Norma (constellation)
   HOME

TheInfoList



OR:

Norma is a small constellation in the
Southern Celestial Hemisphere The southern celestial hemisphere, also called the Southern Sky, is the southern half of the celestial sphere; that is, it lies south of the celestial equator. This arbitrary sphere, on which seemingly fixed stars form constellations, appears ...
between
Ara ARA may refer to: Media and the arts * American-Romanian Academy of Arts and Sciences * '' Artistička Radna Akcija'', compilation album released in former Yugoslavia * Associate of the Royal Academy, denoting membership in the British Royal Aca ...
and
Lupus Lupus, technically known as systemic lupus erythematosus (SLE), is an autoimmune disease in which the body's immune system mistakenly attacks healthy tissue in many parts of the body. Symptoms vary among people and may be mild to severe. Comm ...
, one of twelve drawn up in the 18th century by French
astronomer An astronomer is a scientist in the field of astronomy who focuses their studies on a specific question or field outside the scope of Earth. They observe astronomical objects such as stars, planets, natural satellite, moons, comets and galaxy, g ...
Nicolas-Louis de Lacaille Abbé Nicolas-Louis de Lacaille (; 15 March 171321 March 1762), formerly sometimes spelled de la Caille, was a kingdom of France, French astronomer and geodesist who named 14 out of the IAU designated constellations, 88 constellations. From 1750 ...
and one of several depicting scientific instruments. Its name is
Latin Latin (, or , ) is a classical language belonging to the Italic branch of the Indo-European languages. Latin was originally a dialect spoken in the lower Tiber area (then known as Latium) around present-day Rome, but through the power of the ...
for
normal Normal(s) or The Normal(s) may refer to: Film and television * ''Normal'' (2003 film), starring Jessica Lange and Tom Wilkinson * ''Normal'' (2007 film), starring Carrie-Anne Moss, Kevin Zegers, Callum Keith Rennie, and Andrew Airlie * ''Norma ...
, referring to a
right angle In geometry and trigonometry, a right angle is an angle of exactly 90 Degree (angle), degrees or radians corresponding to a quarter turn (geometry), turn. If a Line (mathematics)#Ray, ray is placed so that its endpoint is on a line and the ad ...
, and is variously considered to represent a
rule Rule or ruling may refer to: Education * Royal University of Law and Economics (RULE), a university in Cambodia Human activity * The exercise of political or personal control by someone with authority or power * Business rule, a rule perta ...
, a carpenter's square, a
set square A set square or triangle (American English) is an object used in engineering and technical drawing, with the aim of providing a straightedge at a right angle or other particular planar angle to a baseline. The simplest form of set square is a ...
or a
level Level or levels may refer to: Engineering *Level (instrument), a device used to measure true horizontal or relative heights *Spirit level, an instrument designed to indicate whether a surface is horizontal or vertical *Canal pound or level *Regr ...
. It remains one of the
88 modern constellations In contemporary astronomy, 88 constellations are recognized by the International Astronomical Union (IAU). Each constellation is a region of the sky, bordered by arcs of right ascension and declination. Together they cover the celestial sphere ...
. Four of Norma's brighter stars—Gamma, Delta, Epsilon and Eta—make up a square in the field of faint stars. Gamma2 Normae is the brightest star with an
apparent magnitude Apparent magnitude () is a measure of the brightness of a star or other astronomical object observed from Earth. An object's apparent magnitude depends on its intrinsic luminosity, its distance from Earth, and any extinction of the object's li ...
of 4.0.
Mu Normae μ Normae, Latinised as Mu Normae, is a blue supergiant star of spectral type O9.7 Iab, located in the constellation of Norma. It shines as bright as 339,000 suns and is weighs 40 solar masses. It varies in visual magnitude between 4.87 ...
is one of the most luminous stars known, with a luminosity between a quarter million and one million times that of the Sun. Four star systems are known to harbour planets. The
Milky Way The Milky Way is the galaxy that includes our Solar System, with the name describing the galaxy's appearance from Earth: a hazy band of light seen in the night sky formed from stars that cannot be individually distinguished by the naked eye ...
passes through Norma, and the constellation contains eight
open cluster An open cluster is a type of star cluster made of up to a few thousand stars that were formed from the same giant molecular cloud and have roughly the same age. More than 1,100 open clusters have been discovered within the Milky Way galaxy, and ...
s visible to observers with binoculars. The constellation also hosts Abell 3627, also called the
Norma Cluster The Norma Cluster (ACO 3627 or Abell 3627) is a rich cluster of galaxies located near the center of the Great Attractor; it is about distant. Although it is both nearby and bright, it is difficult to observe because it is located in the Zone of ...
, one of the most massive
galaxy cluster A galaxy cluster, or a cluster of galaxies, is a structure that consists of anywhere from hundreds to thousands of galaxies that are bound together by gravity, with typical masses ranging from 1014 to 1015 solar masses. They are the second-l ...
s known. From the perspective of an observer on Earth, the Norma Arm of the Milky Way passes through the constellation Norma, and it's from the constellation that the arm's name is derived.


