility.  But by far, the most popular way today's modern astronomers are capturing this colorful, giant beast is through the use of modern astro-photographic equipment, techniques and image processing.

260810 - Sh2-184 "Pacman" nebula