Ursa Major Moving Group
Encyclopedia
The Ursa Major Moving Group, also known as Collinder 285 or Ursa Major association, is a nearby stellar moving group, a set of stars with common velocities in space and thought to have a common origin. Its core is located roughly 80 light years away. It is rich in bright stars including most of the stars of the Big Dipper
.
s, and, based on stellar theory, appear to be roughly the same age. This evidence suggests to astronomers that the stars in the group share a common origin.
Based on the numbers of its constituent stars, the Ursa Major Moving Group is believed to have once been an open cluster
, having formed from a protostellar nebula
approximately 500 million years ago. Since then, the sparse group has scattered over a region about 30 by 18 light-years, whose center is currently some 80 light-years away, making it the closest cluster-like object
to Earth
.
The Ursa Major Moving Group was discovered in 1869 by Richard A. Proctor, who noticed that, except for Dubhe and Alkaid, the stars of the Big Dipper
asterism
all have proper motion
s heading towards a common point in Sagittarius
. Thus, the Big Dipper, unlike most constellations or asterisms, is largely composed of related stars.
Some of the brighter stream members include Alpha Coronae Borealis (α CrB or Alphecca or Gemma), Beta Aurigae
(β Aur), Delta Aquarii
(δ Aqr), Gamma Leporis
(γ Lep) and Beta Serpentis
(β Ser). More bright and moderately bright stars which are currently believed to be members of the group are listed in two sections below: Core stars and Stream stars.
(or distance) to the stars and radial velocities
. The Hipparcos
satellite has recently greatly improved both the proper motion and parallax estimates of nearby bright stars, refining the study of this and other moving groups http://adsabs.harvard.edu/cgi-bin/nph-bib_query?bibcode=2003AJ....125.1980K&db_key=AST&data_type=HTML&format=&high=41b4ade78800742.
Based on their distances (measured with Hipparcos) and apparent magnitude
, the absolute magnitude
can be used to estimate the age of the stars. The stars in the moving group appear to have a common age of about 500 million years.
constellation
and the other is in the neighboring constellation of Canes Venatici
.
The following are members of the moving group closest to its center. These stars are all in Ursa Major
except where indicated.
to Triangulum Australe
).
was long believed to be a member of the group, but may not be, according to research in 2003 by Jeremy King et al. at Clemson University
. This research seems to indicate that it is too young to be a member.
Our Solar System
is in the outskirts of this stream, but is not a member, being about 10 times older. Our Sun
merely drifted in along its 250-million-year galactic orbit, and 40 million years ago was nowhere near the Ursa Major group.
Big Dipper
The Plough, also known as the Big Dipper or the Saptarishi , is an asterism of seven stars that has been recognized as a distinct grouping in many cultures from time immemorial...
.
Discovery and constituents
All stars in the Ursa Major Moving Group are moving in roughly the same direction at roughly the same speed, contain roughly the same mix of metalMetallicity
In astronomy and physical cosmology, the metallicity of an object is the proportion of its matter made up of chemical elements other than hydrogen and helium...
s, and, based on stellar theory, appear to be roughly the same age. This evidence suggests to astronomers that the stars in the group share a common origin.
Based on the numbers of its constituent stars, the Ursa Major Moving Group is believed to have once been an open cluster
Open cluster
An open cluster is a group 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 many more are thought to exist...
, having formed from a protostellar nebula
Nebula
A nebula is an interstellar cloud of dust, hydrogen gas, helium gas and other ionized gases...
approximately 500 million years ago. Since then, the sparse group has scattered over a region about 30 by 18 light-years, whose center is currently some 80 light-years away, making it the closest cluster-like object
Star cluster
Star clusters or star clouds are groups of stars. Two types of star clusters can be distinguished: globular clusters are tight groups of hundreds of thousands of very old stars which are gravitationally bound, while open clusters, more loosely clustered groups of stars, generally contain less than...
to 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...
.