History

Norma was introduced in 1751–52 by
Nicolas-Louis de Lacaille Abbé Nicolas-Louis de Lacaille (; 15 March 171321 March 1762), formerly sometimes spelled de la Caille, was a kingdom of France, French astronomer and geodesist who named 14 out of the IAU designated constellations, 88 constellations. From 1750 ...
with the French name ''l’Équerre et la Règle'', "the Square and Rule", after he had observed and catalogued 10,000 southern stars during a two-year stay at the
Cape of Good Hope The Cape of Good Hope ( af, Kaap die Goeie Hoop ) ;''Kaap'' in isolation: pt, Cabo da Boa Esperança is a rocky headland on the Atlantic coast of the Cape Peninsula in South Africa. A common misconception is that the Cape of Good Hope is t ...
. He devised 14 new constellations in uncharted regions of the
Southern Celestial Hemisphere The southern celestial hemisphere, also called the Southern Sky, is the southern half of the celestial sphere; that is, it lies south of the celestial equator. This arbitrary sphere, on which seemingly fixed stars form constellations, appears ...
not visible from Europe. All but one honoured instruments that symbolised the
Age of Enlightenment The Age of Enlightenment or the Enlightenment; german: Aufklärung, "Enlightenment"; it, L'Illuminismo, "Enlightenment"; pl, Oświecenie, "Enlightenment"; pt, Iluminismo, "Enlightenment"; es, La Ilustración, "Enlightenment" was an intel ...
. Lacaille portrayed the constellations of Norma,
Circinus Circinus is a small, faint constellation in the southern sky, first defined in 1756 by the French astronomer Nicolas-Louis de Lacaille. Its name is Latin for compass (drawing tool), compass, referring to the Technical drawing, drafting tool used ...
and
Triangulum Australe Triangulum Australe is a small constellation in the far Southern Celestial Hemisphere. Its name is Latin for "the southern triangle", which distinguishes it from Triangulum in the northern sky and is derived from the acute, almost equilateral p ...
, respectively, as a set square and ruler, a compass, and a surveyor's level in a set of draughtsman instruments, in his 1756 map of the southern stars. The level was dangling from the apex of a triangle, leading some astronomers to conclude he was renaming ''l’Équerre et la Règle'' to "le Niveau", "the level". In any case, the constellation's name had been shortened and Latinised by Lacaille to ''Norma'' by 1763.


