NGC 6604 is a young open cluster of stars in the equatorial constellation of Serpens, positioned about 1.5° north of the Eagle Nebula (M 16) low in our southern sky. It is located at a distance of 4,580 light years from the Sun. This cluster is embedded in an HII nebula which bears the designation Sharpless 54. The older stellar population in this region has an average age of 4-5 million years. They are grouped in the open cluster NGC 6604.
Astro photographers often overlook the cluster. They favor its more prominent neighbor, the Eagle Nebula (also known as Messier 16). The nebula lies a mere wingspan away. The framing of this picture shows a beautiful object, NGC 6604. It places the star cluster in a landscape of surrounding gas and dust clouds.
Sh2-54 belongs to an extended region of nebulae that includes the Eagle Nebula and the Omega Nebula.
The Elephant’s Trunk Nebula in the constellation Cepheus is a popular object for Astro photographers. It is ideal for imaging during late summer and early fall. The trunk itself is a dark, dense, and elongated globule cloud. It consists of interstellar gas and dust within the much larger ionized gas region IC 1396.
This globule is commonly called the Elephant’s Trunk nebula. The name comes from its appearance at visible light wavelengths. It is the dark, dense globule IC 1396A. This globule features a dark patch with a bright, sinuous rim. The bright rim is the surface of the dense cloud. A very bright, massive star (HD 206267) just to the east of IC 1396A illuminates and ionizes it.
The massive blue star is in the center of the image. This star ionizes the entire IC 1396 region. Dense globules can protect themselves from the star’s harsh ultraviolet rays.
I chose to photograph this with the Skywatcher Esprit 120 telescope. I used an ASI2600MC Pro Astro camera. Additionally, I used a Radian Ultra Quad-band Narrow band filter. My session management software is APT 4.56. Running on a mini-pc mounted on the telescope it controls everything, coordinating the activities of several pieces of technology. This photograph contains 248 subs for a total exposure of 13.88 hours. Two entire nights, Sept 8 & 9, 2024.
I’m presenting the image in two color palettes. The first is its natural color, with no color mapping applied. IC 1396 is a large cloud of faintly glowing gas, composed mainly of hydrogen which appears very red in long exposure photography. The second palette is known as the Hubble palette, HOO. In this the Ha and Oiii channels are blended to achieve a more pleasing optical presentation of the image. Very common approach.
A little over 4 years into this hobby I have finally imaged M 27. The RC8, at 1625mm of focal length, allows me to capture the details without cropping the image.
The Dumbbell Nebula is a planetary nebula. It is a nebulosity surrounding a white dwarf in the constellation Vulpecula, at a distance of about 1360 light-years. Messier 27 is bright and, at first, appears a little small. However, large expansions of gas are visible around the nebula in long exposure photos.
The first exposure I took was 120 seconds. It was far too bright and I could see that the core would be overexposed after stacking a lot of images. I’m only using a broadband light pollution filter so I went with 60 second exposures for this project. In all I used 344 exposures captured using APT 4.56.
Like many nearby planetary nebulae, the Dumbbell contains knots. Its central region is marked by a pattern of dark and bright cusped knots and their associated dark tails. The knots vary in appearance from symmetric objects with tails to rather irregular tail-less objects. Similarly to the Helix Nebula, the heads of the knots have bright cusps which are local photoionization fronts.
The stars in the image stand out for me. There are many yellow and red stars, along with a few blues that jump out. Such an interesting part of our sky.
The Omega Nebula is also known as Messier 17 (M17). It is one of several brilliant deep-sky astrophotography targets located in the constellation Sagittarius. It is also known as the Swan Nebula, Checkmark Nebula, Lobster Nebula, and the Horseshoe Nebula.
The Omega Nebula is one of the largest star-forming regions in our galaxy. It is located between 5,000 and 6,000 light-years from Earth. It contains more gas than the Orion Nebula. This makes it one of the best places to study how stars form.
The Omega Nebula is located just to the south of the Eagle Nebula (M 16). It is also north of the Trifid Nebula (M 20) and the Lagoon Nebula (M 8). These southern targets are visible during May – Aug.
The name is derived from the resemblance to the Greek letter, omega.
This image is 8 hours of exposure gathered in 2023 and 2024. All image acquisition was performed using APT. Processed manually with PixInsight.
I used the star cluster as the central focus for this image. 112 3 minute exposures with an 840mm Skywatcher Esprit 120ED refractor telescope paired with a ZWO ASI2600MC astro camera.
NGC6530 is a young, open cluster of stars. It is in the southern constellation of Sagittarius. It is located some 4,300 light years from the Sun. The cluster exists within the H II region known as the Lagoon Nebula, or Messier 8. More than two dozen stars are visible.
Like many nebulae, M8 appears reddish in time-exposure color photos. However, it looks gray to the eye peering through binoculars or a telescope. This is because human vision has poor color sensitivity at low light levels.
The nebula contains a number of Bok globules. These are dark, collapsing clouds of protostellar material. The most prominent globules have been catalogued. The platesolved and annotated version in this astrobin link shows everything within the frame. https://astrob.in/y6m8f5/0/
The Lagoon Nebula also contains at its centre a structure known as the Hourglass Nebula.
