Below are listed the 93 brightest individual stars in order of their average apparent magnitudes.
For comparison, the non-stellar objects in our Solar System with maximum visible magnitudes below +2.50 are the Moon (−12.92), Venus (−4.89), Jupiter (−2.94), Mars (−2.91), Mercury (−2.45), and Saturn (−0.49).
An exact order of the visual brightness of stars is not perfectly defined for the following reasons:
- The brightnesses of all stars were traditionally based on the apparent visual magnitude as perceived by the human eye, from the brightest stars of 1st magnitude to the faintest at 6th magnitude. The invention of the telescope and the discovery of double or binary stars meant that star brightness could be individual (separate) or total (combined).
- More and more accurate instrumental photometry differentiated stellar magnitudes, often changing the order of lists of brighter stars.
- Stellar magnitude is sometimes listed by the apparent brightness of stars as seen to the naked eye as if they were single stars, as it is here. Other examples include Norton’s Star Atlas 18th Edition pg. 136.[2]
- Other stellar magnitude lists report individual stars, differentiating those in binary stars or double star systems. Often, the differences apply to the ten or hundred brightest stars. For example, the total or combined magnitude of Capella is 0.08, while Capella A and B have magnitudes of 0.76 and 0.91.
- A third kind includes the Sun as first in the magnitude listings, making Sirius 2nd, Canopus 3rd, etc. Some, like this list, place the Sun at zero, as it is not a nighttime star.
- There are sometimes small statistical variations in measured magnitudes; however, for most of the brightest stars, accurate photometry means brightness stays unchanged. These particular stars are sometimes called standard stars, which appear in the Catalogues of Fundamental Stars like the FK4, FK5 or FK6.
- Some stars, like Betelgeuse and Antares, are variable stars, changing their magnitude over days, months or years. (In the table, these are indicated with var.)
V Mag.
(m)
Bayer designation
Proper name
Distance (ly)
Spectral class
SIMBAD
0
0.000−26.74
(Sun)
0.000 016
G2 V
1
0.001−1.46
α CMa
Sirius
0008.6
A1 V
Sirius A
2
0.003−0.72
α Car
Canopus
0310
F0 Ia
Canopus
3
0.004−0.27
α Cen AB (α1,2 Cen)
Rigil Kent, Toliman[3][note 1]
0004.4
G2 V/K1 V
Alpha Centauri
4
0.005−0.04 var
α Boo
Arcturus
0037
K1.5 III
Arcturus
5
0.03
α Lyr
Vega
0025
A0 V
Vega
6
0.08
α Aur
Capella
0042
G8 III, G1 III
Capella A
7
0.12
β Ori
Rigel
0860
B8 Iab
Rigel
8
0.34
α CMi
Procyon
0011
F5 IV-V
Procyon
9
0.42 var
α Ori
Betelgeuse
0640 [4]
M2 Iab
Betelgeuse
10
0.50
α Eri
Achernar
0140
B3 Vpe
Achernar
11
0.60
β Cen
Agena, Hadar
0350
B1 III
Hadar (Agena)
12
0.77
α Aql
Altair
0017
A7 V
Altair