Characteristics

Norma is bordered by
Scorpius Scorpius is a zodiac constellation located in the Southern celestial hemisphere, where it sits near the center of the Milky Way, between Libra to the west and Sagittarius to the east. Scorpius is an ancient constellation that pre-dates the Gre ...
to the north,
Lupus Lupus, technically known as systemic lupus erythematosus (SLE), is an autoimmune disease in which the body's immune system mistakenly attacks healthy tissue in many parts of the body. Symptoms vary among people and may be mild to severe. Comm ...
to the northwest, Circinus to the west, Triangulum Australe to the south and Ara to the east. Covering 165.3 square degrees and 0.401% of the night sky, it ranks 74th of the 88 constellations in size. The three-letter abbreviation for the constellation, as adopted by the
International Astronomical Union The International Astronomical Union (IAU; french: link=yes, Union astronomique internationale, UAI) is a nongovernmental organisation with the objective of advancing astronomy in all aspects, including promoting astronomical research, outreac ...
in 1922, is "Nor". The official constellation boundaries, as set by Belgian astronomer
Eugène Delporte Eugene is a common male given name that comes from the Greek εὐγενής (''eugenēs''), "noble", literally "well-born", from εὖ (''eu''), "well" and γένος (''genos''), "race, stock, kin".equatorial coordinate system The equatorial coordinate system is a celestial coordinate system widely used to specify the positions of celestial objects. It may be implemented in spherical or rectangular coordinates, both defined by an origin at the centre of Earth, a fund ...
, the
right ascension Right ascension (abbreviated RA; symbol ) is the angular distance of a particular point measured eastward along the celestial equator from the Sun at the March equinox to the (hour circle of the) point in question above the earth. When paired w ...
coordinates of these borders lie between and , while the
declination In astronomy, declination (abbreviated dec; symbol ''δ'') is one of the two angles that locate a point on the celestial sphere in the equatorial coordinate system, the other being hour angle. Declination's angle is measured north or south of the ...
coordinates are between −42.27° and −60.44°. The whole constellation is visible to observers south of latitude 29°N.