The Ursa Major Moving Group was discovered in 1869 by Richard A. Proctor, who noticed that, except for Dubhe and Alkaid, the stars of the Big Dipper
Big Dipper
The Plough, also known as the Big Dipper or the Saptarishi , is an asterism of seven stars that has been recognized as a distinct grouping in many cultures from time immemorial...
asterism
Asterism (astronomy)
In astronomy, an asterism is a pattern of stars recognized on Earth's night sky. It may form part of an official constellation, or be composed of stars from more than one. Like constellations, asterisms are in most cases composed of stars which, while they are visible in the same general direction,...
all have proper motion
Proper motion
The proper motion of a star is its angular change in position over time as seen from the center of mass of the solar system. It is measured in seconds of arc per year, arcsec/yr, where 3600 arcseconds equal one degree. This contrasts with radial velocity, which is the time rate of change in...
s heading towards a common point in Sagittarius
Sagittarius (constellation)
Sagittarius is a constellation of the zodiac, the one containing the galactic center. Its name is Latin for the archer, and its symbol is , a stylized arrow. Sagittarius is commonly represented as a centaur drawing a bow...
. Thus, the Big Dipper, unlike most constellations or asterisms, is largely composed of related stars.
Some of the brighter stream members include Alpha Coronae Borealis (α CrB or Alphecca or Gemma), Beta Aurigae
Beta Aurigae
Beta Aurigae , traditionally named Menkalinan, is a white subgiant ternary star system approximately 85 light-years away in the constellation Auriga.- Nomenclature :...
(β Aur), Delta Aquarii
Delta Aquarii
Delta Aquarii is the third-brightest star in the constellation Aquarius. It has the traditional name Skat, which has also been used for Beta Pegasi....
(δ Aqr), Gamma Leporis
Gamma Leporis
Gamma Leporis is a star that is located at a distance of about 29 light-years from Earth. Gamma Leporis lies in the south central part of the constellation Lepus, southeast of Beta Leporis and southwest of Delta Leporis. It has a common proper motion companion, AK Leporis, which is a variable star...
(γ Lep) and Beta Serpentis
Beta Serpentis
Beta Serpentis is a star system in the constellation Serpens, in its head . It was a member of indigenous Arabic asterism al-Nasaq al-Sha'āmī, "the Northern Line" of al-Nasaqān "the Two Lines", along with β Her , γ Her and γ Ser .According to the catalogue of stars in the Technical Memorandum...
(β Ser). More bright and moderately bright stars which are currently believed to be members of the group are listed in two sections below: Core stars and Stream stars.
Group members
Current criteria for membership in the moving group is based on the stars' motion in space. This motion can be determined from the proper motions and parallaxParallax
Parallax is a displacement or difference in the apparent position of an object viewed along two different lines of sight, and is measured by the angle or semi-angle of inclination between those two lines. The term is derived from the Greek παράλλαξις , meaning "alteration"...
(or distance) to the stars and radial velocities
Radial velocity
Radial velocity is the velocity of an object in the direction of the line of sight . In astronomy, radial velocity most commonly refers to the spectroscopic radial velocity...
. The Hipparcos
Hipparcos
Hipparcos was a scientific mission of the European Space Agency , launched in 1989 and operated between 1989 and 1993. It was the first space experiment devoted to precision astrometry, the accurate measurement of the positions of celestial objects on the sky...
satellite has recently greatly improved both the proper motion and parallax estimates of nearby bright stars, refining the study of this and other moving groups http://adsabs.harvard.edu/cgi-bin/nph-bib_query?bibcode=2003AJ....125.1980K&db_key=AST&data_type=HTML&format=&high=41b4ade78800742.
Based on their distances (measured with Hipparcos) and apparent magnitude
Apparent magnitude
The apparent magnitude of a celestial body is a measure of its brightness as seen by an observer on Earth, adjusted to the value it would have in the absence of the atmosphere...
, the absolute magnitude
Absolute magnitude
Absolute magnitude is the measure of a celestial object's intrinsic brightness. it is also the apparent magnitude a star would have if it were 32.6 light years away from Earth...
can be used to estimate the age of the stars. The stars in the moving group appear to have a common age of about 500 million years.
Core stars
The core of the moving group consists of 14 stars, of which 13 are in the Ursa MajorUrsa Major
Ursa Major , also known as the Great Bear, is a constellation visible throughout the year in most of the northern hemisphere. It can best be seen in April...
constellation
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....
and the other is in the neighboring constellation of Canes Venatici
Canes Venatici
Canes Venatici is one of the 88 official modern constellations. It is a small northern constellation that was created by Johannes Hevelius in the 17th century. Its name is Latin for "hunting dogs", and the constellation is often depicted in illustrations as representing the dogs of Boötes the...
.