13
0.77
α Cru
Acrux
0320
B1 V
Acrux A
14
0.85 var
α Tau
Aldebaran
0065
K5 III
Aldebaran
15
1.04
α Vir
Spica
0260
B1 III-IV, B2 V
Spica
16
1.09 var
α Sco
Antares
0600
M1.5 Iab-b
Antares
17
1.15
β Gem
Pollux
0034
K0 IIIb
Pollux
18
1.16
α PsA
Fomalhaut
0025
A3 V
Fomalhaut
19
1.25
α Cyg
Deneb
2,600
A2 Ia
Deneb
20
1.30
β Cru
Mimosa, Becrux[note 1]
0350
B0.5 IV
Mimosa
21
1.35
α Leo
Regulus
0077
B7 V
Regulus
22
1.51
ε CMa
Adara
0430
B2 Iab
Adara
23
1.58
α Gem
Castor
0052
A1 V, A2 Vm
Castor
24
1.62
λ Sco
Shaula
0700
B1.5-2 IV+
Shaula
25
1.63
γ Cru
Gacrux
0088
M4III
Gacrux
26
1.64
γ Ori
Bellatrix
0240
B2 III
Bellatrix
27
1.68
β Tau
El Nath
0130
B7 III
El Nath
28
1.68
β Car
Miaplacidus
0110
A2 IV
Miaplacidus
29
1.70
ε Ori
Alnilam
1,300
B0 Iab
Alnilam
30
1.70
ζ Ori A
Alnitak
0820
O9 Iab
Alnitak A
31
1.74
α Gru
Alnair
0100
B7 IV
Al Na’ir
32
1.76
ε UMa
Alioth
0081
A0pCr
Alioth
33
1.78
γ2 Vel
Suhail, Regor
0840
WC8 + O7.5e
Gamma2 Velorum
34
1.79
α UMa
Dubhe
0120
K0 III, F0 V
Dubhe
35
1.80
ε Sgr
Kaus Australis
0140
B9.5 III
Kaus Australis
36
1.82
α Per
Mirfak
0590
F5 Ib
Mirfak
37
1.84
δ CMa
Wezen
1,800
F8 Ia
Wezen
38
1.85
η UMa
Benetnasch, Alkaid
0100
B3 V
Benetnasch (Alkaid)
39
1.86
θ Sco
Sargas
0270
F1 II
Sargas
40
1.86
ε Car
Avior
0630
K3 III, B2 Vp
Avior
41
1.90
γ Gem
Alhena
0100
A0 IV
Alhena
42
1.91
α Pav
Peacock
0180
B2 IV
Peacock
43
1.92
α TrA
Atria
0420
K2 IIb-IIIa
Atria
44
1.96
δ Vel
Koo She
0080
A1 V, F2-F5
Delta Velorum
45
1.97 var
α UMi
Polaris
0430
F7 Ib-II
Polaris
46
1.98
β CMa
Mirzam
0500
B1 II-III
Murzim
47
1.98
α Hya
Alphard
0180
K3 II-III
Alphard
48
2.00
α Ari
Hamal
0066
K2IIICa-1
Hamal
49
2.01
γ1 Leo
Algieba
0130
K0 IIIb, G7 IIICN
Algieba
50
2.04
β Cet
Deneb Kaitos, Diphda
0096
K0 III
Deneb Kaitos
51
2.05
κ Ori
Saiph
0720
B0.5Iavar
Saiph
52
2.06
σ Sgr
Nunki, Sadira
0220
B2.5 V
Nunki
53
2.06
θ Cen
Menkent
0061
K0IIIb
Menkent
54
2.06
α And
Alpheratz, Sirrah
0097
B8IV
Alpheratz
55
2.06
β And
Mirach
0200
M0III
Mirach
56
2.08
β UMi
Kochab
0130
K4 III
Kochab
57
2.10
α Oph
Rasalhague
0047
A5V
Ras Alhague
58
2.12 var
β Per
Algol
0093
B8V
Algol
59
2.13
β Gru
–
0170
M5 III
Beta Gruis
60
2.14
β Leo
Denebola
0036
A3 V
Denebola
61
2.15
γ And
Almach
0350
K3IIb, B9.5V
Almach
62
2.17
γ Cen
Muhlifain
0130
A1IV, (A0III/A0III)
Muhlifain
64
2.21
ζ Pup
Naos, Suhail Hadar
1,400
O5 Ia
Zeta Puppis
65
2.21
α CrB
Alphecca, Gemma
0075
A0V, G5V
Alphecca
66
2.23
λ Vel
Suhail
0570
K4.5 Ib-II
Lambda Velorum
67
2.23
γ Dra
Eltanin
0150
K5 III
Etamin
68
2.23
ζ1 UMa
Mizar
0078
A2 V
Mizar A
69
2.23
δ Ori
Mintaka
0900
O9.5 II, B0.5III
Mintaka
70
2.24
γ Cyg
Sadr
1,500
F8 Ib
Sadr
71
2.25
α Cas
Schedar
0230
K0 IIIa
Schedar
72
2.25
ι Car
Aspidiske, Turais
0690
A8 Ib
Aspidiske
73
2.27
β Cas
Caph
0054
F2 III-IV
Caph
74
2.27
ε Cen
–
0380
B1III
Epsilon Centauri
75
2.28