Features


Stars

Lacaille charted and designated ten stars with the
Bayer designation A Bayer designation is a stellar designation in which a specific star is identified by a Greek or Latin letter followed by the genitive form of its parent constellation's Latin name. The original list of Bayer designations contained 1,564 stars. ...
s Alpha through to Mu in 1756, however his Alpha Normae was transferred into Scorpius and left unnamed by
Francis Baily Francis Baily (28 April 177430 August 1844) was an English astronomer. He is most famous for his observations of "Baily's beads" during a total eclipse of the Sun. Baily was also a major figure in the early history of the Royal Astronomical S ...
, before being named N Scorpii by
Benjamin Apthorp Gould Benjamin Apthorp Gould (September 27, 1824 – November 26, 1896) was a pioneering American astronomer. He is noted for creating the ''Astronomical Journal'', discovering the Gould Belt, and for founding of the Argentine National Observatory and ...
, who felt its brightness warranted recognition. Though Beta Normae was depicted on his star chart, it was inadvertently left out of Lacaille's 1763 catalogue, was likewise transferred to Scorpio by Baily and named H Scorpii by Gould. Norma's brightest star, Gamma2 Normae, is only of
magnitude Magnitude may refer to: Mathematics *Euclidean vector, a quantity defined by both its magnitude and its direction *Magnitude (mathematics), the relative size of an object *Norm (mathematics), a term for the size or length of a vector *Order of ...
4.0. Overall, there are 44 stars within the constellation's borders brighter than or equal to
apparent magnitude Apparent magnitude () is a measure of the brightness of a star or other astronomical object observed from Earth. An object's apparent magnitude depends on its intrinsic luminosity, its distance from Earth, and any extinction of the object's li ...
6.5. The four main stars—Gamma, Delta, Epsilon and Eta—make up a square in this region of faint stars. Gamma1 and Gamma2 Normae are an
optical double In observational astronomy, a double star or visual double is a pair of stars that appear close to each other as viewed from Earth, especially with the aid of optical telescopes. This occurs because the pair either forms a binary star (i.e. a bi ...
, and not a true
binary star A binary star is a system of two stars that are gravitationally bound to and in orbit around each other. Binary stars in the night sky that are seen as a single object to the naked eye are often resolved using a telescope as separate stars, in wh ...
system. Located 129 ± 1
light-year A light-year, alternatively spelled light year, is a large unit of length used to express astronomical distances and is equivalent to about 9.46 trillion kilometers (), or 5.88 trillion miles ().One trillion here is taken to be 1012 ...
s away from Earth, Gamma2 Normae is a yellow giant of
spectral type In astronomy, stellar classification is the classification of stars based on their stellar spectrum, spectral characteristics. Electromagnetic radiation from the star is analyzed by splitting it with a Prism (optics), prism or diffraction grati ...
G8III around 2 to 2.5  times as massive as the Sun. It has swollen to a diameter 10 times that of the Sun and shines with 45 times the Sun's luminosity. It also is half of a close optical double, with a magnitude 10 companion star related by line of sight only. Gamma1 Normae is a yellow-white supergiant, located much further away at around 1500 light-years from Earth. Epsilon Normae is a
spectroscopic binary A binary star is a system of two star, stars that are gravity, gravitationally bound to and in orbit around each other. Binary stars in the night sky that are seen as a single object to the naked eye are often resolved using a telescope as separa ...
, with two blue-white main sequence stars of almost equal mass and spectral type (B3V) orbiting each other every 3.26 days. There is a third star separated by 22 arcseconds, which has a magnitude of 7.5 and is likely a smaller B-type main sequence star of spectral type B9V. The system is 530 ± 20 light-years distant from Earth,
Eta Normae Eta Normae, Latinized from η Normae, is a single star in the southern constellation of Norma. It is visible to the naked eye as a faint, yellow-hued star with an apparent visual magnitude of 4.65. The distance to this star is about 219 ...
is a yellow giant of spectral type G8III with an apparent magnitude of 4.65. It shines with a
luminosity Luminosity is an absolute measure of radiated electromagnetic power (light), the radiant power emitted by a light-emitting object over time. In astronomy, luminosity is the total amount of electromagnetic energy emitted per unit of time by a st ...
approximately 66 times that of the Sun. Iota1 Normae is a multiple star system. The AB (mag 5.2 and 5.76) pair orbit each other with a period of 26.9 years; they are 2.77 and 2.71 times as massive as the Sun respectively. The pair are 128 ± 6 light-years distant from Earth. A third component is a yellow main sequence star of spectral type G8V with an apparent magnitude of 8.02.