The following are members of the moving group closest to its center. These stars are all in Ursa Major
Ursa Major
Ursa Major , also known as the Great Bear, is a constellation visible throughout the year in most of the northern hemisphere. It can best be seen in April...
except where indicated.
| Name | Constellation 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.... |
B Bayer designation A Bayer designation is a stellar designation in which a specific star is identified by a Greek letter, followed by the genitive form of its parent constellation's Latin name... |
F Flamsteed designation Flamsteed designations for stars are similar to Bayer designations, except that they use numbers instead of Greek letters. Each star is assigned a number and the Latin genitive of the constellation it lies in... |
HD Henry Draper Catalogue The Henry Draper Catalogue is an astronomical star catalogue published between 1918 and 1924, giving spectroscopic classifications for 225,300 stars; it was later expanded by the Henry Draper Extension , published between 1925 and 1936, which gave classifications for 46,850 more stars, and by the... |
HIP | vis. mag. Apparent magnitude The apparent magnitude of a celestial body is a measure of its brightness as seen by an observer on Earth, adjusted to the value it would have in the absence of the atmosphere... |
Dist. (ly) | Sp. class Stellar classification In astronomy, stellar classification is a classification of stars based on their spectral characteristics. The spectral class of a star is a designated class of a star describing the ionization of its chromosphere, what atomic excitations are most prominent in the light, giving an objective measure... |
Notes |
|---|---|---|---|---|---|---|---|---|---|
| ε UMa Epsilon Ursae Majoris Epsilon Ursae Majoris is the brightest star in the constellation Ursa Major , and at magnitude 1.76 is the thirty-first brightest star in the sky... |
Ursa Major Ursa Major Ursa Major , also known as the Great Bear, is a constellation visible throughout the year in most of the northern hemisphere. It can best be seen in April... |
ε | 77 | 112185 | 62956 | 1.76 | 81 | A0p | Alioth |
| ζ UMa Mizar (star) The Mizar–Alcor stellar sextuple system consists of the quadruple system Mizar and the binary system Alcor.- Description :Mizar is a quadruple system of two binary stars in the constellation Ursa Major and is the second star from the end of the Big Dipper's handle. Its apparent magnitude is 2.23... A |
Ursa Major Ursa Major Ursa Major , also known as the Great Bear, is a constellation visible throughout the year in most of the northern hemisphere. It can best be seen in April... |
ζ | 79 | 116656 | 65378 | 2.23 | 78 | A2V | Mizar, Mizat, Mirza, Mitsar, Vasistha |
| β UMa Beta Ursae Majoris Beta Ursae Majoris is a star in the constellation of Ursa Major. It has the traditional name Merak.It is more familiar to northern hemisphere observers as one of the "pointer stars" in the Big Dipper, and a straight line connecting it with nearby Alpha Ursae Majoris extends to Polaris, the north... |
Ursa Major Ursa Major Ursa Major , also known as the Great Bear, is a constellation visible throughout the year in most of the northern hemisphere. It can best be seen in April... |
β | 48 | 95418 | 53910 | 2.34 | 79 | A1V | Merak, Mirak |
| γ UMa Gamma Ursae Majoris Gamma Ursae Majoris is a star in the constellation Ursa Major. It has the traditional name Phad, or Phecda, from the Arabic phrase فخذ الدب "fakhð ad-dubb" .... |
Ursa Major Ursa Major Ursa Major , also known as the Great Bear, is a constellation visible throughout the year in most of the northern hemisphere. It can best be seen in April... |
γ | 64 | 103287 | 58001 | 2.41 | 84 | A0V SB | Phad, Phecda, Phegda, Phekha, Phacd |
| δ UMa Delta Ursae Majoris Delta Ursae Majoris is a star in the constellation Ursa Major. It has the traditional names Megrez , from the al-maghriz "the base [of the bear's tail]", and Kaffa.... |
Ursa Major Ursa Major Ursa Major , also known as the Great Bear, is a constellation visible throughout the year in most of the northern hemisphere. It can best be seen in April... |
δ | 69 | 106591 | 59774 | 3.32 | 81 | A3V | Megrez, Kaffa |
