Shot on 25 Jan 20225 photosM 42
Orion Nebula
- Right ascension
- 5ʰ 35ᵐ 19ˢ
- Declination
- −5° 22′
- Constellation
- Orion
- Tonight
- Never sets
- no
- total exposure
- 6 h 10 min
- frames in the FITS archive
- 37
- imaging nights
- 4
- imaging period: 12–15 Mar
- 2021
Visibility and signal
Exposure by filter
- Hα2 h 10 min · 13 frames
- OIII2 h · 12 frames
- SII2 h · 12 frames
Share of each filter in the total exposure
- Narrowband filters
- 100%can be shot under the Moon
- Typical frame
- 600 s37 frames in total
- In one night
- 1 h 33 minaveraged over 4 nights
Altitude above the horizon tonight
Observing log4 nights · 37 frames
Photos of the objectEach photo is a separate processing; parameters and equipment are on the photo page
About the object
The Orion Nebula* (also known as Messier 42, M42, or NGC 1976) is a diffuse nebula located in the Milky Way. It is located south of Orion's Belt in the famous constellation Orion and is visible as the middle "star" in Orion's "sword". It is one of the brightest astronomical nebulae, with an apparent magnitude of 4.0, and can be seen with the naked eye even in light pollution.
Key Features
- Distance from Earth: about 1,344 ± 20 light-years.
- Size: The nebula extends for 25 light-years.
- Mass: approximately 2,000 solar masses.
- Location: Located in the same spiral arm of the Galaxy as the Sun.
The Orion Nebula is the closest star-forming region to us, making it a key object for studying the processes of star formation and planetary systems. Within it, astronomers have observed protoplanetary disks, brown dwarfs, turbulent gas motions, and photoionization of massive stars.
Trapezium Star Cluster
Within the nebula lies a young open star cluster known as the Trapezium:
- Diameter: about 1.5 light-years.
- Primary components: four bright stars that form an asterism. Under good observing conditions, two more stars can be distinguished, giving a total of six stars. - The entire region contains about 2,800 stars in a diameter of 20 light years.
The nebula is surrounded by the Orion Molecular Cloud Complex, which extends for hundreds of light years and encompasses the entire constellation of Orion.
Colors and Glow Features
- Green tint: associated with a low-probability electron transition in doubly ionized oxygen (the so-called "forbidden transition"), which occurs in the nearly molecular-free environment of deep space.
- Red color: emission from the Hα recombination line with a wavelength of 656.3 nm.
- Blue and violet: reflected light from massive O-type stars located at the center of the nebula.
The green glow was previously associated with a hypothetical element called nebulium, but this phenomenon was later explained based on atomic physics.
Interesting Facts
- The Orion Nebula is the most studied and photographed object in the night sky.
- It is visible to the naked eye as a fuzzy star in Orion's "sword".
- Runaway Stars: About two million years ago, the cluster may have been home to the stars AE Aurigae, 53 Arieti, and Mu Columbi, which are now moving away at over 100 km/s.