α Lup
Men, Kakkab
0550
B1.5 II
Alpha Lupi
76
2.29
δ Sco
Dschubba
0400
B0.2 IV
Dschubba
77
2.29
ε Sco
Wei
0065
K2 IIIb
Wei
78
2.32
η Cen
Marfikent
0310
B1.5Vne
Eta Centauri
79
2.35
β UMa
Merak
0079
A1V
Merak
80
2.37
α Phe
Ankaa, Nair al Zaurak
0077
K0 III
Ankaa
81
2.38
κ Sco
Girtab
0460
B1.5 III
Girtab
82
2.39
γ Cas
Tsih, Navi
0610
B0.5 IVe
Gamma Cassiopeiae
83
2.39
ε Boo
Izar
0202
A0
Izar
84
2.40
ε Peg
Enif
0670
K2 Ib
Enif
85
2.40
η CMa
Aludra
2,000[5]
B5 Ia
Aludra
86
2.42
β Peg
Scheat
0200
M2.3 II-III
Scheat
87
2.43
γ UMa
Phecda
0084
A0Ve SB
Phecda
88
2.43
η Oph
Sabik
0049
A1 V, A3 V
Sabik
89
2.44
α Cep
Alderamin
0049
A7 IV
Alderamin
90
2.46
κ Vel
Markeb
0540
B2 IV-V
Kappa Velorum
91
2.49
α Peg
Markab
0140
B9 III
Markab
92
2.50
ε Cyg
Gienah
0072
K0 II
Gienah
93
2.50
β Sco
Acrab
0404
B1V+B2V
Acrab
List of brightest stars – Wikipedia, the free encyclopedia
Physical properties[edit]
Size comparison between Aldebaran and the Sun.
Aldebaran is classified as a type K5III star. It is an orange giant star that has moved off the main sequence line of the Hertzsprung–Russell diagram. It has exhausted the hydrogen fuel in its core leading to core compression from gravity and helium fusion ignition through the triple-alpha fusion process.[9] Hydrogen fusion is now occurring in a shell around the helium core. The helium flash ignition expanded the star to a diameter of 44.2 times the diameter of the Sun,[4][10] approximately 61 million kilometres (see 10 gigametres for similar sizes). The Hipparcos satellite has measured it as 65.1 light years (20.0 pc) away, and it shines with 425 times the Sun’s luminosity.[3]
Aldebaran is a slightly variable star, of the slow irregular variable type LB. It varies by about 0.2 in apparent magnitude from 0.75 to 0.95.[2] With a near-infrared J band magnitude of -2.1,[1] only Betelgeuse (-2.9), R Doradus (-2.6), and Arcturus (-2.2) are brighter.
Visibility[edit]
Aldebaran is one of the easiest stars to find in the night sky, partly due to its brightness and partly due to its spatial relation to one of the more noticeable asterisms in the sky. If one follows the three stars of Orion‘s belt from left to right (in the Northern Hemisphere) or right to left (in the Southern), the first bright star found by continuing that line is Aldebaran.
Since the star is located (by chance) in the line of sight between the Earth and the Hyades, it has the appearance of being the brightest member of the more scattered Hyades open star cluster that makes up the bull’s-head-shaped asterism; however, the star cluster is actually more than twice as far away, at about 150 light years.
In this predawn occultation, Aldebaran has just reappeared on the dark limb of the waning crescent Moon (July 1997 still frame captured from video).