Mu Normae μ Normae, Latinised as Mu Normae, is a blue supergiant star of spectral type O9.7 Iab, located in the constellation of Norma. It shines as bright as 339,000 suns and is weighs 40 solar masses. It varies in visual magnitude between 4.87 ...
is a remote blue supergiant of spectral type O9.7Iab, one of the most luminous stars known, but is partially obscured by distance and
cosmic dust Cosmic dust, also called extraterrestrial dust, star dust or space dust, is dust which exists in outer space, or has fallen on Earth. Most cosmic dust particles measure between a few molecules and 0.1 mm (100 micrometers). Larger particles are c ...
. Uncertainties regarding its distance leave open the possibility that Mu Normae could be between 250,000 and one million times as luminous and up to 60 times as massive as the Sun, though it is more likely to have around 500,000 times the Sun's luminosity and 40 times its mass. It is suspected of being an
Alpha Cygni variable Alpha Cygni variables are variable stars which exhibit non-radial pulsations, meaning that some portions of the stellar surface are contracting at the same time other parts expand. They are supergiant stars of spectral types B or A. Variations in ...
, with a magnitude range of 4.87–4.98. QU Normae is another hot blue-white star that is a variable, ranging from magnitude 5.27 to 5.41 over 4.8 days. Lying near
Eta Normae Eta Normae, Latinized from η Normae, is a single star in the southern constellation of Norma. It is visible to the naked eye as a faint, yellow-hued star with an apparent visual magnitude of 4.65. The distance to this star is about 219 ...
is R Normae, a
Mira variable Mira variables (named for the prototype star Mira) are a class of pulsating stars characterized by very red colours, pulsation periods longer than 100 days, and amplitudes greater than one magnitude in infrared and 2.5 magnitude at visual wavelen ...
. Its visual magnitude range is 6.5–13.9 and its average period is 507.5 days. Located halfway between Eta Normae and Gamma Circini is T Normae, another Mira variable. It ranges from magnitude 6.2 to 13.6, with a period of 244 days.
S Normae S Normae (S Nor) is a yellow supergiant variable star in the constellation Norma. It is the brightest member of the open cluster NGC 6087. S Normae is a Classical Cepheid variable with a visual magnitude range of 6.12 to 6.77 and a pe ...
is a well-known
Cepheid variable A Cepheid variable () is a type of star that pulsates radially, varying in both diameter and temperature and producing changes in brightness with a well-defined stable period and amplitude. A strong direct relationship between a Cepheid varia ...
with a magnitude range of 6.12–6.77 and a period of 9.75411 days. It is located at the centre of the
open cluster An open cluster is a type of star cluster made of up to a few thousand stars that were formed from the same giant molecular cloud and have roughly the same age. More than 1,100 open clusters have been discovered within the Milky Way galaxy, and ...
NGC 6087. It is a yellow-white supergiant of spectral type F8-G0Ib that is 6.3 times as massive as the Sun. A binary, it has a 2.4 
solar mass The solar mass () is a standard unit of mass in astronomy, equal to approximately . It is often used to indicate the masses of other stars, as well as stellar clusters, nebulae, galaxies and black holes. It is approximately equal to the mass ...
() companion that is a blue-white main sequence star of spectral type B9.5V. A binary system composed of two wolf-rayet stars, colloquially called
Apep Apep, also spelled Apepi or Aapep, ( Ancient Egyptian: ; Coptic: Erman, Adolf, and Hermann Grapow, eds. 1926–1953. ''Wörterbuch der aegyptischen Sprache im Auftrage der deutschen Akademien''. 6 vols. Leipzig: J. C. Hinrichs'schen Buch ...
, has been identified as a possible progenitor of a long gamma-ray burst. Located around 8000 light-years distant, it would be the first such in the Milky Way. IM Normae is one of only ten
recurrent nova A nova (plural novae or novas) is a transient astronomical event that causes the sudden appearance of a bright, apparently "new" star (hence the name "nova", which is Latin for "new") that slowly fades over weeks or months. Causes of the dramati ...
e known in the
Milky Way The Milky Way is the galaxy that includes our Solar System, with the name describing the galaxy's appearance from Earth: a hazy band of light seen in the night sky formed from stars that cannot be individually distinguished by the naked eye ...
. It has erupted in 1920 and 2002, reaching magnitude 8.5 from a baseline of 18.3. It was poorly monitored after the first eruption, so it is possible that it erupted in between. Norma hosts two faint
R Coronae Borealis variable An R Coronae Borealis variable (abbreviated RCB, R CrB) is an eruptive variable star that varies in luminosity in two modes, one low amplitude pulsation (a few tenths of a magnitude), and one irregular, unpredictably-sudden fading by 1 to 9 ma ...
stars of magnitude 10— RT Normae and RZ Normae—rare degenerate stars thought to have formed from the merger of two
white dwarf A white dwarf is a stellar core remnant composed mostly of electron-degenerate matter. A white dwarf is very dense: its mass is comparable to the Sun's, while its volume is comparable to the Earth's. A white dwarf's faint luminosity comes fro ...
