Musca
Encyclopedia
Musca is one of the minor southern constellation
s. The constellation was one of twelve constellations created by Petrus Plancius
from the observations of Pieter Dirkszoon Keyser
and Frederick de Houtman
and it first appeared on a 35-cm diameter celestial globe published in 1597 (or 1598) in Amsterdam by Petrus Plancius
and Jodocus Hondius
. The first depiction of this constellation in a celestial atlas was in Johann Bayer
's Uranometria
of 1603.
Nova Muscae 1991
is a binary object
consisting of a star and a black hole
. During the 1991 outburst which led to its discovery, radiation
was produced through a process of positron
annihilation
. Musca also contains the unusual planetary nebula
NGC 5189
, located about 3,000 light years from earth
. Its uniquely complex structure resembles a miniature crab nebula
. Also within the constellation is the Hourglass Nebula
(MyCn 18) at a distance of about 8,000 light years. The comparatively old globular cluster
NGC 4833
near Delta Muscae is 21,200 light years distant and somewhat obscured by dust clouds near the galactic plane
. The globular cluster NGC 4372 near Gamma Muscae is fainter and likewise partially obscured by dust, but spans more arc minutes.
to fill the previously uncharted area around the southern pole and to provide nourishment for the nearby constellation Chamaeleon
(17th-century celestial maps clearly show the chameleon's tongue trying to catch the insect). In 1752 Nicolas Louis de Lacaille
renamed it to Musca Australis, the Southern Fly – Australis, since it counterparted the now discarded constellation
of Musca Borealis
composed of a few stars in Aries
, and to avoid confusion with Apus
. Today the name is simply Musca.
Constellation
In modern astronomy, a constellation is an internationally defined area of the celestial sphere. These areas are grouped around asterisms, patterns formed by prominent stars within apparent proximity to one another on Earth's night sky....
s. The constellation was one of twelve constellations created by Petrus Plancius
Petrus Plancius
Petrus Plancius was a Dutch astronomer, cartographer and clergyman. He was born as Pieter Platevoet in Dranouter, now in Heuvelland, West Flanders. He studied theology in Germany and England...
from the observations of Pieter Dirkszoon Keyser
Pieter Dirkszoon Keyser
Pieter Dirkszoon Keyser , a.k.a. Petrus Theodori, was a Dutch navigator who mapped the southern sky....
and Frederick de Houtman
Frederick de Houtman
Frederick de Houtman , or Frederik de Houtman, was a Dutch explorer who sailed along the Western coast of Australia en route to Batavia.-Biography:...
and it first appeared on a 35-cm diameter celestial globe published in 1597 (or 1598) in Amsterdam by Petrus Plancius
Petrus Plancius
Petrus Plancius was a Dutch astronomer, cartographer and clergyman. He was born as Pieter Platevoet in Dranouter, now in Heuvelland, West Flanders. He studied theology in Germany and England...
and Jodocus Hondius
Jodocus Hondius
Jodocus Hondius , sometimes called Jodocus Hondius the Elder to distinguish him from his son Henricus Hondius II, was a Flemish artist, engraver, and cartographer...
. The first depiction of this constellation in a celestial atlas was in Johann Bayer
Johann Bayer
Johann Bayer was a German lawyer and uranographer . He was born in Rain, Bavaria, in 1572. He began his study of philosophy in Ingolstadt in 1592, and moved later to Augsburg to begin work as a lawyer. He grew interested in astronomy during his time in Augsburg...
's Uranometria
Uranometria
Uranometria is the short title of a star atlas produced by Johann Bayer.It was published in Augsburg, Germany, in 1603 by Christophorus Mangus under the full title Uranometria : omnium asterismorum continens schemata, nova methodo delineata, aereis laminis expressa. This translates to...
of 1603.
Notable objects
The soft X-ray transientSoft X-ray transient
Soft X-ray transients are composed of some type of compact object and some type of "normal", low mass star . These objects show changing levels of low-energy, or "soft", X-ray emission, probably produced somehow by variable transfer of mass from the normal star to the compact object...
Nova Muscae 1991
GRS 1124-683
The gamma-ray and X-ray source GRS 1124-683, discovered by the Granat mission and Ginga, is a system containing a black hole candidate. The system also goes by the name X-ray Nova Muscae 1991 or GU Mus...
is a binary object
Binary star
A binary star is a star system consisting of two stars orbiting around their common center of mass. The brighter star is called the primary and the other is its companion star, comes, or secondary...
consisting of a star and a black hole
Black hole
A black hole is a region of spacetime from which nothing, not even light, can escape. The theory of general relativity predicts that a sufficiently compact mass will deform spacetime to form a black hole. Around a black hole there is a mathematically defined surface called an event horizon that...