| ζ UMa Mizar (star) The Mizar–Alcor stellar sextuple system consists of the quadruple system Mizar and the binary system Alcor.- Description :Mizar is a quadruple system of two binary stars in the constellation Ursa Major and is the second star from the end of the Big Dipper's handle. Its apparent magnitude is 2.23... B |
Ursa Major Ursa Major Ursa Major , also known as the Great Bear, is a constellation visible throughout the year in most of the northern hemisphere. It can best be seen in April... |
ζ | 79 | 116657 | 3.95 | Mizar, Mizat, Mirza, Mitsar, Vasistha | |||
| 80 UMa Mizar (star) The Mizar–Alcor stellar sextuple system consists of the quadruple system Mizar and the binary system Alcor.- Description :Mizar is a quadruple system of two binary stars in the constellation Ursa Major and is the second star from the end of the Big Dipper's handle. Its apparent magnitude is 2.23... |
Ursa Major Ursa Major Ursa Major , also known as the Great Bear, is a constellation visible throughout the year in most of the northern hemisphere. It can best be seen in April... |
g | 80 | 116842 | 65477 | 3.99 | 81 | A5V SB | Alcor, Saidak, Suha, Arundhati |
| 78 UMa | Ursa Major Ursa Major Ursa Major , also known as the Great Bear, is a constellation visible throughout the year in most of the northern hemisphere. It can best be seen in April... |
78 | 113139 | 63503 | 4.93 | 81 | F2V | ||
| 37 UMa | Ursa Major Ursa Major Ursa Major , also known as the Great Bear, is a constellation visible throughout the year in most of the northern hemisphere. It can best be seen in April... |
37 | 91480 | 51814 | 5.16 | 86 | F1V | ||
| HD 115043 | Ursa Major Ursa Major Ursa Major , also known as the Great Bear, is a constellation visible throughout the year in most of the northern hemisphere. It can best be seen in April... |
115043 | 64532 | 6.82 | 84 | G1V | Gliese 503.2 | ||
| HD 109011 | Ursa Major Ursa Major Ursa Major , also known as the Great Bear, is a constellation visible throughout the year in most of the northern hemisphere. It can best be seen in April... |
109011 | 61100 | 8.10 | 77 | K2V | NO UMa | ||
| HD 110463 | Ursa Major Ursa Major Ursa Major , also known as the Great Bear, is a constellation visible throughout the year in most of the northern hemisphere. It can best be seen in April... |
110463 | 61946 | 8.28 | 76 | K3V | NP UMa | ||
| HD 109647 | Canes Venatici Canes Venatici Canes Venatici is one of the 88 official modern constellations. It is a small northern constellation that was created by Johannes Hevelius in the 17th century. Its name is Latin for "hunting dogs", and the constellation is often depicted in illustrations as representing the dogs of Boötes the... |
109647 | 61481 | 8.53 | 86 | K0 | DO CVn |
Stream stars
There is also a "stream" of stars which are likely members of the Ursa Major Moving Group, scattered more widely across the sky (from CepheusCepheus (constellation)
Cepheus is a constellation in the northern sky. It is named after Cepheus, King of Aethiopia in Greek mythology. It was one of the 48 constellations listed by the 2nd century astronomer Ptolemy, and remains one of the 88 modern constellations.-Stars:...
to Triangulum Australe
Triangulum Australe
Triangulum Australe is a small constellation in the southern sky, created in the sixteenth century. Its name is Latin for 'the southern triangle', which distinguishes it from Triangulum in the northern sky...
).
| Name | Constellation 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.... |
B Bayer designation A Bayer designation is a stellar designation in which a specific star is identified by a Greek letter, followed by the genitive form of its parent constellation's Latin name... |
F Flamsteed designation Flamsteed designations for stars are similar to Bayer designations, except that they use numbers instead of Greek letters. Each star is assigned a number and the Latin genitive of the constellation it lies in... |
HD Henry Draper Catalogue The Henry Draper Catalogue is an astronomical star catalogue published between 1918 and 1924, giving spectroscopic classifications for 225,300 stars; it was later expanded by the Henry Draper Extension , published between 1925 and 1936, which gave classifications for 46,850 more stars, and by the... |
HIP | vis. mag. Apparent magnitude The apparent magnitude of a celestial body is a measure of its brightness as seen by an observer on Earth, adjusted to the value it would have in the absence of the atmosphere... |