s that fade by several magnitudes periodically as they eject large amounts of carbon dust. A faint object of magnitude 16, QV Normae is a high mass
X-ray binary X-ray binaries are a class of binary stars that are luminous in X-rays. The X-rays are produced by matter falling from one component, called the ''donor'' (usually a relatively normal star), to the other component, called the ''accretor'', whi ...
star system 15,000–20,000 light-years distant from Earth. It is composed of a
neutron star A neutron star is the collapsed core of a massive supergiant star, which had a total mass of between 10 and 25 solar masses, possibly more if the star was especially metal-rich. Except for black holes and some hypothetical objects (e.g. white ...
orbiting a blue-white supergiant approximately 20 times as massive as the Sun. The
stellar wind A stellar wind is a flow of gas ejected from the upper atmosphere of a star. It is distinguished from the bipolar outflows characteristic of young stars by being less collimated, although stellar winds are not generally spherically symmetric. D ...
from the more massive star is drawn to the magnetic poles of the neutron star, forming an accretion column and producing X-rays. Located 19,000 light-years away, QX Normae is an active low mass X ray binary composed of a neutron star and its companion star that is smaller and cooler than the Sun. The neutron star is 1.74 ± 0.14 times as massive as the Sun, yet its radius is a mere 9.3 ± 1.0 km. 1E161348-5055 is a neutron star found in the centre of RCW103
supernova remnant A supernova remnant (SNR) is the structure resulting from the explosion of a star in a supernova. The supernova remnant is bounded by an expanding shock wave, and consists of ejected material expanding from the explosion, and the interstellar mat ...
. A periodic
X-ray An X-ray, or, much less commonly, X-radiation, is a penetrating form of high-energy electromagnetic radiation. Most X-rays have a wavelength ranging from 10  picometers to 10  nanometers, corresponding to frequencies in the range 30&nb ...
source with a period of 6.67 hours, it is approximately 2000 years old and 10,000 light-years away from Earth. It is unusual in that it is spinning much too slowly for its young age, behaving instead like a multi-million-year-old star. SGR J1550-5418 is a
soft gamma repeater A soft gamma repeater (SGR) is an astronomical object which emits large bursts of gamma-rays and X-rays at irregular intervals. It is conjectured that they are a type of magnetar or, alternatively, neutron stars with fossil disks around them. His ...
(SGR)—a
magnetar A magnetar is a type of neutron star with an extremely powerful magnetic field (∼109 to 1011 T, ∼1013 to 1015 G). The magnetic-field decay powers the emission of high-energy electromagnetic radiation, particularly X-rays and gamma rays.War ...
that is emitting gamma ray flares, located some 30,000 light-years distant from Earth. The rotation period, of approximately 2.07 seconds, is the fastest yet observed for a magnetar. XTE J1550-564 is another X-ray binary, this time composed of a large black hole around 10 times as massive as the Sun and a cool orange donor star. The black hole is a
microquasar A microquasar, the smaller version of a quasar, is a compact region surrounding a stellar black hole with a mass several times that of its companion star. The matter being pulled from the companion star forms an accretion disk around the black hol ...
, firing off jets of material most likely from its accretion disk. Four star systems are known to harbour planets. HD 330075 is a sunlike star around 164 light-years distant that is orbited by a
hot Jupiter Hot Jupiters (sometimes called hot Saturns) are a class of gas giant exoplanets that are inferred to be physically similar to Jupiter but that have very short orbital periods (). The close proximity to their stars and high surface-atmosphere temp ...
every 3.4 days. Announced in 2004, it was the first planet discovered by the
HARPS The High Accuracy Radial Velocity Planet Searcher (HARPS) is a high-precision echelle planet-finding spectrograph installed in 2002 on the ESO's 3.6m telescope at La Silla Observatory in Chile. The first light was achieved in February 2003. H ...
spectrograph An optical spectrometer (spectrophotometer, spectrograph or spectroscope) is an instrument used to measure properties of light over a specific portion of the electromagnetic spectrum, typically used in spectroscopic analysis to identify mate ...
. HD 148156 is a star 168 ± 7 light-years distant. Slightly larger and hotter than the Sun, it was found to have a roughly Jupiter-size planet with an orbital period of 2.8 years. HD 143361 is a binary star system composed of a sunlike star and a faint red dwarf separated by 30.9 AU. A planet roughly triple the mass of Jupiter orbits the brighter star every 1057± 20 days.
HD 142415 HD 142415 is a single star in the southern constellation of Norma, positioned next to the southern constellation border with Triangulum Australe and less than a degree to the west of NGC 6025. With an apparent visual magnitude of 7.33 ...
is approximately 113 light-years distant and has a Jupiter-sized planet with an orbital period of around 386 days.