. During the 1991 outburst which led to its discovery, radiation
Radiation
In physics, radiation is a process in which energetic particles or energetic waves travel through a medium or space. There are two distinct types of radiation; ionizing and non-ionizing...
was produced through a process of positron
Positron
The positron or antielectron is the antiparticle or the antimatter counterpart of the electron. The positron has an electric charge of +1e, a spin of ½, and has the same mass as an electron...
annihilation
Annihilation
Annihilation is defined as "total destruction" or "complete obliteration" of an object; having its root in the Latin nihil . A literal translation is "to make into nothing"....
. Musca also contains the unusual planetary nebula
Planetary nebula
A planetary nebula is an emission nebula consisting of an expanding glowing shell of ionized gas ejected during the asymptotic giant branch phase of certain types of stars late in their life...
NGC 5189
NGC 5189
NGC 5189 is a planetary nebula in the constellation Musca. It was discovered by John Herschel in 1835. Seen through the telescope it seems to have an S shape, reminiscent of a barred spiral galaxy. NGC 5189 is symmetrical and is estimated to be 3,000 light years away from Earth. -External links:**...
, located about 3,000 light years from earth
Earth
Earth is the third planet from the Sun, and the densest and fifth-largest of the eight planets in the Solar System. It is also the largest of the Solar System's four terrestrial planets...
. Its uniquely complex structure resembles a miniature crab nebula
Crab Nebula
The Crab Nebula is a supernova remnant and pulsar wind nebula in the constellation of Taurus...
. Also within the constellation is the Hourglass Nebula
Hourglass Nebula
The Engraved Hourglass Nebula is a young planetary nebula situated in the southern constellation Musca about 8,000 light-years away from Earth. It was discovered by Annie Jump Cannon and Margaret W. Mayall during their work on an extended Henry Draper Catalogue...
(MyCn 18) at a distance of about 8,000 light years. The comparatively old globular cluster
Globular cluster
A globular cluster is a spherical collection of stars that orbits a galactic core as a satellite. Globular clusters are very tightly bound by gravity, which gives them their spherical shapes and relatively high stellar densities toward their centers. The name of this category of star cluster is...
NGC 4833
NGC 4833
NGC 4833 is a globular cluster discovered by Abbe Lacaille during his 1751-1752 journey to South Africa, and catalogued in 1755. It was subsequently observed and catalogued by James Dunlop and Sir John Herschel whose instruments could resolve it into individual stars.The globular cluster is...
near Delta Muscae is 21,200 light years distant and somewhat obscured by dust clouds near the galactic plane
Galactic plane
The galactic plane is the plane in which the majority of a disk-shaped galaxy's mass lies. The directions perpendicular to the galactic plane point to the galactic poles...
. The globular cluster NGC 4372 near Gamma Muscae is fainter and likewise partially obscured by dust, but spans more arc minutes.
History
Musca, under its original name Apis – the Bee, was introduced in the late 16th century by Petrus PlanciusPetrus Plancius
Petrus Plancius was a Dutch astronomer, cartographer and clergyman. He was born as Pieter Platevoet in Dranouter, now in Heuvelland, West Flanders. He studied theology in Germany and England...
to fill the previously uncharted area around the southern pole and to provide nourishment for the nearby constellation Chamaeleon
Chamaeleon
Chamaeleon is a small constellation in the southern sky. It is named after the chameleon, a form of lizard. It was first defined in the sixteenth century.-History:...
(17th-century celestial maps clearly show the chameleon's tongue trying to catch the insect). In 1752 Nicolas Louis de Lacaille
Nicolas Louis de Lacaille
Abbé Nicolas Louis de Lacaille was a French astronomer.He is noted for his catalogue of nearly 10,000 southern stars, including 42 nebulous objects. This catalogue, called Coelum Australe Stelliferum, was published posthumously in 1763. It introduced 14 new constellations which have since become...
renamed it to Musca Australis, the Southern Fly – Australis, since it counterparted the now discarded constellation
Former constellations
Former constellations are constellations that are no longer recognized by the International Astronomical Union for various reasons. Many of these constellations existed for long periods of time, even centuries in many cases, which means they still have a large historical value and can be found on...
of Musca Borealis
Musca Borealis
Musca Borealis was a constellation located between the constellations of Aries and Perseus.It was first described as such by Hevelius in his catalogue of 1690, to distinguish it from the southern fly, Musca Australis....
composed of a few stars in Aries
Aries (constellation)
Aries is one of the constellations of the zodiac, located between Pisces to the west and Taurus to the east. Its name is Latin for ram, and its symbol is , representing a ram's horns...
, and to avoid confusion with Apus
Apus
Apus is a faint constellation in the southern sky, first defined in the late 16th century. Its name means "no feet" in Greek, and it represents a bird-of-paradise . It is bordered by Triangulum Australe, Circinus, Musca, Chamaeleon, Octans, Pavo and Ara...
. Today the name is simply Musca.