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The Constellation of Ophiuchus

Next to Hercules and standing on Scorpius, you will find the large constellation of Ophiuchus. The brightest star of Ophiuchus is Rasalhague, which means Head of the Snake Charmer and is only a magnitude 2. You can see this constellation, which looks a bit like a misshapen triangle under less than ideal conditions. 
Ophiuchus, the Serpent Bearer, was formerly known as Serpentarius. In mythology, it is associated with the healer Aesculapius, who became so skilled that he was able to bring the dead back to life. To avoid depopulation of the underworld, Jupiter disposed of Aesculapius with a thunderbolt, but relented sufficiently to place him in the sky.
Ophiuchus contains seven Messier objects M9, M10, M12, M14, M19, M62 and M107 - which are all globular clusters of stars. At right ascension 18 hours 28 m, declination 6 degrees 30 m (the upper left hand corner of the constellation) there is an open cluster of stars that is labeled NGC6633. From a catalogue compiled in 1888, called the "New General Catalogue" . An open cluster consists of a large number of stars, although not as dense as a globular cluster. 
M9 (NGC 6333) is the smallest of this group, unresolved except in large instruments. The cluster is found3.5° SE of eta Ophiuchi. It is considered to be about 26,000 light years away. In the same field are two more globular clusters: NGC 6342 (1° SE) and NGC 6356 (1° NE).
M10 (NGC 6254) and M12 (NGC 6218) are nearly identical globular clusters: like tiny explosions of stars with dense cores. M12 is eight degrees north of zeta Ophiuchi and two degrees east. M10 is 2.5 degrees SE of M12, with 30 Ophiuchi in the same field.
M14 (NGC 6402) needs a 20-cm telescope to resolve; it's more condensed than the preceding two and slightly fainter.
M19 (NGC 6273) is another very dense cluster, usually described as "oblate", or egg-shaped. It is about25000 light years away. M19 is seven degrees due east of Antares in Scorpius, or two and a half degrees west of the bright double 36
Ophiuchi (and very slightly north, less than a degree).
M62 (NGC 6266) is six degrees SW of theta Oph (and four degrees south of M19); this is another non-circular globular cluster, a little brighter than M19. (Note: Burnham includes this Messier in Scorpius; nearly all other authorities put it in Ophiuchus.)
M107 (NGC 6171) is the faintest of the bunch and quite small. This is one of those "Messiers" that were added to the original list, for some reason. It's three degrees SSW of zeta Ophiuchi.
B78, the "Pipe Nebula", is a naked eye dark nebula 2° southeast of theta Ophiuchi, in very rich area of the Milky Way.
Barnard's Star is the most rapidly moving star relative to the solar system, and the second closest star to us, at a distance of only 5.91 light years. This is a red dwarf, with a visual magnitude of only 9.5, and consequently not easily found. The star is three degrees due east of beta Ophiuchus. A slight oscillation in both the right ascension and declination of Barnard's Star has led observers to suggest the possibility that one or more planets orbit the star.
In the upper-left, less than 2 degrees north- east of Beta, is IC-4665, a beautiful open cluster that can be seen very well with ordinary binoculars.



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Last Monday, Jan. 10, Parke Kunkle was just an ordinary astronomy instructor in Minnesota. But then he talked to Bill Ward of the Minneapolis Star Tribune, and let him know about the real precession of the Earth. Over a week later, Kunkle is now infamous as the man who shook up the cosmos.
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Title: On the Distance to the Ophiuchus Star-Forming Region
Authors: Eric E. Mamajek
(Version v2)

The Ophiuchus molecular cloud complex has produced in Lynds 1688 the richest known embedded cluster within ~300 pc of the Sun. Unfortunately, distance estimates to the Oph complex vary by nearly ~40% (~120-165 pc). Here I calculate a new independent distance estimate of 135 ± 8 pc to this benchmark star-forming region based on Hipparcos trigonometric parallaxes to stars illuminating reflection nebulosity in close proximity to Lynds 1688. Combining this value with recent distance estimates from reddening studies suggests a consensus distance of 139 +- 6 pc (4% error), situating it within ~11 pc of the centroid of the ~5 Myr old Upper Sco OB subgroup of Sco OB2 (145 pc). The velocity vectors for Oph and Upper Sco are statistically indistinguishable within ~1 km/s in each vector component. Both Oph and Upper Sco have negligible motion (<1 km/s) in the Galactic vertical direction with respect to the Local Standard of Rest, which is inconsistent with the young stellar groups having formed via the high velocity cloud impact scenario.

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Ophiuchus Star-Forming Region
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Title: On the Distance to the Ophiuchus Star-Forming Region
Authors: Eric E. Mamajek

The Ophiuchus molecular cloud complex has produced in Lynds 1688 the richest known embedded cluster within ~300 pc of the Sun. Unfortunately, distance estimates to the Oph complex vary by nearly ~40% (~120-165 pc). Here I calculate a new independent distance estimate of 135 ± 8 pc to this benchmark star-forming region based on Hipparcos trigonometric parallaxes to stars illuminating reflection nebulosity in close proximity to Lynds 1688. Combining this value with recent distance estimates from reddening studies suggests a consensus distance of 139 ± 6 pc (4% error), situating it within ~11 pc of the centroid of the ~5 Myr old Upper Sco OB subgroup of Sco OB2 (145 pc). The velocity vectors for Oph and Upper Sco are statistically indistinguishable within ~1 km/s in each vector component. Both Oph and Upper Sco have negligible motion (<1 km/s) in the Galactic vertical direction with respect to the Local Standard of Rest, which is inconsistent with the young stellar groups having formed via the high velocity cloud impact scenario.

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Ophiuchus
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A 13th sign has emerged in the 12-sign zodiac thanks to tiny shifts or wobbles in the Earth's rotation around the Sun, an Australian astronomer said.

"Basically, the Sun's apparent path has moved since 3000 years ago when astrology was born" - John Shobbrook, the manager of Australia National University's Siding Spring observatory.

The new sign is Ophiuchus, or the Serpent Bearer, which falls between November 30 and December 18, placing it between Scorpio and Sagittarius.

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