Constellation | |
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Abbreviation | LMi |
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Genitive | Leonis Minoris |
Pronunciation | /ˌliːoʊˈmaɪnər/ , genitive /liːˈoʊnɪsmɪˈnɒrɪs/ |
Symbolism | the lesser Lion |
Right ascension | 9h 22.4m to 11h 06.5m |
Declination | 22.84° to 41.43° [1] |
Quadrant | NQ2 |
Area | 232 sq. deg. (64th) |
Main stars | 3 |
Bayer/Flamsteed stars | 34 |
Stars with planets | 4 |
Stars brighter than 3.00m | 0 |
Stars within 10.00 pc (32.62 ly) | 0 |
Brightest star | 46 LMi (Praecipua) (3.83 m ) |
Messier objects | 0 |
Meteor showers | Leonis Minorids |
Bordering constellations | Ursa Major Lynx Cancer (corner) Leo |
Visible at latitudes between +90° and −45°. Best visible at 21:00 (9 p.m.) during the month of April. |
Leo Minor is a small and faint constellation in the northern celestial hemisphere. Its name is Latin for "the smaller lion", in contrast to Leo, the larger lion. It lies between the larger and more recognizable Ursa Major to the north and Leo to the south. Leo Minor was not regarded as a separate constellation by classical astronomers; it was designated by Johannes Hevelius in 1687. [2]
There are 37 stars brighter than apparent magnitude 6.5 in the constellation; three are brighter than magnitude 4.5. 46 Leonis Minoris, an orange giant of magnitude 3.8, is located some 95 light-years from Earth. At magnitude 4.4, Beta Leonis Minoris is the second-brightest star and the only one in the constellation with a Bayer designation. It is a binary star, the brighter component of which is an orange giant and the fainter a yellow-white main sequence star. The third-brightest star is 21 Leonis Minoris, a rapidly rotating white main-sequence star of average magnitude 4.5. The constellation also includes two stars with planetary systems, two pairs of interacting galaxies, and the unique deep-sky object Hanny's Voorwerp.
The classical astronomers Aratus and Ptolemy had noted the region of what is now Leo Minor to be undefined and not containing any distinctive patterns; Ptolemy classified the stars in this area as amorphōtoi (not belonging to a constellation outline) within the constellation Leo. [3]
Johannes Hevelius first depicted Leo Minor in 1687 when he outlined ten new constellations in his star atlas Firmamentum Sobiescianum, [4] and included 18 of its objects in the accompanying Catalogus Stellarum Fixarum. [5] Hevelius decided upon Leo Minor or Leo Junior as a depiction that would align with its beastly neighbours the Lion and the Great Bear. [6] In 1845, English astronomer Francis Baily revised the catalogue of Hevelius's new constellations, and assigned a Greek letter known as Bayer designation to stars brighter than apparent magnitude 4.5. [7] Richard A. Proctor gave the constellation the name Leaena "the Lioness" in 1870, [3] explaining that he sought to shorten the constellation names to make them more manageable on celestial charts. [8]
German astronomer Christian Ludwig Ideler posited that the stars of Leo Minor had been termed Al Thibā' wa-Aulāduhā "Gazelle with her Young" on a 13th-century Arabic celestial globe, recovered by Cardinal Stefano Borgia and housed in the prelate's museum at Velletri. [9] [10] Arabist Friedrich Wilhelm Lach describes a different view, noting that they had been seen as Al Haud "the Pond", which the Gazelle jumps into. [3] In Chinese astronomy, the stars Beta, 30, 37 and 46 Leonis Minoris made up Neiping, a "Court of Judge or Mediator", or Shi "Court Eunuch" [11] or were combined with stars of the neighbouring Leo to make up a large celestial dragon or State Chariot. [3] [12] A line of four stars was known as Shaowei; it represented four Imperial advisors and may have been located in Leo Minor, Leo or adjacent regions. [11]
A dark area of the sky with a triangle of brighter stars just visible to the naked eye in good conditions, [13] Leo Minor has been described by Patrick Moore as having "dubious claims to a separate identity". [14] It is a small constellation bordered by Ursa Major to the north, Lynx to the west, Leo to the south, and touching the corner of Cancer to the southwest. The three-letter abbreviation for the constellation, as adopted by the International Astronomical Union in 1922, is "LMi". [15] The official constellation boundaries, as set by Belgian astronomer Eugène Delporte in 1930, are defined by a polygon of 16 sides. In the equatorial coordinate system, the right ascension coordinates of these borders lie between 9h 22.4m and 11h 06.5m, while the declination coordinates are between 22.84° and 41.43°. [1] Ranked 64th out of 88 constellations in size, Leo Minor covers an area of 232.0 square degrees, or 0.562 per cent of the sky. [16] It culminates each year at midnight on 24 February, [13] and at 9 p.m. on 24 May. [17]