Messier 16 is also known as the Eagle Nebula or the Star Queen Nebula. It is considered an emission nebula in the constellation Serpens. It contains the Pillars of Creation. It’s located in the Milky Way’s Sagittarius Arm, about 7,000 light-years away from Earth. Parts of the Eagle Nebula are emission nebulas. The clouds of gas and dust are so hot they produce their own light. Other parts are dark nebulas. They are made of cold gas. These parts are only visible because of the silhouettes they create against the nebula’s glowing backdrop.
The Pillars of Creation are wispy columns of gas and dust in the nebula’s southern region that hide newborn stars. The Hubble Space Telescope’s 1995 image of the Pillars of Creation made them famous. The nebula’s dark silhouette near its center, which includes the Pillars of Creation, inspired the names “Eagle” and “Star Queen”.
The Eagle Nebula also contains the young star cluster NGC 6611. The nebula has several active star-forming regions. One of these is the Pillars of Creation. Here, gravity pulls gas clumps together to form stars. The wavy lines at the edges of some pillars are ejections from forming stars that collide with clouds of material. These collisions can also create bow shocks, which can form wavy patterns. The crimson glow comes from energetic hydrogen molecules that result from these jets and shocks.
This image was created from 117 240″ exposures captured using APT and calibrated/integrated using PixInsight. APT coordinates all of the technology used in imaging. This includes the cooled astro camera (ASI2600MC). It also includes the Telescope and its focusing (SW Esprit 120ED). Additionally, it includes the Eq6r Pro Mount that tracks with the stars.
A barred spiral galaxy located in the constellation Coma Berenices, about 40 million light-years away. It is an intermediate galaxy. It has a prominent ring structure. It is roughly the size of the Milky Way at over 100,000 light-years across. NGC 4725 is unique in that it only has one spiral arm, while most spiral galaxies have two or more. The galaxy’s center has a bar of stars. It is surrounded by a ring of stars. Astronomers call this formation a ringed barred spiral galaxy.
In this sharp color composite image, the solo spira mirabilis seems to wind from a prominent ring of bluish, newborn star clusters. It appears to originate from a distinct ring. The ring consists of bluish, newborn star clusters. It also appears to wind from red tinted star forming regions. The odd galaxy also sports obscuring dust lanes a yellowish central bar structure composed of an older population of stars. Also included in the frame is NGC 4712. It sports a noticeably more traditional spiral galaxy look. NGC 4712 is a more distant background galaxy.
Imaged 5/1, 5/10 and 5/11. The night of 5/10 was our Aurora Borealis event. Imaged from 21:30 to 02:00 each of these evenings. 136 4 minute subs were included, or 9 hours of exposure. Gear includes an f8 GSO RC8 telescope at 1625mm, an ASI071MC astro camera cooled to 15f, and an EQ6r Pro mount.
I continue my efforts in imaging reflection nebula from the vdB catalog. IC 4601, or vdB 103, is a bluish reflection nebula. It is located in the constellation Scorpius, about 420 light-years away from Earth.
It’s part of a larger area called the Blue Horsehead. Reflection nebulae are clouds of gas and dust. They shine by reflecting light from nearby stars. They do not create their own light. vdB 103’s blue color comes from the blue light reflected by the nebula’s gas and dust. This light is from two bright blue giant stars on the right. A double star on the left also contributes. The nebula’s brightness depends on the density and size of the reflecting grains. It also depends on the color and brightness of nearby stars.
Another of the globular cluster targets on my list, M12 is bright and colorful. This image consists of 137 60 second subs taken with a GSO RC8 and a ZWO ASI071MC Pro camera cooled to 15f, riding an EQ6r Pro munt. Certainly a challenging night for imaging as we experienced a very rare Aurora this night here in the hills of NC. Seeing and transparency were poor and the wind was present so guiding was not the best. Still, I’m happy with it!
Messier 12 (M12), also known as the Gumball Cluster, is a globular cluster of stars in the constellation Ophiuchus. It’s located about 15,700–23,000 light-years from Earth and has a diameter of 75 light-years. M12 is one of the brightest of the seven Messier globulars in Ophiuchus, and it’s approaching our solar system at a speed of 16 kilometers per second.
M12 has fewer low-mass stars than expected, and astronomers believe that gravity has stripped many of them from the cluster as it passed through denser areas of the Milky Way. It’s thought that M12 may have lost up to one million stars in this way.
Sh2-274, also known as the Medusa Nebula or Abell 21, is a planetary nebula in the constellation Gemini.
It is located 1,500 light-years away and has an estimated diameter of 4 light-years. The nebula is around 8,800 years old and was discovered in 1955 by UCLA astronomer George O. Abell
A planetary nebula is a region of cosmic gas and dust formed from the cast-off outer layers of a dying star. Despite their name, planetary nebulae have nothing to do with planets.
When stars with an intermediate mass (greater than 80% of the Sun’s mass, but less than eight times its mass) die, they expand to form red giants. The dying star will continue to expel gas, whilst simultaneously the remaining core of the star contracts and temporarily begins to radiate energy again. This energy causes the expelled gas to ionise, meaning that the atoms and molecules in the gas become charged and begin to emit light. The cast-off glowing gas is known as a planetary nebula. Therefore, planetary nebulae are classified as emission nebulae, and are entirely unrelated to planets.
The misnomer came about because of a historical misclassification. 250 years ago, astronomers thought they were looking at gas planets when they observed the colourful spectacle of planetary nebulae through their less powerful telescopes. Planetary nebulae only last for about 20 000 years, making them a very short-lived part of the stellar life cycle.
