220526 - "Rho Ophiuchi" cloud complex
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ASTRO:
type=interstellar cloud complex const=Scorpio / Ophiuchus dist=360 ly size=1 ly mag=4.6 IMAGE: location=EB Driveway BrtlCls=4 moon=19% WnCr exposure=DSLR OSC: 571x45s (7.1h), ISO1600, f/4.8 EQUIPMENT: camera=Nikon D90 (mod) optics=NIKKOR 70-300mm zoom @ 135mm filter=(none) mount=Celestron AVX EQ guiding=(none) SOFTWARE: acquisition=Stellarium, APT, processing=DSS, PhotoshopCC, RCAstro, LrC |
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The Rho Ophiuchi cloud is a complex of interstellar clouds associated with different nebulae, particularly dark nebulae which are centered 1° south of the star ρ Ophiuchi, which extends to the constellation Ophiuchus. <Note: the alpha-character "ρ" ("rho") is the 17th character of the Greek alphabet; used to designate the 17th brightest star in the progression of stars contained within the IAU boundaries of the constellation Ophiuchus when listed in order of their brightness in magnitude, from brightest to dimmest.>
The bright, gold-colored star near the center of the image is super-red giant Antares (α Scorpii), known as the "Heart of the Scorpion", the brightest star in the constellation Scorpio. Also, the small white cluster of stars, located directly 'above' Antares is M4, a Globular Cluster known as the "Crab" cluster. At an estimated distance of appx 2.2 light-years, the complex is one of the closest star-forming regions to us here on Earth.
The colors seen in this image are generally not visible to the naked, unaided eye, nor when viewed through a telescope; but, they can be detected using photographic equipment and techniques. The colors result from a mixture of objects and processes. Fine interstellar dust -- illuminated from the front by starlight -- produces blue reflection nebulae. Gaseous clouds whose atoms are excited by ultraviolet starlight produce reddish emission nebulae. Backlit dust clouds block starlight and so appear dark. Antares, one of the brighter stars in our nighttime sky, lights up the yellow-red clouds to the lower right of the image.
Antares is the brightest star in the constellation of Scorpio. It has the Bayer designation α Scorpii, which is Latinised to "Alpha Scorpii". Often referred to as "the heart of the scorpion", Antares is flanked by σ Scorpii and τ Scorpii near the center of the constellation. Distinctly reddish when viewed with the naked eye, Antares is a slow irregular variable star that ranges in brightness from an apparent visual magnitude of +0.6 down to +1.6. (Note: the higher the magnitude number, the dimmer the star.) It is on average the fifteenth-brightest star in the night sky.
Classified as spectral type M1.5Iab-Ib, Antares is a red supergiant, a large and evolved (older) massive star and one of the largest stars visible to the naked eye. Its exact size remains uncertain, but if placed at the center of our Solar System, it would extend out to somewhere between the orbits of Mars and Jupiter. Its mass is calculated to be around 12 times that of our Sun. Antares appears as a single star when viewed with the naked eye, but it is actually a binary star system, with its two components called α Scorpii A and α Scorpii B. The brighter of the pair is the red supergiant, while the fainter is a hot main sequence star of magnitude 5.5. They have a projected separation of appx 0.008 ly (or about 49 billion miles).
Antares is the brightest and most evolved stellar member of the Scorpius–Centaurus association, the nearest OB association of stars to our Sun. It is a member of the Upper Scorpius subgroup of the association, which contains thousands of stars with a mean age of 11 million years. Antares is located appx 550 ly from Earth at the rim of the Upper Scorpius, and is illuminating the Rho Ophiuchi cloud complex in its foreground.
The star system Rho Ophiuchi lies at the center of the blue reflection nebula toward the upper left in this image. These star clouds are even more colorful than humans can see, emitting light across the entire electromagnetic spectrum. Because the region is particularly colorful in the visible spectrum, it is a favorite for amateur astronomical imagers.
The bright, gold-colored star near the center of the image is super-red giant Antares (α Scorpii), known as the "Heart of the Scorpion", the brightest star in the constellation Scorpio. Also, the small white cluster of stars, located directly 'above' Antares is M4, a Globular Cluster known as the "Crab" cluster. At an estimated distance of appx 2.2 light-years, the complex is one of the closest star-forming regions to us here on Earth.
The colors seen in this image are generally not visible to the naked, unaided eye, nor when viewed through a telescope; but, they can be detected using photographic equipment and techniques. The colors result from a mixture of objects and processes. Fine interstellar dust -- illuminated from the front by starlight -- produces blue reflection nebulae. Gaseous clouds whose atoms are excited by ultraviolet starlight produce reddish emission nebulae. Backlit dust clouds block starlight and so appear dark. Antares, one of the brighter stars in our nighttime sky, lights up the yellow-red clouds to the lower right of the image.
Antares is the brightest star in the constellation of Scorpio. It has the Bayer designation α Scorpii, which is Latinised to "Alpha Scorpii". Often referred to as "the heart of the scorpion", Antares is flanked by σ Scorpii and τ Scorpii near the center of the constellation. Distinctly reddish when viewed with the naked eye, Antares is a slow irregular variable star that ranges in brightness from an apparent visual magnitude of +0.6 down to +1.6. (Note: the higher the magnitude number, the dimmer the star.) It is on average the fifteenth-brightest star in the night sky.
Classified as spectral type M1.5Iab-Ib, Antares is a red supergiant, a large and evolved (older) massive star and one of the largest stars visible to the naked eye. Its exact size remains uncertain, but if placed at the center of our Solar System, it would extend out to somewhere between the orbits of Mars and Jupiter. Its mass is calculated to be around 12 times that of our Sun. Antares appears as a single star when viewed with the naked eye, but it is actually a binary star system, with its two components called α Scorpii A and α Scorpii B. The brighter of the pair is the red supergiant, while the fainter is a hot main sequence star of magnitude 5.5. They have a projected separation of appx 0.008 ly (or about 49 billion miles).
Antares is the brightest and most evolved stellar member of the Scorpius–Centaurus association, the nearest OB association of stars to our Sun. It is a member of the Upper Scorpius subgroup of the association, which contains thousands of stars with a mean age of 11 million years. Antares is located appx 550 ly from Earth at the rim of the Upper Scorpius, and is illuminating the Rho Ophiuchi cloud complex in its foreground.
The star system Rho Ophiuchi lies at the center of the blue reflection nebula toward the upper left in this image. These star clouds are even more colorful than humans can see, emitting light across the entire electromagnetic spectrum. Because the region is particularly colorful in the visible spectrum, it is a favorite for amateur astronomical imagers.