There are only three stars in the constellation brighter than magnitude 4.5, [6] and 37 stars with a magnitude brighter than 6.5. [16] Leo Minor does not have a star designated Alpha because Baily erred and allocated a Greek letter to only one star, Beta. [2] It is unclear whether he intended to give 46 Leonis Minoris a Bayer designation, as he recognized Beta and 46 Leonis Minoris as of the appropriate brightness in his catalogue. He died before revising his proofs, which might explain this star's omission. [6]
At magnitude 3.8, the brightest star in Leo Minor is an orange giant of spectral class K0III named 46 Leonis Minoris or Praecipua; [18] its colour is evident when seen through binoculars. [14] Situated 95 light-years (29 parsecs ) from Earth, [2] it has around 32 times the luminosity and is 8.5 times the size of the Sun. [19] It was also catalogued and named as o Leonis Minoris by Johann Elert Bode, which has been misinterpreted as Omicron Leonis Minoris. [6] More confusion occurred with its proper name Praecipua, which appears to have been originally applied to 37 Leonis Minoris in the 1814 Palermo Catalogue of Giuseppe Piazzi, who mistakenly assessed the latter star as the brighter. This name was later connected by Allen with 46 Leonis Minoris—an error perpetuated by subsequent astronomers. [11] The original "Praecipua", 37 Leonis Minoris, has an apparent magnitude of 4.69, [20] but is a distant yellow supergiant of spectral type G2.5IIa and absolute magnitude of −1.84, [21] around 578 light-years (177 parsecs) distant. [20]
Beta Leonis Minoris is a binary star system. The primary is a giant star of spectral class G9III [22] and apparent magnitude of 4.4. It has around double the mass, 7.8 times the radius and 36 times the luminosity of the Earth's Sun. Separated by 0.1 to 0.6 second of arc from the primary, the secondary is a yellow-white main sequence star of spectral type F8. The two orbit around a common centre of gravity every 38.62 years, [23] and lie 154 light-years (47 parsecs) away from the Solar System. [24]
Around 98 light-years (30 parsecs) away and around 10 times as luminous as the Sun, 21 Leonis Minoris is a rapidly rotating white main-sequence star, spinning on its axis in less than 12 hours and very likely flattened in shape. [25] Of average apparent magnitude 4.5 and spectral type A7V, it is a Delta Scuti variable. [26] These are short period (six hours at most) pulsating stars which have been used as standard candles and as subjects to study asteroseismology. [27]
Also known as SU and SV Leonis Minoris, 10 and 11 Leonis Minoris are yellow giants of spectral type G8III, with average magnitudes 4.54 and 5.34 respectively. Both are RS Canum Venaticorum variables, [29] [30] with 10 Leonis Minoris varying by 0.012 magnitude over 40.4 days, and 11 Leonis Minoris by 0.033 magnitude over 18 days. [31] 11 Leonis Minoris has a red dwarf companion of spectral type M5V and apparent magnitude 13.0. [32] 20 Leonis Minoris is a multiple star system 49 light-years (15 parsecs) away from the Sun. The main star is another yellow star, this time a dwarf of spectral type G3Va and apparent magnitude 5.4. [33] The companion is an old, active red dwarf that has a relatively high metallicity and is of spectral type M6.5. The fact that the secondary star is brighter than expected indicates it is likely two stars very close together that are unable to be made out separately with current viewing technology. [34]
R and S Leonis Minoris are long-period Mira variables, while U Leonis Minoris is a semiregular variable; [35] all three are red giants of spectral types M6.5e-M9.0e, [36] M5e [37] and M6 respectively. [38] R varies between magnitudes 6.3 and 13.2 during a period of 372 days, S varies between magnitudes 8.6 and 13.9 during a period of 234 days, and U varies between magnitudes 10.0 and 13.3 during a period of 272 days. The lack of bright stars makes finding these objects challenging for amateur astronomers. [35] G 117-B15A, also known as RY Leonis Minoris, is a pulsating white dwarf of apparent magnitude 15.5. [39] With a period of approximately 215 seconds, and losing a second every 8.9 million years, the 400-million-year-old star has been proposed as the most stable celestial clock. [40]