Dist. (ly) | Sp. class Stellar classification In astronomy, stellar classification is a classification of stars based on their spectral characteristics. The spectral class of a star is a designated class of a star describing the ionization of its chromosphere, what atomic excitations are most prominent in the light, giving an objective measure... |
Notes |
|---|---|---|---|---|---|---|---|---|---|
| β Aur Beta Aurigae Beta Aurigae , traditionally named Menkalinan, is a white subgiant ternary star system approximately 85 light-years away in the constellation Auriga.- Nomenclature :... |
Auriga Auriga Auriga can refer to:*Auriga , a constellation of stars*Auriga , a Roman slave chauffeur*HMS Auriga , a British submarine launched in 1945*"Auriga of Delphi", name of the statue "Charioteer of Delphi"... |
β | 34 | 40183 | 28360 | 1.90 | 82 | A2V | Menkalinan, Menkalina |
| α CrB | Corona Borealis Corona Borealis Corona Borealis is a small constellation in the northern sky. Its name is Latin for "northern crown", a name inspired by its shape; its main stars form a semicircular arc. It was one of the 48 constellations listed by the 2nd century astronomer Ptolemy and remains one of the 88 modern... |
α | 5 | 139006 | 76267 | 2.22 | 75 | A0V | Alphecca, Alphacca, Alphekka, Gemma, Gnosia, Gnosia Stella Coronae, Asteroth, Ashtaroth |
| δ Aqr Delta Aquarii Delta Aquarii is the third-brightest star in the constellation Aquarius. It has the traditional name Skat, which has also been used for Beta Pegasi.... |
Aquarius Aquarius (constellation) Aquarius is a constellation of the zodiac, situated between Capricornus and Pisces. Its name is Latin for "water-bearer" or "cup-bearer", and its symbol is , a representation of water.... |
δ | 76 | 216627 | 113136 | 3.27 | 159 | A3V | Skat, Scheat, Seat, Sheat |
| ζ Leo Zeta Leonis Zeta Leonis is a fourth-magnitude star in the constellation Leo. It has the traditional name Adhafera , from the Arabic الضفيرة al-ðafīrah "the braid/curl", a reference clearly to its position in the lion's mane.- Properties :Adhafera is a rare F Class giant star with stellar classification F0III... |
Leo Leo (constellation) Leo is one of the constellations of the zodiac. Its name is Latin for lion. Its symbol is . Leo lies between dim Cancer to the west and Virgo to the east.-Stars:... |
ζ | 36 | 89025 | 50335 | 3.43 | 260 | F0III | Adhafera, Aldhafera, Aldhafara |
| γ Lep A Gamma Leporis Gamma Leporis is a star that is located at a distance of about 29 light-years from Earth. Gamma Leporis lies in the south central part of the constellation Lepus, southeast of Beta Leporis and southwest of Delta Leporis. It has a common proper motion companion, AK Leporis, which is a variable star... |
Lepus Lepus Lepus is the genus of hares.Lepus may also be:* Lepus , a group of stars* Arieşeni, a commune in Romania* Lepus-the story of a hare, a book by D.Brian Plummer... |
γ | 13 | 38393 | 27072 | 3.59 | 29 | F7V | |
| β Ser Beta Serpentis Beta Serpentis is a star system in the constellation Serpens, in its head . It was a member of indigenous Arabic asterism al-Nasaq al-Sha'āmī, "the Northern Line" of al-Nasaqān "the Two Lines", along with β Her , γ Her and γ Ser .According to the catalogue of stars in the Technical Memorandum... |
Serpens Serpens Serpens is a constellation of the northern hemisphere. It was one of the 48 constellations listed by the 2nd century astronomer Ptolemy and it remains one of the 88 modern constellations defined by the International Astronomical Union.... |
β | 28 | 141003 | 77233 | 3.65 | 153 | A3V | Chow |
| ζ Boo Zeta Boötis Zeta Boötis is a bright speckle binary in the constellation of Boötes. It also has the Flamsteed designation 30 Boötis. It is approximately 181 light years from Earth and has a combined apparent magnitude of +3.78.... A |
Boötes Boötes 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 the Greek Βοώτης, Boōtēs, meaning herdsman or plowman... |
ζ | 30 | 129246 | 71795 | 3.78 | 180 | A3IVn | |
| χ1 Ori | Orion Orion (constellation) Orion, often referred to as The Hunter, is a prominent constellation located on the celestial equator and visible throughout the world. It is one of the most conspicuous, and most recognizable constellations in the night sky... |
χ1 | 54 | 39587 | 27913 | 4.39 | 28 | G0V | |
