The Orion Nebula (also known as Messier 42, M42, or NGC 1976) is a diffuse nebula situated in the Milky Way south of Orion’s Belt in the constellation of Orion. It is one of the brightest nebulae, and is visible to the naked eye in the night sky. M42 is located at a distance of 1,344 light years and is the closest region of massive star formation to Earth. The M42 nebula is estimated to be 24 light years across. It has a mass of about 2,000 times that of the Sun.
De Mairan’s Nebula (M43) is a star-forming nebula with a prominent H II region in the equatorial constellation of Orion. It was discovered by the French scientist Jean-Jacques Dortous de Mairan some time before 1731, then catalogued by French astronomer Charles Messier on March 4, 1769. The De Mairan’s Nebula is part of the Orion Nebula (M42), being separated from the main nebula by a dense lane of dust known as the northeast dark lane. It is part of the much larger Orion Molecular Cloud Complex.
The main ionizing star in this nebula is HD 37061, which is positioned near the center of the H II region and located 1,300ly from the Sun. This is a triple star system with the brighter component being a single-lined spectroscopic binary. The main component is a blue-white hued B-type main-sequence star with a stellar classification of B0.5V or B1V. It has 19 times the mass of the Sun and 5.7 times the Sun’s radius. The star is radiating over 26,000 times the Sun’s luminosity from its photosphere at an effective temperature of 31,000 K. It is spinning rapidly with a projected rotational velocity of around 200 km/s.
The H II region of M43 is a roundish volume of ionized hydrogen centered on HD 37061. There is a dark lane crossing in front of the region from north to south, known as the M43 dark lane.
Sh2-279 (Running Man Nebula) is an HII region and bright nebulae that includes a reflection nebula located in the constellation Orion. It is the northernmost part of the asterism known as Orion’s Sword, lying 0.6° north of the Orion Nebula. The reflection nebula embedded in Sh2-279 is popularly known as the Running Man Nebula. The Running Man Nebula is a popular target for amateur astrophotographers, as it lies close to the Orion Nebula and has many nearby guide stars. The outline of the running man shows up primarily in photographs; it is difficult to perceive visually through telescopes, though the reflection nebula itself is visible in small to medium apertures in dark skies.
The Orion Nebula is one of the most scrutinized and photographed objects in the night sky, and is among the most intensely studied celestial features. While that may be true, it was a very difficult target to photograph without blowing out the core and the large stars. It is surrounded by hydrogen gas as seen in the red hues thoughout. The dark nebula of M43 as well as the Running Man nebula add character to the image.
The nebula has revealed much about the process of how stars and planetary systems are formed from collapsing clouds of gas and dust. Astronomers have directly observed protoplanetary disks, brown dwarfs, intense and turbulent motions of the gas, and the photo-ionizing effects of massive nearby stars in the nebula.
The Nebula is visible with the naked eye even from areas affected by some light pollution. It is seen as the middle “star” in the “sword” of Orion, which are the three stars located south of Orion’s Belt. The star appears fuzzy to sharp-eyed observers, and the nebulosity is obvious through binoculars or a small telescope.
The Orion Nebula contains a very young open cluster, known as the Trapezium due to the asterism of its primary four stars. Two of these can be resolved into their component binary systems on nights with good seeing, giving a total of six stars. The stars of the Trapezium, along with many other stars, are still in their early years. The Trapezium is a component of the much larger Orion Nebula Cluster, an association of about 2,800 stars within a diameter of 20 light years. Two million years ago this cluster may have been the home of the runaway stars AE Aurigae, 53 Arietis, and Mu Columbae, which are currently moving away from the nebula at speeds greater than 100 km/s (62 mi/s).
There has been speculation that the Mayans of Central America may have described the nebula within their “Three Hearthstones” creation myth; if so, the three would correspond to two stars at the base of Orion, Rigel and Saiph, and another, Alnitak at the tip of the “belt” of the imagined hunter, the vertices of a nearly perfect equilateral triangle with Orion’s Sword (including the Orion Nebula) in the middle of the triangle seen as the smudge of smoke from copal incense in a modern myth, or, in an ancient one, the literal or figurative embers of a fiery creation.
I encourage you to have a read of the wikipedia information available. The observing and photographic history of this complex is very interesting. Who knew that in the 1600’s people made telescopes?
Subscribe below for new post updates.