SX Leonis Minoris is a dwarf nova of the SU Ursae Majoris type that was identified in 1994. [41] It consists of a white dwarf and a donor star, which orbit each other every 97 minutes. The white dwarf sucks matter from the other star onto an accretion disc and heats up to between 6000 and 10000 K. The dwarf star erupts every 34 to 64 days, reaching magnitude 13.4 in these outbursts and remaining at magnitude 16.8 when quiet. [42] Leo Minor contains another dwarf nova, RZ Leonis Minoris, which brightens to magnitude 14.2 from a baseline magnitude of around 17 but does so at shorter intervals than other dwarf novae. [43]
Two stars with planetary systems have been found. HD 87883 is an orange dwarf of magnitude 7.57 and spectral type K0V 18 parsecs distant from Earth. With a diameter three quarters that of Earth's sun, it is only 31 per cent as luminous. It is orbited by a planet around 1.78 times the mass of Jupiter every 7.9 years, and there are possibly other smaller planets. [44] HD 82886 (Illyrian) [45] is a yellow dwarf of spectral type G0 and visual magnitude 7.63. [46] A planet 1.3 times the mass of Jupiter and orbiting every 705 days was discovered in 2011. [47]
In terms of deep-sky objects, Leo Minor contains many galaxies viewable in amateur telescopes. [49] Located 3 degrees southeast of 38 Leonis Minoris, NGC 3432 is seen nearly edge on. It is of apparent magnitude 11.7 and measures 6.8 by 1.4 arcminutes. [13] Located 42 million light-years away, it is moving away from the Solar System at a rate of 616 km per second. In 2000, a star within the galaxy brightened to magnitude 17.4, and has since been determined to be a luminous blue variable and supernova impostor. [50] It has tidal filaments and intense star formation, so it was listed in Halton Arp's Atlas of Peculiar Galaxies. [51] NGC 3003, a SBbc barred spiral galaxy with an apparent magnitude of 12.3 and an angular size of 5.8 arcminutes, is seen almost edge-on. [52] NGC 3344, 25 million light-years distant, is face-on towards Earth. [53] Measuring 7.1 by 6.5 arcminutes in size, it has an apparent magnitude of 10.45. [54] NGC 3504 is a starburst barred spiral galaxy of apparent magnitude 11.67 and measuring 2.1 by 2.7 arcminutes. [55] It has hosted supernovae in 1998 [56] and 2001. [57] It and the spiral galaxy NGC 3486 are also almost face-on towards Earth; the latter is of magnitude 11.05 and measures 7.1 by 5.2 arcminutes. [58] NGC 2859 is an SB0-type lenticular galaxy. [59]
At least two pairs of interacting galaxies have been observed. Arp 107 is a pair of galaxies in the process of merging, located 450 million light-years away. [60] NGC 3395 and NGC 3396 are a spiral and irregular barred spiral galaxy, respectively, that are interacting, located 1.33 degrees southwest of 46 Leonis Minoris. [61]
The unique deep-sky object known as Hanny's Voorwerp was discovered in Leo Minor in 2007 by Dutch school teacher Hanny van Arkel while participating as a volunteer in the Galaxy Zoo project. Lying near the 650-million-light-year-distant spiral galaxy IC 2497, it is around the same size as the Milky Way. [62] It contains a 16,000-light-year-wide hole. [63] The voorwerp is thought to be the visual light echo of a quasar now gone inactive, [64] possibly as recently as 200,000 years ago. [62]
Discovered by Dick McCloskey and Annette Posen of the Harvard Meteor Program in 1959, [65] the Leonis Minorid meteor shower peaks between 18 and 29 October. The shower's parent body is the long period comet C/1739 K1 (Zanotti). [66] It is a minor shower, and can only be seen from the Northern Hemisphere. [67]
Aries is one of the constellations of the zodiac. It is located in the Northern celestial hemisphere between Pisces to the west and Taurus to the east. The name Aries is Latin for ram. Its old astronomical symbol is (♈︎). It is one of the 48 constellations described by the 2nd century astronomer Ptolemy, and remains one of the 88 modern constellations. It is a mid-sized constellation ranking 39th in overall size, with an area of 441 square degrees.
Boötes is a constellation in the northern sky, located between 0° and +60° declination, and 13 and 16 hours of right ascension on the celestial sphere. The name comes from Latin: Boōtēs, which comes from Greek: Βοώτης, translit. Boṓtēs 'herdsman' or 'plowman'.
Canis Major is a constellation in the southern celestial hemisphere. In the second century, it was included in Ptolemy's 48 constellations, and is counted among the 88 modern constellations. Its name is Latin for "greater dog" in contrast to Canis Minor, the "lesser dog"; both figures are commonly represented as following the constellation of Orion the hunter through the sky. The Milky Way passes through Canis Major and several open clusters lie within its borders, most notably M41.