Deep-sky objects

Due to its location on the Milky Way, this constellation contains many
deep-sky object A deep-sky object (DSO) is any astronomical object that is not an individual star or Solar System object (such as Sun, Moon, planet, comet, etc.). The classification is used for the most part by amateur astronomers to denote visually observed fa ...
s such as
star cluster Star clusters are large groups of stars. Two main types of star clusters can be distinguished: globular clusters are tight groups of ten thousand to millions of old stars which are gravitationally bound, while open clusters are more loosely clust ...
s, including eight
open cluster An open cluster is a type of star cluster made of up to a few thousand stars that were formed from the same giant molecular cloud and have roughly the same age. More than 1,100 open clusters have been discovered within the Milky Way galaxy, and ...
s visible through binoculars.
NGC 6087 NGC 6087 (also known as Caldwell 89 or the S Normae Cluster) is an open cluster of 40 or moreBurnham's ''Celestial Handbook'' gives the number 40, though other studies go as high as 349; see Stephen James O'Meara, ''The Caldwell Objects'', Cambri ...
is the brightest of the
open cluster An open cluster is a type of star cluster made of up to a few thousand stars that were formed from the same giant molecular cloud and have roughly the same age. More than 1,100 open clusters have been discovered within the Milky Way galaxy, and ...
s in Norma with a magnitude of 5.4. It lies in the southeastern corner of the constellation between Alpha Centauri and
Zeta Arae Zeta Arae (ζ Ara, ζ Arae) is the third-brightest star in the southern constellation Ara. The apparent visual magnitude of this star is 3.1, which can be seen from suburban skies in the southern hemisphere. From the parallax measurements ...
. Thought to be around 100 million years old, it is about 3300 light-years away and is around 14 light-years in diameter. Its brightest member is the
Cepheid variable A Cepheid variable () is a type of star that pulsates radially, varying in both diameter and temperature and producing changes in brightness with a well-defined stable period and amplitude. A strong direct relationship between a Cepheid varia ...
S Normae S Normae (S Nor) is a yellow supergiant variable star in the constellation Norma. It is the brightest member of the open cluster NGC 6087. S Normae is a Classical Cepheid variable with a visual magnitude range of 6.12 to 6.77 and a pe ...
. A rich background star field makes it less distinct, though around 36 member stars are visible though a 10 cm telescope at 150x magnification. Located 0.4° north of
Kappa Normae Kappa Normae, Latinized from κ Normae, is a solitary, yellow hued star in the southern constellation of Norma. Its apparent magnitude is 4.94, which is bright enough to be faintly visible to the naked eye. Based upon an annual paralla ...
is
NGC 6067 NGC 6067 is an open cluster in the constellation Norma. It is located to the north of Kappa Normae, with an angular diameter of 12. Visible to the naked eye in dark skies, it is best observed with binoculars or a small telescope, and a 12-inch ...
, which has an integrated magnitude of 5.6 though it is indistinct as it lies in a rich star field. It is thought to be around 102 million years old, and contain 891 solar masses. Two Cepheid variables— QZ Normae and
V340 Normae V34, or similar, may refer to: * Brazilian corvette ''Barroso'' (V34) * Fokker V.34, a German prototype fighter aircraft of World War I * V.34, a telecommunications recommendation of the ITU-T {{Letter-NumberCombDisambig ...
—have been identified as members of the cluster. Fainter open clusters include NGC 6134 with a combined magnitude of 7.2 and located 4000 light-years away from Earth, the spread-out
NGC 6167 NGC 6167 is an open cluster in the constellation of Norma, viewed from Earth it has an apparent magnitude Apparent magnitude () is a measure of the brightness of a star or other astronomical object observed from Earth. An object's apparent ...
of magnitude 6.7, NGC 6115 near Gamma Normae, NGC 6031 and NGC 5999. Located around 4900 light-years distant is
Shapley 1 Shapley 1 (''Sp 1'' or ''PLN 329+2.1'') is an annular planetary nebula in the constellation of Norma with a magnitude of +12.6. As viewed from Earth, it is peculiar in that it seems to be a non- bipolar, torus-shaped planetary nebula. However, ...