| ζ Boo Zeta Boötis Zeta Boötis is a bright speckle binary in the constellation of Boötes. It also has the Flamsteed designation 30 Boötis. It is approximately 181 light years from Earth and has a combined apparent magnitude of +3.78.... B |
Boötes Boötes 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 the Greek Βοώτης, Boōtēs, meaning herdsman or plowman... |
ζ | 30 | 129247 | 4.43 | 180 | A2III | ||
| 21 LMi | Leo Minor Leo Minor Leo Minor is a small and faint constellation. Its name means "the smaller lion", in contrast to Leo, the larger lion. Its brightest stars form a rough triangle, and it lies between the larger and more recognizable Ursa Major and Leo... |
21 | 87696 | 49593 | 4.49 | 91 | A7V | ||
| χ Cet A | Cetus Cetus Cetus is a constellation. Its name refers to Cetus, a sea monster in Greek mythology, although it is often called 'the whale' today. Cetus is located in the region of the sky that contains other water-related constellations such as Aquarius, Pisces, and Eridanus.-Ecliptic:Although Cetus is not... |
χ | 53 | 11171 | 8497 | 4.66 | 77 | F3III | |
| γ Mic Gamma Microscopii Gamma Microscopii is the brightest star in the constellation of Microscopium. It is a G-type giant star with an apparent visual magnitude of approximately 4.677, around 220 light-years from the Sun... |
Microscopium Microscopium Microscopium is a small constellation in the southern sky, created in the 18th century by Nicolas Louis de Lacaille. Its name is Latin for microscope. Its stars are very faint and hardly visible from most of the non-tropical northern hemisphere.-References:... |
γ | 39 | 199951 | 103738 | 4.67 | 223 | G8III | |
| ζ Crt | Crateris | ζ | 27 | 102070 | 57283 | 4.71 | 350 | G8III | |
| ζ TrA Zeta Trianguli Australis Zeta Trianguli Australis is a spectroscopic binary in the constellation Triangulum Australe. It is approximately 39.5 light years from Earth.... |
Triangulum Australe Triangulum Australe Triangulum Australe is a small constellation in the southern sky, created in the sixteenth century. Its name is Latin for 'the southern triangle', which distinguishes it from Triangulum in the northern sky... |
ζ | 31 | 147584 | 80686 | 4.90 | 39 | F9V | |
| 16 Lyr 16 Lyrae 16 Lyrae is a 5th magnitude star in the constellation Lyra, approximately 128 light years away from Earth. It is a white star of the spectral type A7V, meaning it has a surface temperature of 7,500 to 11,000 kelvins. It is a dwarf star, like our Sun, but much hotter and brighter.... |
Lyra Lyra Lyra is a small constellation. It is one of the 48 constellations listed by the 2nd century astronomer Ptolemy, and remains one of the 88 modern constellations recognized by the International Astronomical Union. Its principal star, Vega — a corner of the Summer Triangle — is one of the brightest... |
16 | 177196 | 93408 | 5.00 | 128 | A7V | ||
| 66 Tau | Taurus Taurus (constellation) Taurus is one of the constellations of the zodiac. Its name is a Latin word meaning 'bull', and its astrological symbol is a stylized bull's head:... |
r | 66 | 27820 | 20522 | 5.10 | 396 | A3V | |
| 59 Dra | Draco Draco (constellation) Draco is a constellation in the far northern sky. Its name is Latin for dragon. Draco is circumpolar for many observers in the northern hemisphere... |
59 | 180777 | 94083 | 5.11 | 89 | A9V | ||
| 89 Psc | Pisces Pisces (constellation) Pisces is a constellation of the zodiac. Its name is the Latin plural for fish, and its symbol is . It lies between Aquarius to the west and Aries to the east... |
f | 89 | 7804 | 6061 | 5.13 | 220 | A3V | |
| HD 75605 | Pyxis Pyxis Pyxis is a small and faint constellation in the southern sky. Its name is Latin for a mariner's compass... |
75605 | 43352 | 5.19 | 229 | G8III | |||
| 18 Boo 18 Boötis 18 Boötis is a star in the constellation Boötes about 85 light years away from Earth. Its apparent magnitude is 5.40 and its absolute magnitude is 3.3.... |
Boötes Boötes 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 the Greek Βοώτης, Boōtēs, meaning herdsman or plowman... |
18 | 125451 | 69989 | 5.41 | 85 | F5IV | ||
| HD 109799 | Hydra Hydra (constellation) Hydra is the largest of the 88 modern constellations, measuring 1303 square degrees. It has a long history, having been included among the 48 constellations listed by the 2nd century astronomer Ptolemy. It is commonly represented as a water snake... |
109799 | 61621 | 5.41 | 113 | F0V | |||