Canis Minor is a small constellation in the northern celestial hemisphere. In the second century, it was included as an asterism, or pattern, of two stars in Ptolemy's 48 constellations, and it is counted among the 88 modern constellations. Its name is Latin for "lesser dog", in contrast to Canis Major, the "greater dog"; both figures are commonly represented as following the constellation of Orion the hunter.
Corona Australis is a constellation in the Southern Celestial Hemisphere. Its Latin name means "southern crown", and it is the southern counterpart of Corona Borealis, the northern crown. It is one of the 48 constellations listed by the 2nd-century astronomer Ptolemy, and it remains one of the 88 modern constellations. The Ancient Greeks saw Corona Australis as a wreath rather than a crown and associated it with Sagittarius or Centaurus. Other cultures have likened the pattern to a turtle, ostrich nest, a tent, or even a hut belonging to a rock hyrax.
Grus is a constellation in the southern sky. Its name is Latin for the crane, a type of bird. It is one of twelve constellations conceived by Petrus Plancius from the observations of Pieter Dirkszoon Keyser and Frederick de Houtman. Grus first appeared on a 35-centimetre-diameter (14-inch) celestial globe published in 1598 in Amsterdam by Plancius and Jodocus Hondius and was depicted in Johann Bayer's star atlas Uranometria of 1603. French explorer and astronomer Nicolas-Louis de Lacaille gave Bayer designations to its stars in 1756, some of which had been previously considered part of the neighbouring constellation Piscis Austrinus. The constellations Grus, Pavo, Phoenix and Tucana are collectively known as the "Southern Birds".
Hydrus is a small constellation in the deep southern sky. It 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 (14 in) diameter celestial globe published in late 1597 in Amsterdam by Plancius and Jodocus Hondius. The first depiction of this constellation in a celestial atlas was in Johann Bayer's Uranometria of 1603. The French explorer and astronomer Nicolas Louis de Lacaille charted the brighter stars and gave their Bayer designations in 1756. Its name means "male water snake", as opposed to Hydra, a much larger constellation that represents a female water snake. It remains below the horizon for most Northern Hemisphere observers.
Triangulum is a small constellation in the northern sky. Its name is Latin for "triangle", derived from its three brightest stars, which form a long and narrow triangle. Known to the ancient Babylonians and Greeks, Triangulum was one of the 48 constellations listed by the 2nd century astronomer Ptolemy. The celestial cartographers Johann Bayer and John Flamsteed catalogued the constellation's stars, giving six of them Bayer designations.
Tucana is a constellation of stars in the southern sky, named after the toucan, a South American bird. It is one of twelve constellations conceived in the late sixteenth century by Petrus Plancius from the observations of Pieter Dirkszoon Keyser and Frederick de Houtman. Tucana first appeared on a 35-centimetre-diameter (14 in) celestial globe published in 1598 in Amsterdam by Plancius and Jodocus Hondius and was depicted in Johann Bayer's star atlas Uranometria of 1603. French explorer and astronomer Nicolas Louis de Lacaille gave its stars Bayer designations in 1756. The constellations Tucana, Grus, Phoenix and Pavo are collectively known as the "Southern Birds".
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 pattern of its three brightest stars. It was first depicted on a celestial globe as Triangulus Antarcticus by Petrus Plancius in 1589, and later with more accuracy and its current name by Johann Bayer in his 1603 Uranometria. The French explorer and astronomer Nicolas Louis de Lacaille charted and gave the brighter stars their Bayer designations in 1756.
Telescopium is a minor constellation in the southern celestial hemisphere, one of twelve named in the 18th century by French astronomer Nicolas-Louis de Lacaille and one of several depicting scientific instruments. Its name is a Latinized form of the Greek word for telescope. Telescopium was later much reduced in size by Francis Baily and Benjamin Gould.
Ursa Minor, also known as the Little Bear, is a constellation located in the far northern sky. As with the Great Bear, the tail of the Little Bear may also be seen as the handle of a ladle, hence the North American name, Little Dipper: seven stars with four in its bowl like its partner the Big Dipper. Ursa Minor was one of the 48 constellations listed by the 2nd-century astronomer Ptolemy, and remains one of the 88 modern constellations. Ursa Minor has traditionally been important for navigation, particularly by mariners, because of Polaris being the north pole star.
