NGC 1820 | |
---|---|
Observation data (J2000 epoch) | |
Right ascension | 05h 04m 06.0s [1] [2] |
Declination | −67° 16′ 42″ [1] [2] |
Physical characteristics | |
Other designations | ESO 85-SC39 |
Associations | |
Constellation | Dorado |
NGC 1820 (also known as ESO 85-SC39 [3] ) is an open cluster in the Dorado constellation. It is located within the Large Magellanic Cloud. [2] It has a magnitude of 9.0 [4] [5] and was discovered by John Herschel on 2 January 1837. [5]
Dorado is a constellation in the Southern Sky. It was named in the late 16th century and is now one of the 88 modern constellations. Its name refers to the mahi-mahi, which is known as dorado ("golden") in Spanish, although it has also been depicted as a swordfish. Dorado contains most of the Large Magellanic Cloud, the remainder being in the constellation Mensa. The South Ecliptic pole also lies within this constellation.
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 35 or M35, also known as NGC 2168, is a relatively close open cluster of stars in the west of Gemini, at about the declination of the sun when the latter is at June solstice. It was discovered by Philippe Loys de Chéseaux around 1745 and independently discovered by John Bevis before 1750. It is scattered over part of the sky almost the size of the full moon and is 2,970 light-years away. The compact open cluster NGC 2158 lies directly southwest of it.
NGC 2451 is an open cluster in the Puppis constellation, probably discovered by Giovanni Battista Hodierna before 1654 and John Herschel in 1835. In 1994, it was postulated that this was actually two open clusters that lie along the same line of sight. This was confirmed in 1996. The respective clusters are labeled NGC 2451 A and NGC 2451 B, and they are located at distances of 600 and 1,200 light-years, respectively.
NGC 2516 is an open star cluster in the southern sky in the constellation Carina discovered by Abbe Lacaille in 1751-1752. It is also called Southern Beehive or the Sprinter.
NGC 3532, also commonly known as the Pincushion Cluster, Football Cluster, the Black Arrow Cluster and the Wishing Well Cluster, is an open cluster some 405 parsecs from Earth in the constellation Carina. Its population of approximately 150 stars of 7th magnitude or fainter includes seven red giants and seven white dwarfs. On 20 May 1990 it became the first target ever observed by the Hubble Space Telescope. A line from Beta Crucis through Delta Crucis passes somewhat to the north of NGC 3532. The cluster lies between the constellation Crux and the larger but fainter "False Cross" asterism. The 4th-magnitude Cepheid variable star x Carinae appears near the southeast fringes, but it lies between the Sun and the cluster and is not a member of the cluster.
NGC 5822 is an open cluster of stars in the southern constellation of Lupus. It was discovered by English Astronomer John Herschel on July 3, 1836, and lies close to another cluster, NGC 5823, which suggests there may be a physical association.
NGC 290 is an open cluster of stars in the southern constellation of Tucana. This cluster was discovered September 5, 1826, by Scottish astronomer James Dunlop. It lies some 200,000 light years away from the Sun in the Small Magellanic Cloud galaxy. The cluster is an estimated 30–63 million years old and is around 65 light years across.
The Collinder catalogue is a catalogue of 471 open clusters compiled by Swedish astronomer Per Collinder. It was published in 1931 as an appendix to Collinder's paper On structural properties of open galactic clusters and their spatial distribution.
NGC 559 is an open cluster and Caldwell object in the constellation Cassiopeia. It shines at magnitude +9.5. Its celestial coordinates are RA 01h 29.5m, dec +63° 18′. It is located near the open cluster NGC 637, and the bright magnitude +2.2 irregular variable star Gamma Cassiopeiae. The cluster is 7 arcmins across.
NGC 2439 is a sparse open cluster of stars in the constellation Puppis. It has an apparent visual magnitude of 6.9, an angular size of 10 arcminutes, and is visible using a small telescope. This is a young cluster with age estimates in the range of 20–300 million years. It has a tidal radius of approximately 82 light years. No chemically peculiar stars have been found.
NGC 654 is an open cluster in the constellation Cassiopeia. It was discovered by William Herschel in 1787. With apparent magnitude 6.5, it can be observed by binoculars. It is located 2,5° northeast of the star Delta Cassiopeiae. In the same low power field can also be seen the open clusters NGC 663 and NGC 659. It surrounds a 7th magnitude yellowish star, an F5Ia supergiant, which is a possible member of the group.
NGC 1901 is an open cluster in the Dorado Constellation. It has a bright middle and is a little rich, with stars from 7th magnitude downwards. The celestial object was discovered on 30 December 1836 by the British astronomer John Herschel. The cluster is sparsely populated with GAIA data suggesting a membership of around 80 stars. It is considered unlikely it will survive its next pass through the Milky Way’s galactic plane in about 18 million years time.
NGC 1755 is an open star cluster in the Large Magellanic Cloud in the Dorado constellation. It is about 120 light years across and due to its size could be a globular cluster. It has a diameter of 2.6′ and an apparent magnitude of 9.9. It was discovered by James Dunlop in 1826.
NGC 146 is a small open cluster in the constellation Cassiopeia. It was discovered by John Herschel in 1829 using his father's 18.7 inch reflecting telescope.
NGC 299 is an open cluster of stars in the main body of the Small Magellanic Cloud – a nearby dwarf galaxy. It is located in the southern constellation of Tucana, just under 200,000 light years distant from the Sun. The cluster was discovered on August 12, 1834, by English astronomer John Herschel.
NGC 366 is an open cluster located in the constellation Cassiopeia. It was discovered on October 27, 1829, by John Herschel. It was described by Dreyer as a "cluster, small."
NGC 376 is a young open cluster of stars in the southern constellation of Tucana. It was discovered on September 2, 1826, by Scottish astronomer James Dunlop. Dreyer, a Danish/British astronomer, described it as a "globular cluster, bright, small, round." It is irregular in form, with a central spike.
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 6940 is an open cluster in the constellation Vulpecula. It was discovered by William Herschel in 1784. The cluster is nearly a billion years old and it is located 2,500 light years away. It is considered the finest open cluster in the constellation.