Pacman Nebula: Definition, Facts

The Pacman Nebula, catalogued as NGC 281, is an H II star-forming region discovered in 1881 by Edward Emerson Barnard. 
Its optical images reveal a dark mouth that gives the 35 arcminute cloud its nickname. The object was recently recorded from Mayhill, NM, USA, through a 24-inch f/6.5 reflector equipped with an Astrodon MonsterMOAG off-axis guider and a FLI PL16803 4096×4096pix detector, then processed in CCDStack to build a 21-hour total exposure: 12 h Hα, 8 h OIII, 1 h RGB.

What is the Pacman Nebula?

The Pacman Nebula, cataloged as NGC 281, is an emission nebula in the constellation Cassiopeia. The Pacman Nebula resembles Pacman, and its optical image shows a dark mouth. Its infrared image shows bright dust, and it contains several Bok globules.

The Pacman Nebula is a large emission nebula, an HII region, and a star-forming region catalogued as NGC 281 and known as Sharpless 184, Sh2-184, IC 11, and LBN 616. It appears near the orange giant Schedar in the constellation Cassiopeia and is part of the Perseus Spiral Arm. Edward Emerson Barnard discovered and described it as “a large faint nebula, very diffuse.”

Optical images show dark dust lanes cutting into bright clouds of gas, forming the mouth shape that gives the nebula its video-game nickname. Within the nebula lies the open star cluster IC 1590, which contains young stars and the multiple star B1. Infrared Spitzer images reveal that the dust in this region glows brightly, while the mouth of the Pacman character appears dark because of obscuration by dust and gas.

What is the process of star formation in the Pacman Nebula?

Star formation in the Pacman Nebula begins where Bok globules, small isolated dark nebulae containing dense amounts of dust and gas, drift within the galactic area. Ultraviolet light from high mass stars in NGC 281 erodes these reservoirs, compressing gas and dust into collapsing cores that become newly forming stars.

Once born, the cluster’s young massive stars are powering the pervasive nebular glow with intense radiation and strong winds flowing outward. These winds continue to sculpt the remaining dust and gas, triggering further star formation in the Pacman while also carving the characteristic shapes seen in composite images of NGC 281.

Infrared observations from Spitzer reveal emerging protostars embedded deep within the clouds, whereas X-ray data from Chandra trace the hottest, most massive members already dominating the region. Eventually, the same high mass stars will end their brief lives as supernovas, enriching the galactic area through robust winds and the eventual deaths of massive stars, thereby seeding future generations of star formation in the Pacman Nebula.

When was Pacman Nebula discovered?

The Pacman Nebula was discovered on 16 November, 1881, by Edward Emerson Barnard.

What are the facts about the Pacman Nebula?

The facts about the Pacman Nebula are presented below.

• The Pacman Nebula contains a small open star cluster IC 1590.
• The Pacman Nebula contains dark dust lanes.
• The Pacman Nebula contains several Bok globules.
• The Pacman Nebula is located in Cassiopeia.
• The Pacman Nebula is about 9,200 light years away.
• The Pacman Nebula stretches 48 light years across.
• The Pacman Nebula has PIA Number PIA14731.
• Pacman Nebula occupies 35 arcminutes of the apparent sky.
• The Pacman Nebula’s dark lane is interspersed with glowing hydrogen clouds.
• The Pacman Nebula is easy to find because it lies near Cassiopeia’s W.
• Pacman Nebula appears near orange giant Schedar.
• HD 5005 is brightest star of Pacman Nebula.
• In optical images the mouth of Pacman Nebula appears dark because of dust and gas.
• In the infrared Spitzer image the dust in Pacman Nebula glows brightly.
• NGC 281 known as Sh2-184, LBN 616, IC 11, and LBN 123.17‑06.28.
• NGC 281 was discovered by Edward Emerson Barnard in August 1883.
• NGC 281 is located about 6,500 light years from Earth.
• NGC 281 stretches 48 light years (35 arc minutes) across.
• NGC 281 has right ascension 00 h 52 m 59.35 s.
• NGC 281 is about 1,000 light years above the plane of the galaxy.
• NGC 281 contains young stars.
• NGC 281 has been studied and observed by astronomers for over 100 years.
• Within the Pacman Nebula is the young open star cluster IC 1590, with an estimated age of 3.5 million years

Can you see the Pacman Nebula through a telescope?

Yes, you can see the Pacman Nebula through a telescope. The Pacman Nebula is glimpsed through an 8 × 50 finder, but this only reveals a faint smudge. Relatively dim and diffuse nebulae like the Pacman Nebula are completely invisible in your field of view unless you employ larger optics and filters. An 8-inch telescope with an O-III filter is required to see the unique shape that gives the nebula its nickname. Observers under light-polluted skies must add a broadband light-pollution filter to help separate the nebula from the city sky.