Phoenix is a minor constellation in the southern sky. Named after the mythical phoenix, it was first depicted on a celestial atlas by Johann Bayer in his 1603 Uranometria. The French explorer and astronomer Nicolas Louis de Lacaille charted the brighter stars and gave their Bayer designations in 1756. The constellation stretches from roughly −39° to −57° declination, and from 23.5h to 2.5h of right ascension. The constellations Phoenix, Grus, Pavo and Tucana, are known as the Southern Birds.
Andromeda is one of the 48 constellations listed by the 2nd-century Greco-Roman astronomer Ptolemy, and one of the 88 modern constellations. Located in the northern celestial hemisphere, it is named for Andromeda, daughter of Cassiopeia, in the Greek myth, who was chained to a rock to be eaten by the sea monster Cetus. Andromeda is most prominent during autumn evenings in the Northern Hemisphere, along with several other constellations named for characters in the Perseus myth. Because of its northern declination, Andromeda is visible only north of 40° south latitude; for observers farther south, it lies below the horizon. It is one of the largest constellations, with an area of 722 square degrees. This is over 1,400 times the size of the full moon, 55% of the size of the largest constellation, Hydra, and over 10 times the size of the smallest constellation, Crux.
Perseus is a constellation in the northern sky, named after the Greek mythological hero Perseus. It is one of the 48 ancient constellations listed by the 2nd-century astronomer Ptolemy, and among the 88 modern constellations defined by the International Astronomical Union (IAU). It is located near several other constellations named after ancient Greek legends surrounding Perseus, including Andromeda to the west and Cassiopeia to the north. Perseus is also bordered by Aries and Taurus to the south, Auriga to the east, Camelopardalis to the north, and Triangulum to the west. Some star atlases during the early 19th century also depicted Perseus holding the disembodied head of Medusa, whose asterism was named together as Perseus et Caput Medusae; however, this never came into popular usage.
Auriga is a constellation in the northern celestial hemisphere. It is one of the 88 modern constellations; it was among the 48 constellations listed by the 2nd-century astronomer Ptolemy. Its name is Latin for '(the) charioteer', associating it with various mythological beings, including Erichthonius and Myrtilus. Auriga is most prominent during winter evenings in the northern Hemisphere, as are five other constellations that have stars in the Winter Hexagon asterism. Because of its northern declination, Auriga is only visible in its entirety as far south as -34°; for observers farther south it lies partially or fully below the horizon. A large constellation, with an area of 657 square degrees, it is half the size of the largest, Hydra.
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, referring to the drafting tool used for drawing circles. Its brightest star is Alpha Circini, with an apparent magnitude of 3.19. Slightly variable, it is the brightest rapidly oscillating Ap star in the night sky. AX Circini is a Cepheid variable visible with the unaided eye, and BX Circini is a faint star thought to have been formed from the merger of two white dwarfs. Two sun-like stars have planetary systems: HD 134060 has two small planets, and HD 129445 has a Jupiter-like planet. Supernova SN 185 appeared in Circinus in 185 AD and was recorded by Chinese observers. Two novae have been observed more recently, in the 20th century.
Pictor is a constellation in the Southern Celestial Hemisphere, located between the star Canopus and the Large Magellanic Cloud. Its name is Latin for painter, and is an abbreviation of the older name Equuleus Pictoris. Normally represented as an easel, Pictor was named by Abbé Nicolas-Louis de Lacaille in the 18th century. The constellation's brightest star is Alpha Pictoris, a white main-sequence star around 97 light-years away from Earth. Pictor also hosts RR Pictoris, a cataclysmic variable star system that flared up as a nova, reaching apparent (visual) magnitude 1.2 in 1925 before fading into obscurity.
Musca is a small constellation in the deep southern sky. It was one of 12 constellations created by Petrus Plancius from the observations of Pieter Dirkszoon Keyser and Frederick de Houtman, and it first appeared on a celestial globe 35 cm (14 in) in diameter published in 1597 in Amsterdam by Plancius and Jodocus Hondius. The first depiction of this constellation in a celestial atlas was in Johann Bayer's Uranometria of 1603. It was also known as Apis for 200 years. Musca remains below the horizon for most Northern Hemisphere observers.
Pavo is a constellation in the southern sky whose name is Latin for 'peacock'. Pavo first appeared on a 35-cm (14 in) diameter celestial globe published in 1598 in Amsterdam by Petrus Plancius and Jodocus Hondius and was depicted in Johann Bayer's star atlas Uranometria of 1603, and was likely conceived by Plancius from the observations of Pieter Dirkszoon Keyser and Frederick de Houtman. French explorer and astronomer Nicolas-Louis de Lacaille gave its stars Bayer designations in 1756. The constellations Pavo, Grus, Phoenix and Tucana are collectively known as the "Southern Birds".
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