(or PK 329+02.1), a
planetary nebula A planetary nebula (PN, plural PNe) is a type of emission nebula consisting of an expanding, glowing shell of ionized gas ejected from red giant stars late in their lives. The term "planetary nebula" is a misnomer because they are unrelated to ...
better known as the ''Fine-Ring Nebula''. Appearing ring-shaped, it is thought that it actually is cylindrical and oriented directly at Earth. Around 8700 years old, it lies about five degrees west-northwest of Gamma1 Normae. Its integrated magnitude is 13.6 and its mean
surface brightness In astronomy, surface brightness (SB) quantifies the apparent brightness or flux density per unit angular area of a spatially extended object such as a galaxy or nebula, or of the night sky background. An object's surface brightness depends on it ...
is 13.9. The central star is a
white dwarf A white dwarf is a stellar core remnant composed mostly of electron-degenerate matter. A white dwarf is very dense: its mass is comparable to the Sun's, while its volume is comparable to the Earth's. A white dwarf's faint luminosity comes fro ...
of magnitude 14.03. Mz 1 is a bipolar planetary nebula, thought to be an hourglass shape tilted at an angle to observers on Earth, some 3500 light-years distant.
Mz 3 Mz 3 (Menzel 3) is a young bipolar planetary nebula (PN) in the constellation Norma that is composed of a bright core and four distinct high-velocity outflows that have been named lobes, columns, rays, and chakram. These nebulosities are descri ...
—known as the Ant Nebula as it resembles an ant—has a complex appearance, with at least four outflow jets and two large lobes visible. Approximately 200 million light-years from Earth with a
redshift In physics, a redshift is an increase in the wavelength, and corresponding decrease in the frequency and photon energy, of electromagnetic radiation (such as light). The opposite change, a decrease in wavelength and simultaneous increase in f ...
of 0.016 is Abell 3627; also called the
Norma Cluster The Norma Cluster (ACO 3627 or Abell 3627) is a rich cluster of galaxies located near the center of the Great Attractor; it is about distant. Although it is both nearby and bright, it is difficult to observe because it is located in the Zone of ...
, it is one of the most massive
galaxy cluster A galaxy cluster, or a cluster of galaxies, is a structure that consists of anywhere from hundreds to thousands of galaxies that are bound together by gravity, with typical masses ranging from 1014 to 1015 solar masses. They are the second-l ...
s known to exist, at ten times the average cluster mass. Abell 3627 is thus theorized to be the
Great Attractor The Great Attractor is a gravitational anomaly in intergalactic space and the apparent central gravitational point of the Laniakea Supercluster. The observed anomalies suggest a localized concentration of mass millions of times more massive than ...
, a massive object that is pulling the
Local Group The Local Group is the galaxy group that includes the Milky Way. It has a total diameter of roughly , and a total mass of the order of . It consists of two collections of galaxies in a "dumbbell" shape: the Milky Way and its satellites form ...
, the
Virgo Supercluster The Virgo Supercluster (Virgo SC) or the Local Supercluster (LSC or LS) is a mass concentration of galaxies containing the Virgo Cluster and Local Group, which itself contains the Milky Way and Andromeda galaxies, as well as others. At least ...
, and the
Hydra–Centaurus Supercluster The Hydra-Centaurus Supercluster (SCl 128), or the Hydra and Centaurus Superclusters, is a supercluster in two parts, the closest neighbour of Virgo Supercluster. Hydra-Centaurus The cluster includes four large galaxy clusters in the Centaurus p ...
towards its location at 600–1000 kilometres per second.


Meteor shower

The relatively weak meteor shower Gamma Normids (GNO), which is typically active from March 7 to 23, peaking on March 15, has its radiant near Gamma2 Normae.


Notes


References


Sources

*


External links


The clickable Norma
{{DEFAULTSORT:Norma (constellation) Constellations Southern constellations Constellations listed by Lacaille