Aldebaran is close enough to the ecliptic to be occulted by the Moon. Such occultations occur when the Moon’s ascending node is near the autumnal equinox. This event will next occur around 2015. A reasonably accurate estimate for the diameter of Aldebaran was obtained during the September 22, 1978 occultation.[11] Aldebaran is in conjunction with the Sun around June 1 of each year.[
Aldebaran – Wikipedia, the free encyclopedia
Article topic:
Beasts of the Southern Wild
Author:
Dr Jacqui Mulville
Link:
Cardiff School of History, Archaeology and Religion
In the film Beasts of the Southern Wild, the aurochs (plural aurochsen) is a strange hybrid wild boar/bull armed with both horns and tusks that comes to symbolise the disasters that looms over Hushpuppy, her family and her community.
Early image of cave art depiction of the Aurochs
The species of animals depicted in the film are a convergence of fact, film fiction and necessity as the film makers decided that only pigs and dogs could be trained to perform to such a high standard. The pig was chosen and when merged with characteristic of the real aurochs a somewhat ambiguous animal emerged.
In reality aurochsen (latin name Bos primigenius) were wild cattle, now extinct, that once roamed across Eurasia, India, and North Africa. The last recorded aurochs died in 1627 in Poland’s Jaktorów Forest. The aurochs was far larger than most modern domestic cattle with a shoulder height of 2 metres and weighing in the region of 1,000 kilograms. To compare large domesticated cattle today are about 1.5 metres tall. Aurochs had several features rarely seen in modern cattle, such as lyre-shaped horns set at a forward angle whilst depictions and historic accounts indicate that they had a pale stripe down the spine, and sexual dimorphism of coat color. Males were black with a pale eel stripe or ‘finching’ down the spine, while females and calves were reddish.
These animals were domesticated during the Neolithic, the period when farming was invented, and gave rise to our modern domestic cattle. There were at least two domestication events one gave rise to the European cattle (known as taurine cattle) and another that gave rise to the Indian subspecies, the Zebu cattle. Other species of wild cattle, the water buffalo, the Gaur and the Banteng were also domesticated. Recent work suggests that all Eurasian cattle were descended from as few as 80 animals that were domesticated in the Near East some 10,500 years ago (Bollongino et al 2012).
These animals featured extensively in the human psyche over millennia. They are the creatures most often depicted by ancient hunters in the earliest stone age (Paleolithic) cave across Europe (e.g at Altamira and Lascaux) and were later worshipped by early farmers with their horns and skulls adorning shrines and homes (e.g. at Çatalhöyük in Turkey).
The farming site of Catalhoyuk
Aurochs are the bull that the god Zeus became, the inspiration for the Minotaur and they feature in depictions of bull leaping in ancient Crete. They were described by Julius Caesar as “a little below the elephant in size,” wrote, “and of the appearance, color, and shape of a bull. Their strength and speed are extraordinary; they spare neither man nor wild beast which they have espied.”
Welsh aurochs dating to the Mesolithic (c. 100th to 40th century BC) have been recovered from Goldcliff, with their hoof prints, and those of their human hunters along with deer, wolves and birds, found preserved in the mud of the Severn Estuary. Finds of bones attributed to aurochs on archaeological sites in England are relatively rare after the Neolithic, recent work by archaeologists at Cardiff has confirmed that the first domestic cattle (as well as sheep, pottery and monument building) appeared in Britain in the 40th to 39th century BC. The clearance of woodland, competition with domestic stock and their diseases, as well as hunting lead to the species extinction by the 10th century BC (Yalden 1999). Auroch remains are often found in marshy ground (e.g. the Porlock Auroch in Somerset) and chemical analysis has suggested that wetlands were their preferred habitat (Lynch et al 2008). To see an aurochs in Cardiff just pop down the National Museum, where they have a skull on display.
Aurochs persisted in Europe but by the 13th century A.D., their range was restricted to Poland, Lithuania, Moldavia, Transylvania and East Prussia. Their final refuge was the forests of modern day Poland, where by 1564 royal gamekeepers knew of only 38 animals. The last recorded live aurochs, a female, died in 1627 in the Jaktorów Forest from natural causes. The skull was later taken by the Swedish Army during the Swedish invasion of Poland (1655–1660) and is now the property of Livrustkammaren in Stockholm.
