Rho-Ophiuchus Antares Region

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The Rho-Antares region — a wide-field mosaic in Scorpius, shot from Kitt Peak National Observatory. Credit line: Jay Ballauer, Phil Jones, and Adam Block.

Location: Kitt Peak National Observatory near Tucson, Arizona

Date: June 2, 2005

Seeing: 3/10

Transparency: 9/10

Temperature: 52 degrees F (-20 degrees C on camera)

Scope/Mount: Tak FSQ-106 @ f/5 and Paramount ME

Camera: SBIG STL-11000M astro CCD camera

Exposure Info: Two frame mosaic, RGB image; 20:20:30 RGB for each frame (10 minute subexposures all unbinned), processed with synthetic luminance

Processing Information: Calibration (darks, bias, flats), registration, gradient removal, and RGB channel combine in MaxIm DL 4 (mean combine). LRGB combine, mosaic stitching, cropping, color balance, levels/curves, sharpening, and noise removal in Photoshop CS.

Exposure Notes: String used on the front of the aperture to give the diffraction spikes on the stars. Data was taken by Jay Ballauer, Phil Jones, and Adam Block. Image processing done by Jay Ballauer. Special thanks to Adam Block for hosting Phil and I at the Advanced Observer's Program atop Kitt Peak. Likewise, thanks to the Three Rivers Foundation and Dr. Fred Koch for sponsoring the trip.

About this Object

This area of Scorpius produces the prettiest photographs! The bright yellow star Antares, the heart of the Scorpion, produces a curious yellow nebulosity; very rare. That would ordinarily be pretty enough but many other colorful objects adorn this view.

Three areas of blue nebulosity appear, most notably around the triple star system of Rho Ophiuchi at the upper right. Another area of blue nebulosity surrounds the triple star system of 22 Scorpii, just above Antares. Between the two triple star systems is IC 4603, itself a pretty blue nebula. Red nebulosity also appears in the area around Sigma Scorpii at the upper right and below Antares itself. The great M4 globular cluster appears just to the right of Antares and another smaller globular, NGC 6144, can be seen right in the middle of everything else. And all this is covered with the dust of dark nebula, such as Barnard 42 in the upper left.

Therefore, the image shows every type of nebulosity imaginable; red hydrogen emission nebulae, blue and yellow reflection nebulae, and dark nebulae. In total, this area of colorful dust is quite extraordinary!

🤖 AI-drafted · unverified

What it is: The Rho Ophiuchi cloud complex, together with the nearby red supergiant Antares, forms one of the most colorful regions in the sky, straddling the border of Ophiuchus and Scorpius.
Constellation: Ophiuchus / Scorpius border
Distance: ~460 ly (Rho Oph cloud); ~550 ly (Antares)
Apparent magnitude: 1.06 (Antares)
Angular size: several degrees (complex)
Coordinates: Antares: RA 16h 25m, Dec -23° 27′

This summary was generated by an AI assistant from general astronomical references, not from Jay's own notes on this specific image. Treat every detail above as a starting point for research, not settled fact.