The Butterfly Cluster is an open cluster of stars in the southern constellation of Scorpius. Its name derives from the vague resemblance of its shape to a butterfly. The Trumpler classification of II 3 r encodes it is rich in stars, ranks II out of IV for disparateness and greatly mixes bright with faint components. It is 3.5° to the northwest of Messier 7, both north of the tail of Scorpius.
Messier 36 or M36, also known as NGC 1960, is an open cluster of stars in the somewhat northern Auriga constellation. It was discovered by Giovanni Batista Hodierna before 1654, who described it as a nebulous patch. The cluster was independently re-discovered by Guillaume Le Gentil in 1749, then Charles Messier observed it in 1764 and added it to his catalogue. It is about 1,330 pc away from Earth. The cluster is very similar to the Pleiades cluster (M45), and if as far away it would be of similar apparent magnitude.
Messier 48 or M48, also known as NGC 2548, is an open cluster of stars in the equatorial constellation of Hydra. It sits near Hydra's westernmost limit with Monoceros, about 18° 34′ to the east and slightly south of Hydra's brightest star, Alphard. This grouping was discovered by Charles Messier in 1771, but there is no cluster precisely where Messier indicated; he made an error, as he did with M47. The value that he gave for the right ascension matches, however, his declination is off by five degrees. Credit for discovery is sometimes given instead to Caroline Herschel in 1783. Her nephew John Herschel described it as, "a superb cluster which fills the whole field; stars of 9th and 10th to the 13th magnitude – and none below, but the whole ground of the sky on which it stands is singularly dotted over with infinitely minute points".
NGC 381 is an open cluster of stars in the northern constellation of Cassiopeia, located at a distance of approximately 3,120 light-years from the Sun. Credit for the discovery of this cluster was given to Caroline Herschel by her brother William in 1787, although she may never have actually seen it.
NGC 1502 is a young open cluster of approximately 60 stars in the constellation Camelopardalis, discovered by William Herschel on November 3, 1787. It has a visual magnitude of 6.0 and thus is dimly visible to the naked eye. This cluster is located at a distance of approximately 3,500 light years from the Sun, at the outer edge of the Cam OB1 association of co-moving stars, and is likely part of the Orion Arm. The asterism known as Kemble's Cascade appears to "flow" into NGC 1502, but this is just a chance alignment of stars.
IC 1101 is a class S0 supergiant (cD) lenticular galaxy at the center of the Abell 2029 galaxy cluster. It has an isophotal diameter at about 123.65 to 169.61 kiloparsecs. It possesses a diffuse core which is the largest known core of any galaxy to date, and also hosts a supermassive black hole that is one of the largest black holes known. The galaxy is located at 354.0 megaparsecs from Earth. The galaxy was discovered on 19 June 1790, by the British astronomer William Herschel.
Phi Cassiopeiae is a star in the constellation Cassiopeia. φ Cassiopeiae is a multiple star with a combined apparent magnitude of +4.95. The two brightest components are A and C, sometimes called φ1 and φ2 Cas. φ Cas A is an F0 bright supergiant of magnitude 4.95 and φ Cas C is a 7.08 magnitude B6 supergiant at 134".
NGC 288 is a globular cluster in the constellation Sculptor. Its visual appearance was described by John Dreyer in 1888. It is located about 1.8° southeast of the galaxy NGC 253, 37′ north-northeast of the South Galactic Pole, 15′ south-southeast of a 9th magnitude star, and encompassed by a half-circular chain of stars that opens on its southwest side. It can be observed through binoculars. It is not very concentrated and has a well resolved, large 3′ dense core that is surrounded by a much more diffuse and irregular 9′ diameter ring. Peripheral members extend farther outward towards the south and especially southwest.
NGC 637 is an open cluster of stars in the northern constellation of Cassiopeia, positioned about 1.5° to the WNW of the star Epsilon Cassiopeiae. The cluster was discovered on 9 November 1787 by German-born English astronomer William Herschel. It is located in the Perseus Arm of the Milky Way, at a distance of approximately 7.045 kilolight-years from the Sun. The cluster is small but compact, and is readily visible in a small telescope.
NGC 129 is an open cluster in the constellation Cassiopeia. It was discovered by William Herschel in 1788. It is located almost exactly halfway between the bright stars Caph and γ Cassiopeiae. It is large but not dense and can be observed by binoculars, through which the most obvious component is a small triangle of stars of magnitude 8 and 9, located in the center of the cluster.
NGC 1466 is the New General Catalogue designation for a globular cluster in the deep southern constellation of Hydrus. It is located in the outskirts of the Large Magellanic Cloud, which is a satellite galaxy of the Milky Way. The object was discovered November 26, 1834 by English astronomer John Herschel. John Dreyer described it as "pF, pS, iR, glbM, *7 f", meaning "pretty faint, pretty small, irregular round, gradually a little brighter middle, with a 7th magnitude star nearby". When using a small telescope, this is a "faint, small, unresolved and difficult" target with an angular size of 1.9 arc minutes. It has an integrated visual magnitude of 11.4.
NGC 433 is an open cluster in the northern constellation of Cassiopeia, located at a distance of 6,500 light years from the Sun. It was discovered on September 29, 1829 by John Herschel, and was described by John Dreyer as "cluster, small, a little compressed." The cluster is considered on the poor side, with only 12 stars above magnitude 16. It has a linear diameter of 26.3 ly, with around 479 times the mass of the Sun and an age of 65 million years.
NGC 6939 is an open cluster in the constellation Cepheus. It was discovered by William Herschel in 1798. The cluster lies 2/3° northwest from the spiral galaxy NGC 6946. The cluster lies approximately 4,000 light years away and it is over a billion years old.
NGC 5460 is an open cluster in the constellation Centaurus. It is a bright but loose cluster of intermediate age located approximately 2,300 light years away from Earth. It is located nearly 2 degrees east-southeast of Zeta Centauri.
NGC 5617 is an open cluster in the constellation Centaurus. NGC 5617 forms a binary open cluster with Trumpler 22. It lies one degree west-northwest of Alpha Centauri.
NGC 5316 is an open cluster in the constellation Centaurus. It was discovered by James Dunlop in 1826. Located approximately 4,000 light years away from Earth, it is located in the Carina-Sagittarius arm.
NGC 4103 is an open cluster in the constellation Crux. It was discovered by James Dunlop in 1826. It is located approximately 5,000 light years away from Earth, in the Carina-Sagittarius arm.
NGC 6453 is a globular cluster approximately 37,000 light-years away from Earth in the constellation of Scorpius.
NGC 2527 is an open cluster in the constellation Puppis. It was discovered by William Herschel on December 9, 1784. The cluster was also observed by John Herschel on January 7, 1831. He also observed it on February 5, 1837, identifying it as a different object, which was catalogued as NGC 2520. It is a poor cluster and with no central concentration, with Trumpler class III1p.