These animals still hold a fascination for us and there have been two notable attempts to recreate aurochs. The Heck brothers in the early 20th century merged a variety of cattle breeds, including Spanish fighting bulls to create a large, and aggressive bovid. These experiments coincided with strain of Nazi thought that sought to apply ‘pseudo-Darwinian theories in support of a racialized conception of the state’ (see the article in cabinet magazine) and eventually resulted in the reintroduction of Aurochs to Poland.
Bialowieza (including one of the Heck brothers and Goring)
More recently the Stichting Taurus (Taurus Foundation), a private Dutch organization, is leading a selective breeding program in order to recreate the extinct aurochs through a combination of modern genetic expertise and old-fashioned breeding and return the Aurochs to the mountains of Central Europe. Rather than just selecting animals that look like aurochs this project is using modern DNA analysis to characteristic the aurochs genetic identity and then run a breeding program using modern animals that contain larger quantities of aurochs DNA. To do this the project leaders have begun to argue that the reported aggressive nature of the Aurochs has been exaggerated. Like other large bovids they are unlikely to be aggressive to humans unless threatened, an important characteristic if their re-introduction to inhabited areas is being planned.
Thus the aurochs, although no longer physically present in our world, remains at large in our imagination. Their mythological status is enhanced by the early images on cave and house walls where they are painstakingly recreated with greater skill that the accompanying stick-like humans figures. In the film this imagery is drawn upon and they symbolize a threat to the human way of life. In reality it was us, the scrawny hunters, who exterminated them.
Aurochs – ‘a little below the elephant in size’ | Cardiff sciSCREEN
II Augusta was originally raised by Octavian and consul Gaius Vibius Pansa Caetronianus in 43 BC, to fight against Mark Antony; II Augusta fought in the battle of Philippi and in the battle of Perugia.
In Imperial Service[edit]
At the beginning of Augustus rule, in 25 BC, this legion was relocated in Hispania, to fight in the Cantabrian Wars, which definitively established Roman power in Hispania, and later camped in Hispania Tarraconensis. With the annihilation of Legio XVII, XVIII and XIX in the Battle of the Teutoburg Forest (AD 9), II Augusta moved to Germania, possibly in the area of Mainz. After 17, it was at Argentoratum (modern Strasbourg).
Invasion of Britannia[edit]
The legion participated in the Roman conquest of Britain in 43. Future emperor Vespasian was the legion’s commander at the time, and led the campaign against the Durotriges and Dumnonii tribes. Although it was recorded as suffering a defeat at the hands of the Silures in 52, the II Augusta proved to be one of the best legions, even after its disgrace during the uprising of queen Boudica, when its praefectus castrorum, who was then its acting commander (its legatus and tribunes probably being absent with the governor Suetonius Paulinus), contravened Suetonius’ orders to join him and so later committed suicide.
After the defeat of Boudica, the legion was dispersed over several bases; from 66 to around 74 it was stationed at Glevum (modern Gloucester), and then moved to Isca Augusta (modern Caerleon), building a stone fortress that the soldiers occupied until the end of the 3rd century. The legion also had connections with the camp at Alchester in Oxfordshire; stamped tiles record it in the 2nd century at Abonae (Sea Mills, Bristol) on the tidal shore of the Avon (Princeton Encyclopedia).
KING ALFRED AND THE DANES. KING ALFRED AND THE DANES.
sea in long open boats, high at prow and stern, anl moved by sails and oars. When they landed, the] threw up an intrenchment to defend their boats, an! then they seized all the horses they could find, an< galloped over the country, burning and pillaging fa and wide.
5. King Egbert did his best to beat off these pira tes but he died in 839, and the kings who succeeded hin were not so strong or so skilful as he was. Con sequently the Danes grew bolder. In 855 they passem a winter in the Isle of Sheppey; and from that time forward they began to settle in the country. Thai was the first step in the Danish conquest of Englani
6. Alfred was then a child. He was born in 84| the fourth son of King Ethelwulf, who succeed! Egbert. From his childhood he showed great lov of learning, but his early life was too active for hill to learn much from books.
