The Horsehead Nebula, the Flame Nebula, and IC 434
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Winter may not be everyone’s favorite season, but it is undoubtedly a time when we can admire some of the most beautiful constellations. One of them is the constellation Orion (Orion). Within this constellation, we can find numerous breathtaking deep-sky objects.
The constellation of Orion was named and placed in the sky by the ancient Greeks. In their mythology, Orion was the son of the sea god Poseidon and Euryale, one of the Gorgons—making him the nephew of the infamous Medusa with her snake-like hair. Orion was renowned as the greatest hunter to ever walk the Earth, capable of moving silently and even walking on water. He fell in love with the Pleiades, whom he still chases across the sky to this day. He died from the sting of a scorpion sent by the goddess Artemis. Since then, the constellations of Orion and Scorpius have been located on opposite sides of the celestial sphere. Even Orion’s faithful hunting dogs—Sirius and Procyon—were placed in the sky as the brightest stars of the constellations Canis Major and Canis Minor, respectively.
Interestingly, in the case of this constellation, Alpha Orionis (α Ori) is not the brightest star—the brightest is actually Beta Orionis (β Ori), also known as Rigel. Alpha Orionis, or Betelgeuse, ranks second in brightness. Located about 600 light-years from us, Betelgeuse is classified as a red supergiant. If placed in the position of our Sun, its surface would extend roughly to the orbit of Jupiter. Its reddish hue stands out among other stars, and the star is believed to be nearing the end of its evolutionary cycle, eventually exploding as a supernova. Near Betelgeuse, at the position representing Orion’s other shoulder, lies Gamma Orionis (γ Ori), known as Bellatrix. Lambda Orionis (λ Ori) is a fascinating multiple star system with several gravitationally bound components. South of Betelgeuse and Bellatrix lie three bright stars that form Orion’s Belt: Delta (δ), Epsilon (ε), and Zeta Orionis (ζ Ori), known as Mintaka, Alnilam, and Alnitak, respectively. Between Orion’s Belt and Rigel and Saiph (κ Ori) lies Orion’s Sword, which contains the Orion Nebula, visible even through binoculars.
In addition to the Orion Nebula, other fascinating deep-sky objects lie within the boundaries of this constellation. In Photo 1, I have marked the rectangular region where the nebulae discussed later in this article can be found.
Observations
January 31, 2019, around 10:30 PM – Zaborze (Poland)
Suburban conditions, moderate light pollution
The cool night and clear sky encouraged me to set up my equipment for observation. I managed to capture several dozen minutes of exposure, which, after appropriate processing, resulted in the photograph below.
The photograph shows the region of Orion’s Belt, featuring two of its main stars: Alnilam and Alnitak. Both are blue supergiants located about 1,300 light-years from Earth, with Alnitak being slightly closer. Alnitak is a triple star system consisting of ζ Ori B (the more distant component) and two closely spaced components: ζ Ori Aa (the primary Alnitak) and ζ Ori Ab. Also visible is Sigma Orionis (σ Ori), a quintuple star system approximately 1,150 light-years away. Near Alnitak lie at least four very intriguing and visually stunning nebulae.
The first is NGC 2024, also known as the Flame Nebula. This is an emission nebula and an H II region located about 1,500 light-years from Earth. It was discovered by William Herschel on January 1, 1786. The nebula resembles a flame with an angular diameter of about 0.5° and can be observed near Alnitak. In visible light, the Flame Nebula appears reddish due to the recombination of hydrogen atoms. Its ultraviolet radiation, responsible for ionizing the gas, likely originates from a young star within a cluster of hot stars visible in infrared wavelengths. This cluster is obscured by a dark band of dust that absorbs visible light, creating the nebula’s distinctive silhouette.
IC 434 is similar to the Flame Nebula in many ways, also glowing red due to its hydrogen content. However, it appears more diffuse and dimmer. Interestingly, it was also discovered by Herschel, precisely one month after his observation of the Flame Nebula.
Barnard 33, commonly known as the Horsehead Nebula, is a dark nebula with a strikingly distinctive silhouette. It was discovered in 1888 by Williamina Fleming using photographic plates. This nebula consists of cold gas and dust that absorbs visible light, appearing as a dark silhouette against the glowing backdrop of IC 434.
NGC 2023, on the other hand, is a reflection nebula located approximately 1,500 light-years from Earth. It surrounds the young, massive star HD 37903 (spectral type B). The star’s energy illuminates the surrounding gas and dust, giving the nebula its bright surface and making it a relatively easy object to study. Star formation processes are still ongoing within the nebula.
December 24, 2024, around 9:30 PM – Jaworzno (Poland)
Suburban conditions, moderate light pollution
Orion is such a magnificent constellation that I often admire it with the naked eye, without any photographic equipment. However, after some time since my previous imaging attempts, I once again pointed my telescope toward the region of Orion’s Belt, specifically near Alnitak.
Space is an immense realm filled with fascinating phenomena and mysteries that continually spark our curiosity. A glance at the night sky reveals hundreds of thousands of stars—each a distant sphere of gas whose light has traveled for billions of years to reach our planet. Our galaxy, the Milky Way, is just one of millions of such structures that make up the Universe. Galaxies, stars, planets, and black holes—all are parts of a larger cosmic picture that scientists strive to understand. Although space may seem beyond our reach, modern technology and human ingenuity allow us to explore what lies millions of light-years away. These discoveries not only expand our knowledge of the Universe but also offer insights into ourselves and our place in this infinite cosmos.
I must admit that the opportunity to observe and reflect upon such beautiful objects provides a deeply profound experience—both aesthetically and on a deeper, almost transcendental level.
Photo 1 Parameters:
- Total exposure time: 10 seconds (single shot)
- Panasonic dmc-fz7
- ISO: 400
- Lens: f=6mm
- Aperture: f/1.4
- Mount: photographic tripod
Photo 2 Parameters:
- Total exposure time: 40 minutes (stack of 20 RAW frames at 120s each, using an appropriate number of dark, bias, and flat frames)
- Canon EOS 300D
- ISO: 3200
- Lens: zoom type (used at fmax = 250mm)
- A filter was used to reduce the effects of artificial light pollution and atmospheric glow
- Mount: equatorial mount with tracking, aligned using the drift method and controlled by a custom-built system.
Photo 3 Parameters:
- Total exposure time: 50 minutes (stack of 200 RAW frames at 15s each)
- DWARF3
- Lens: f=150mm (aperture: 35mm)
- Mount: photographic tripod
Marek Ples