[Posted to The Sky Searchers astronomy discussion board.]
Telescope: Explore Scientific 102 mm doublet refractor on Twilight-I Alt-Az manual mount. Eyepieces: Meade 5000 82-degree 14mm and TeleVue 7mm Series 1.
2234 - Zuben el Genubi
2339 NGC 6231
0006 Lesath and Shaula
0009 Messier 7 Ptolemy's Cluster
0017 Messier 80 - 47X
0022 Messier 80 - 94X
0026 Messier 4 - no joy.
0032 Messier 22 in Sagittarius
0039 Messier 6 Butterfly Cluster
The tube was wet. So, I packed everything up and put it all on the porch in case I can go out again later this morning before sunrise.
Thanks and Clear Skies,
Mike M.
Zuben el Genubi. Claw of the South. Also now designated Alpha Librae because of the Roman compulsion for Twelves which added Libra to their zodiac and made the Scorpion fold up his claws. In a small telescope, this is an easy double star: two Main Sequence F stars about 76 light years from Earth. For myself, I learned of it at a show at the Hayden Planetarium in the summer of 1969. The other claw is Zuben al Schamali and I never get tired of saying their names.
NGC 6231. An open cluster of about 100 stars mostly traveling together, though of the easily spotted bright pair one is only 15 ly from Earth and not in the group.
"The original New General Catalogue was compiled during the 1880s by John Louis Emil Dreyer using observations from William Herschel and his son John, among others. ... https://en.wikipedia.org/wiki/New_General_Catalogue#Index_Catalogue
"This cluster is estimated to be about 2–7 million years old,[2][3] and is approaching the Solar System at 22 km/s. The cluster and association lie in the neighboring Sagittarius Arm of the Milky Way. Zeta1 Scorpii (spectral type O8 and magnitude 4.71.[7]) is the brightest star in the association, and one of the most radiant stars known in the galaxy.[8] NGC 6231 was used to measure the binary fraction of B-type stars: 52%±8%, indicating that B-type stars are commonly found in binary systems, but not as commonly as in O-type stars.[3]
NGC 6231 also includes three Wolf-Rayet stars: HD 151932, HD 152270,[9] and HD 152408.[10]". Wolf-Rayet stars are considered unstable and likely to go nova at any time. -- https://en.wikipedia.org/wiki/NGC_6231.
Lesath and Shaula are the two stars in the Sting.
Messier 7. Noted by Claudius Ptolemy in the 1st century of our era, it is visible to the naked eye, even in the city under forgiving skies, though not so tonight. It is to the left (East) of Lesath and Shaula. It is an open cluster of about 80 stars, with 20 to 30 easy to tally.
Messier 80 - A globular cluster of several hundred thousand stars packed into a sphere 95 light years in diameter. It is 32,000 light years from Earth. Globular clusters like this orbit the plane of the Milky Way. Current theory is that the disk (as with all "Grand Design" disk galaxies) condensed out of the halo of globular clusters. The Milky Way has about 125 of them now, likely many more earlier, and other galaxies have significantly more globular clusters. In a small telescope, it looks like a roundish patch of lighter gray. It is in the more or less open area between the eastern claw star "Graffias" (gripper) beta Scorpii and Antares in the center of the body. It is fairly easy to find, even on a bad night.
Messier 4 -- No joy. Technically brighter than Messier 80, it is much larger so its light is spread out and it is not always easy to find. I was told, "Messier 4 does not respond well to light pollution."
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Messier 6 - The Butterfly Cluster. Maybe more than 30 of the 120 stars are easy to see at 47X with a 4-inch telescope in the city. Likely 1590 light years from us, it is about 12 ly in diameter. It is only 94 million years old and so it has highly metallic stars with abundant elements more complex than helium.
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