7. Alfred’s three elder brothers were all kings I England in turn; and with the third of them, Ethii] red, Alfred shared the government. By this time tlfe Danes had practically conquered the north and eivfl of England, and it was all that Alfred and his broth* could do to defend Wessex against them. In H7| they fought nine great battles with the Danes.
8. Next year Ethelred died, and Alfred became sol king at the age of twenty-two. He had a heavy before him, for his kingdom was reduced to the wen led half of Wessex, while fresh swarms of Danes will constantly landing in England. For seven years kept up a gallant struggle, but in 878 he was fori to take refuge in the marshes of Athelney in SomerMid and was almost driven to despair.
n 1111111*m looked worst, however, Alfred i i lluil, in which he was nobly sup-,11 Wessex, and he won a decisive III.’ DiuiiHh host at Ethandun, in up I lie victory by blockading
sea in long open boats, high at prow and stern, ar moved by sails and oars. When they landed, the threw up an intrenchment to defend their boats, an then they seized all the horses they could find, an galloped over the country, burning and pillaging fa and wide.
5. King Egbert did his best to beat off these pirates but he died in 839, and the kings who succeeded him were not so strong or so skilful as he was. Con sequently the Danes grew bolder. In 855 they passep a winter in the Isle of Sheppey; and from that time forward they began to settle in the country. Thai was the first step in the Danish conquest of England
6. Alfred was then a child. He was born in 849 the fourth son of King Ethelwulf, who succeeded Egbert. From his childhood he showed great lot of learning, but his early life was too active for him to learn much from books.
7. Alfred’s three elder brothers were all kings of England in turn; and with the third of them, Ethe red, Alfred shared the government. By this time the Danes had practically conquered the north and east of England, and it was all that Alfred and his brother could do to defend Wessex against them. In 870 they fought nine great battles with the Danes.
8. Next year Ethelred died, and Alfred became sole king at the age of twenty-two. He had a heavy l a before him, for his kingdom was reduced to the western half of Wessex, while fresh swarms of Danes were constantly landing in England. For seven years he kept up a gallant struggle, but in 878 he was forced to take refuge in the marshes of Athelney in Somerset and was almost driven to despair.
just when looked worst, however, Alfred
R mighty effort, in which he was nobly sup-ported,by the men of wessex and he won a decisive battle ,he beat the host at Ethandun, in wiltshire and followed up the victory by blockading
Gaul and Roman France
French History > Gauls and romans
The area that was known as Gaul in Roman times includes modern France, and also Belgium, Luxembourg and western parts of Germany.
The conquest of the region by the Romans began in the 2nd – 1st centuries BC, and continued with the ‘Gallic Wars’, led by Julius Caesar, between 58 BC and 51 BC. At that time the region was also under threat from other directions – notably the Suevi and Helvetii tribes (from modern day Germany and Switzerland) – and initially it was defeating these tribes that posed the greatest challenge to the Romans.
![Asterix]()
It was in 53BC in Alesia that the final great battle took place between the Gauls and the Romans. The gauls, fighting under , were defeated by Julius caesar and the Romans, and the Romans can be considered to have occupied France from that date on. The exact location of Alesia is still debated, although the most likely location is in Burgundy at Alise-Sainte-Reine near Dijon.
From about 53 BC onwards the focus of the Romans in the Gallic Wars was more on suppressing a series of smaller invasions and uprisings – including 52 BC when a group of tribes led by Vercingetorix posed a significant threat to the Romans, but this threat was also defeated. (Enthusiasts of Asterix and Obelisk, the extremy popular French cartoon characters, will be familiar with this period!)
Rome then controlled the area for about six centuries, until the Roman empire itself collapsed, in the face of constant invasions.
Romans in France built a number of fine villas and, notably, introduced vines from Italy. The heyday of the Romans in Gaul was during the first and second centuries AD, when there was little unrest and the later tribal invasions from the north and east had not yet started – it was a prosperous area, with prosperity built largely on potterey, wine and food exports.
