One of the twelve constellations Nicolas-Louis de Lacaille, a French astronomer, drew up in the 18th century, and one of many that feature scientific instruments, is Norma, a little constellation in the Southern Celestial Hemisphere between Ara and Lupus. Its name, which translates from Latin as "normal," denotes a right angle. It is variously thought to stand for a rule, a carpenter's square, a set square, or a level. It is still one among the eighty-eight constellations visible today.
Gamma, Delta, Epsilon, and Eta, four of Norma's brightest stars, form a square in the background of faint stars. The brightest star, Gamma2 Normae, has an apparent magnitude of 4.0. Mu With a brightness between a quarter million and one million times that of the Sun, Normae is among the brightest stars ever discovered. There are planets known to exist in four-star systems. Norma is a constellation that is crossed by the Milky Way and has eight open clusters that can be seen with binoculars. One of the largest known galaxy clusters, Abell 3627, also known as the Norma Cluster, is also located in the constellation. The name of the arm, which derives from the constellation Norma, comes from the fact that the Milky Way's Norma Arm passes through it as seen from Earth. |
History
Nicolas-Louis de Lacaille named Norma l'Équerre et la Règle, or "the Square and Rule" in 1751–1752 (Lacaille 1756) after observing and cataloguing 10,000 southern stars during a two–year sojourn at the Cape of Good Hope. In unexplored areas of the Southern Celestial Hemisphere that were obscured from Europe, he created fourteen new constellations. All but one of them recognised the artefacts of the Age of Enlightenment. (Wagman 2003) In his 1756 chart of the southern stars, Lacaille represented the constellations of Norma, Circinus, and Triangulum Australe as a set square and ruler, a compass, and a surveyor's level in a set of draughtsman instruments, respectively. Some astronomers believed he was calling l'Équerre et Médée because the level hung from the point of a triangle.
Nicolas-Louis de Lacaille named Norma l'Équerre et la Règle, or "the Square and Rule" in 1751–1752 (Lacaille 1756) after observing and cataloguing 10,000 southern stars during a two–year sojourn at the Cape of Good Hope. In unexplored areas of the Southern Celestial Hemisphere that were obscured from Europe, he created fourteen new constellations. All but one of them recognised the artefacts of the Age of Enlightenment. (Wagman 2003) In his 1756 chart of the southern stars, Lacaille represented the constellations of Norma, Circinus, and Triangulum Australe as a set square and ruler, a compass, and a surveyor's level in a set of draughtsman instruments, respectively. Some astronomers believed he was calling l'Équerre et Médée because the level hung from the point of a triangle.
Characteristics
Scorpius to the north, Lupus to the northwest, Circinus to the west, Triangulum Australe to the south, and Ara to the east are the planets that border Norma. Its 165.3 square degrees of coverage, or 0.401 percent of the night sky, places it 74th in size among the eighty-eight constellations. The International Astronomical Union chose the three-letter designation "Nor" for the constellation in 1922. (Russell 1922) A polygon with ten segments, established by Belgian astronomer Eugène Delporte in 1930, defines the borders of the recognised constellations. These borders have right ascension coordinates between 15h 12m 13.6119s and 16h 36m 08.3235s in the equatorial coordinate system, and declination coordinates between 42.27° and 60.44°. In the south of latitude 29°N, observers can see the entire constellation.
Scorpius to the north, Lupus to the northwest, Circinus to the west, Triangulum Australe to the south, and Ara to the east are the planets that border Norma. Its 165.3 square degrees of coverage, or 0.401 percent of the night sky, places it 74th in size among the eighty-eight constellations. The International Astronomical Union chose the three-letter designation "Nor" for the constellation in 1922. (Russell 1922) A polygon with ten segments, established by Belgian astronomer Eugène Delporte in 1930, defines the borders of the recognised constellations. These borders have right ascension coordinates between 15h 12m 13.6119s and 16h 36m 08.3235s in the equatorial coordinate system, and declination coordinates between 42.27° and 60.44°. In the south of latitude 29°N, observers can see the entire constellation.
Deep-sky Objects
Main stars - 4
Bayer stars - 13
Stars with planets - 4
Stars brighter than magnitude 3.00 - 0
Stars within 32 Ly - 0
Bordering
constellations
Meteor showers
Gamma Normids - Early March to late March with a peak of mid-March
- NGC 6087 – Open Cluster
- NGC 6067 – Open Cluster
- NGC 6134 – Open Cluster
- NGC 6167 – Open Cluster
- NGC 6115 – Open Cluster
- NGC 6031 – Open Cluster
- NGC 5999 – Open Cluster
- Shapley 1 – Planetary Nebula
- Mz 3 – The Ant Nebula – Supernova
Main stars - 4
Bayer stars - 13
Stars with planets - 4
Stars brighter than magnitude 3.00 - 0
Stars within 32 Ly - 0
Bordering
constellations
- Ara
- Lupus
- Circinus
- Triangulum Australe
- Scorpius
Meteor showers
Gamma Normids - Early March to late March with a peak of mid-March