| π1 UMa Pi Ursae Majoris The Bayer designation Pi Ursae Majoris is shared by two stars in the constellation Ursa Major:* Pi¹ Ursae Majoris * Pi² Ursae Majoris They are separated by 0.70° in the sky... |
Ursa Major Ursa Major Ursa Major , also known as the Great Bear, is a constellation visible throughout the year in most of the northern hemisphere. It can best be seen in April... |
π1 | 3 | 72905 | 42438 | 5.63 | 47 | G1.5Vb | Muscida |
| HD 220096 | Sculptor | 220096 | 115312 | 5.65 | 329 | G5IV | |||
| 29 Com | Coma Berenices Coma Berenices Coma Berenices is a traditional asterism that has since been defined as one of the 88 modern constellations. It is located near Leo, to which it formerly belonged, and accommodates the North Galactic Pole... |
29 | 111397 | 62541 | 5.71 | 402 | A1V | ||
| HD 18778 | Cepheus Cepheus (constellation) Cepheus is a constellation in the northern sky. It is named after Cepheus, King of Aethiopia in Greek mythology. It was one of the 48 constellations listed by the 2nd century astronomer Ptolemy, and remains one of the 88 modern constellations.-Stars:... |
18778 | 14844 | 5.92 | 202 | A7III-IV | |||
| HD 165185 | Sagittarius Sagittarius (constellation) Sagittarius is a constellation of the zodiac, the one containing the galactic center. Its name is Latin for the archer, and its symbol is , a stylized arrow. Sagittarius is commonly represented as a centaur drawing a bow... |
165185 | 88694 | 5.94 | 57 | G3V | Gliese 702.1 | ||
| 6 Sex | Sextans Sextans Sextans is a minor equatorial constellation which was introduced in 1687 by Johannes Hevelius. Its name is Latin for the astronomical sextant, an instrument that Hevelius made frequent use of in his observations.-Notable features:... |
6 | 85364 | 48341 | 6.01 | 200 | A8III | ||
| HD 171746 | Hercules Hercules (constellation) Hercules is a constellation named after Hercules, the Roman mythological hero adapted from the Greek hero Heracles. Hercules was one of the 48 constellations listed by the 2nd century astronomer Ptolemy, and it remains one of the 88 modern constellations today... |
171746 | 91159 | 6.21 | 112 | G2Vv comp | |||
| HD 26932 | Taurus Taurus (constellation) Taurus is one of the constellations of the zodiac. Its name is a Latin word meaning 'bull', and its astrological symbol is a stylized bull's head:... |
26932 | 6.23 | 69 | G0IV | ||||
| HD 129798 | Draco Draco (constellation) Draco is a constellation in the far northern sky. Its name is Latin for dragon. Draco is circumpolar for many observers in the northern hemisphere... |
129798 | 71876 | 6.24 | 139 | F2V | DL Dra | ||
| 41 Vir | Virgo Virgo (constellation) Virgo is one of the constellations of the zodiac. Its name is Latin for virgin, and its symbol is . Lying between Leo to the west and Libra to the east, it is the second largest constellation in the sky... |
41 | 112097 | 62933 | 6.25 | 199 | A7III | ||
| χ Cet B | Cetus Cetus Cetus is a constellation. Its name refers to Cetus, a sea monster in Greek mythology, although it is often called 'the whale' today. Cetus is located in the region of the sky that contains other water-related constellations such as Aquarius, Pisces, and Eridanus.-Ecliptic:Although Cetus is not... |
χ | 53 | 11131 | 8486 | 6.72 | 78 | G0 | EZ Cet |
| HD 71974 A | Lynx Lynx (constellation) Lynx is a constellation in the northern sky, introduced in the 17th century by Johannes Hevelius. It is named after the lynx, a genus of cat. It is a very faint constellation; its brightest stars form a zigzag line.-History:... |
71974 | 41820 | 7.51 | 94 | G5 | |||
| HD 59747 | Lynx Lynx (constellation) Lynx is a constellation in the northern sky, introduced in the 17th century by Johannes Hevelius. It is named after the lynx, a genus of cat. It is a very faint constellation; its brightest stars form a zigzag line.-History:... |
59747 | 36704 | 7.70 | 64 | G5 | DX Lyn | ||
| HD 28495 | Camelopardalis Camelopardalis Camelopardalis is a large but faint constellation in the northern sky. The constellation was introduced in 1612 by Petrus Plancius. Some older astronomy books give an alternative spelling of the name, Camelopardus.-Etymology:... |
28495 | 21276 | 7.76 | 90 | G0 | MS Cam | ||
| HD 173950 | Lyra Lyra Lyra is a small constellation. It is one of the 48 constellations listed by the 2nd century astronomer Ptolemy, and remains one of the 88 modern constellations recognized by the International Astronomical Union. Its principal star, Vega — a corner of the Summer Triangle — is one of the brightest... |