Until the Roman occupation, the predominant religion was druid based and very primitive. It was while under Roman rule that Christianity was introduced, and that Claudius I ordered the Druids suppressed. At the same time, the Gaulish language spoken underwent a fundamental transformation, and by the end of Roman rule the language spoken was a Latin based precursor of modern day French.
By the time the Romans left, to defend their homeland in the face of repeated invasions from the Visigoths, the Huns, the Vandals and others, (later as we know to prove successful), towards the end of the 5th century, the basic shape of Modern France had started to emerge. Although the Franks successfully invaded Gaul, they did little to alter the society that was by that time established. Gaul was soon established, with a King based in Paris, and the ‘modern history of France’ began.
Visiting Roman monuments in France
There are many locations in France where you can see ruins dating from the period of Roman occupation.
The greatest concentration of these, and the best place to start your exploration of Roman France, is in the south of the country near the border between Languedoc and Provence – highlights include the Pont du Gard aquaduct, the amphitheatre at Orange, and the colosseums at both Nimes and Arles, all found in
Gaul and Roman France
Regulus
From Wikipedia, the free encyclopedia
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This article is about the star. For the Roman general and consul, see Marcus Atilius Regulus. For other uses, see Regulus (disambiguation).
Regulus A/B/C
Location of Regulus (circled)
Observation data
Epoch J2000 Equinox J2000
Constellation
Leo
Right ascension
A: 10h 08m 22.311s[1]
BC: 10h 08m 12.8/14s
Declination
A: +11° 58′ 01.95″[1]
BC: +11° 59′ 48″
Apparent magnitude (V)
1.35/8.14/13.5
Characteristics
Spectral type
B7 V + K1-2 V + M5 V
U−B color index
–0.36/+0.54
B−V color index
–0.11/+0.87
Variable type
Slightly
Astrometry
Radial velocity (Rv)
+5.9 km/s
Proper motion (μ)
RA: -248.73 ± 0.35[1] mas/yr
Dec.: 5.59 ± 0.21[1] mas/yr
Parallax (π)
41.13 ± 0.35[1] mas
Distance
79.3 ± 0.7 ly
(24.3 ± 0.2 pc)
Absolute magnitude (MV)
–0.52/6.3/11.6
Details
α Leo A
Mass
3.8[2] M☉
Radius
3.092 ± 0.147[3] R☉
Luminosity
288[2] L☉
Surface gravity (log g)
3.54 ± 0.09[4] cgs
Temperature
12,460 ± 200[2] K
Rotational velocity (v sin i)
347[5] km/s
Age
≳1[6] Gyr
α Leo B/C
Mass
0.8/0.2 M☉
Radius
0.5/? R☉
Luminosity
0.31 L☉
Other designations
Alpha Leonis, 32 Leo, Cor Leonis, Basilicus, Lion’s Heart, Rex, Kalb al Asad, Kabeleced, FK5 380, GCTP 2384.00, GJ 9316, HIP 49669, HR 3982.
α Leo A: BD+12 2149, HD 87901, LTT 12716, SAO 98967.
α Leo B: BD+12 2147, HD 87884, LTT 12714, SAO 98966.
Database references
SIMBAD
data
Regulus (α Leo, α Leonis, Alpha Leonis) is the brightest star in the constellation Leo and one of the brightest stars in the night sky, lying approximately 79 light years from Earth.[1] Regulus is a multiple star system composed of four stars that are organized into two pairs. The spectroscopic binary Regulus A consists of a blue-white main-sequence star and its companion, which has not yet been directly observed, but is probably a white dwarf star.[7] Located farther away is the pair Regulus B and Regulus C, which are dim main-sequence stars.
Contents
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Observations[edit]
Of the brightest stars in the sky, Regulus is closest to the ecliptic, and is regularly occulted by the Moon. Occultations by the planets Mercury and Venus are also possible but rare, as are occultations by asteroids.
The last occultation of Regulus by a planet was on July 7, 1959, by Venus.[8] The next will occur on October 1, 2044, also by Venus. Other planets will not occult Regulus over the next few millennia because of their node positions. Regulus was occulted by the asteroid 163 Erigone in the early morning of March 20, 2014.[9][10][11] The center of the shadow path passed through New York and eastern Ontario.[9][10] However, it is unlikely that anyone saw it, due to weather. In particular, the International Occultation Timing Association recorded no successful observations at all.[12]
An occultation of Regulus by the asteroid 166 Rhodope was observed by 12 observers from Portugal, Spain, Italy, and Greece on October 19, 2005.[13]
Although best seen in the evening in northern hemisphere in late winter and spring, Regulus can be found at some time of night throughout the year except for about a month on either side of August 22, when the sun is too near.[14] Regulus passes through SOHO‘s LASCO C3 every August.[15] For most Earth observers, the heliacal rising of Regulus occurs in the first week of September. Every 8 years, Venus passes Regulus around the time of the star’s heliacal rising, as on 5 September 2014.
The primary of Regulus A has about 3.5 times the Sun’s mass and is a young star of only a few hundred million years. It is spinning extremely rapidly, with a rotation period of only 15.9 hours, which causes it to have a highly oblate shape.[16] This results in so-called gravity darkening: the photosphere at Regulus’ poles is considerably hotter, and five times brighter per unit surface area, than its equatorial region. If it were rotating only 10% faster, the star’s gravity would be insufficient to hold it together, and it would spin itself apart.[17]
Regulus is a multiple star system consisting of four stars. Regulus A is a binary star consisting of a blue-white main sequence star of spectral type B7V, which is orbited by a star of at least 0.3 solar masses, which is probably a white dwarf. The two stars take approximately 40 days to complete an orbit around their common centre of mass. Given the extremely distorted shape of the primary, the relative orbital motion may be notably altered with respect to the two-body purely Keplerian scenario because of non-negligible long-term orbital perturbations affecting, for example, its orbital period. In other words, the third Kepler law, which holds exactly only for two pointlike masses, would be no longer valid because of the highly distorted shape of the primary.
At a distance of around 4,200 AU[citation needed] from Regulus A is a binary star system that shares a common proper motion. Designated Regulus B and Regulus C, the Henry Draper Catalogue number for this pair is HD 87884. The first is a K2V star, while the companion is approximately M4V.[16] The companion pair has an orbital period of 2,000 years and is separated by about 100 AU.[citation needed]
Visibility[edit]
The Regulus system as a whole is the twenty-first brightest star in the night sky with an apparent magnitude of +1.35. The light output is dominated by Regulus A. Regulus B, if seen in isolation, would be a binocular object of magnitude +8.1, and its companion, Regulus C, the faintest of the three stars that has been directly observed, would require a substantial telescope to be seen, at magnitude +13.5. Regulus A is itself a spectroscopic binary: the secondary star has not yet been directly observed as it is much fainter than the primary. The BC pair lies at an angular distance of 177 arc-seconds from Regulus A, making them visible in amateur telescopes[citation needed].
Etymology and cultural associations[edit]
Rēgulus is Latin for ‘prince’ or ‘little king’. The Greek variant Basiliscus is also used. It is known as Qalb al-Asad, from the Arabic قلب الأسد, meaning ‘the heart of the lion’. This phrase is sometimes approximated as Kabelaced and translates into Latin as Cor Leōnis. It is known in Chinese as 轩辕十四, the Fourteenth Star of Xuanyuan, the Yellow Emperor. In Hindu astronomy, Regulus corresponds to the Nakshatra Magha (“the bountiful”).
Babylonians called it Sharru (“the King”), and it marked the 15th ecliptic constellation. In India it was known as Maghā (“the Mighty”), in Sogdiana Magh (“the Great”), in Persia Miyan (“the Centre”) and also as Venant, one of the four ‘royal stars‘ of the Persian monarchy. [18] It was one of the fifteen Behenian stars known to medieval astrologers, associated with granite, mugwort, and the kabbalistic symbol 
.
In MUL.APIN, Regulus listed as LUGAL, meaning “the star that stands in the breast of the Lion:the King.”.[19]
Regulus – Wikipedia, the free encyclopedia