173950 | 92122 | 8.08 | 121 | G5 | V595 Lyr | ||
| HIP 66459 | Canes Venatici Canes Venatici Canes Venatici is one of the 88 official modern constellations. It is a small northern constellation that was created by Johannes Hevelius in the 17th century. Its name is Latin for "hunting dogs", and the constellation is often depicted in illustrations as representing the dogs of Boötes the... |
66459 | 9.06 | 36 | K5 | Gliese 519 | |||
| HD 71974 B | Lynx Lynx (constellation) Lynx is a constellation in the northern sky, introduced in the 17th century by Johannes Hevelius. It is named after the lynx, a genus of cat. It is a very faint constellation; its brightest stars form a zigzag line.-History:... |
71974 | 41820 | 9.09 | 94 | ||||
| HD 95650 | Leo Leo (constellation) Leo is one of the constellations of the zodiac. Its name is Latin for lion. Its symbol is . Leo lies between dim Cancer to the west and Virgo to the east.-Stars:... |
95650 | 53985 | 9.68 | 38 | M0 | DS Leo, Gliese 410 | ||
| HD 238224 | Ursa Major Ursa Major Ursa Major , also known as the Great Bear, is a constellation visible throughout the year in most of the northern hemisphere. It can best be seen in April... |
238224 | 65327 | 9.72 | 82 | K5 | Gliese 509.1 | ||
| HD 13959 | Cetus Cetus Cetus is a constellation. Its name refers to Cetus, a sea monster in Greek mythology, although it is often called 'the whale' today. Cetus is located in the region of the sky that contains other water-related constellations such as Aquarius, Pisces, and Eridanus.-Ecliptic:Although Cetus is not... |
13959 | 10552 | 9.76 | 124 | K2 | Gliese 91.1 | ||
| HD 156498 | Ophiuchus Ophiuchus Ophiuchus is a large constellation located around the celestial equator. Its name is from the Greek "serpent-bearer", and it is commonly represented as a man grasping the snake that is represented by the constellation Serpens. Ophiuchus was one of the 48 constellations listed by the 2nd-century... |
156498 | 84595 | 9.98 | 271 | V2369 Oph |
Non-members
The bright, nearby star SiriusSirius
Sirius is the brightest star in the night sky. With a visual apparent magnitude of −1.46, it is almost twice as bright as Canopus, the next brightest star. The name "Sirius" is derived from the Ancient Greek: Seirios . The star has the Bayer designation Alpha Canis Majoris...
was long believed to be a member of the group, but may not be, according to research in 2003 by Jeremy King et al. at Clemson University
Clemson University
Clemson University is an American public, coeducational, land-grant, sea-grant, research university located in Clemson, South Carolina, United States....
. This research seems to indicate that it is too young to be a member.
Our Solar System
Solar System
The Solar System consists of the Sun and the astronomical objects gravitationally bound in orbit around it, all of which formed from the collapse of a giant molecular cloud approximately 4.6 billion years ago. The vast majority of the system's mass is in the Sun...
is in the outskirts of this stream, but is not a member, being about 10 times older. Our Sun
Sun
The Sun is the star at the center of the Solar System. It is almost perfectly spherical and consists of hot plasma interwoven with magnetic fields...
merely drifted in along its 250-million-year galactic orbit, and 40 million years ago was nowhere near the Ursa Major group.
External links
- http://seds.lpl.arizona.edu/messier/xtra/ngc/uma-cl.html University of Arizona website
- http://www.kencroswell.com/DescendantsOfTheDipper.html Ken CroswellKen CroswellKen Croswell is an astronomer and author living in Berkeley, California. His first degree mixed science and wider interests, majoring in physics and minoring in English literature. He also got a PhD in astronomy for studying the Milky Way's halo....
's astronomy website. - LeDrew, Glenn (1998). "AstroNotes: The Ursa Major Moving Cluster". Retrieved July 28, 2005.
- Stellar kinematic groups, Superclusters, Moving Groups - D. Montes, UCM
- http://adsabs.harvard.edu/cgi-bin/nph-bib_query?bibcode=2003AJ....125.1980K&db_key=AST&data_type=HTML&format=&high=41b4ade78800742 J.R.King et al. 2003 Astronomical Journal paper classifying group members based on Hipparcos data.