Leo

From All Skies Encyclopaedia

Authors: Susanne M Hoffmann, Youla Azkarrula, Doris Vickers, IanRidpath

star chart
Leo star chart (IAU and Sky & Telescope magazine, Roger Sinnott & Rick Fienberg).
Λέων (Leon)
Asterism Info
Native
Λέων
RomanisationLeon
Translation
Lion
Position (2000)
Right ascension141.1635778 to 177.26490979999997
Declination6.02932167 to 26.18232429
Area478.44 sq. deg.
Stars
Bright stars62
Bayer/Flamsteed
stars		46
Stars brighter than 3.00m5
Brightest starRegulus (1.4m)
Taxonomy
category
of asterism		Almagest constellation
IAU-
constellations		Leo

One of the 88 IAU constellations with Greco-Roman background. It has been developed from a Babylonian predecessor (UR.GU.LA). The constellation lies in the zodiac and was therefore adopted from Greek astronomy around the middle of the 1st millennium BCE from Babylon. In Mesopotamia a millennium earlier, however, it was not named directly after an animal: the Sumerian word UR.GU.LA refers to a demon that looks like a winged lion, as depicted on a clay tablet as a scratch drawing.

Etymology and History

Kugel Globe: Cancer, Leo, Hydra, Virgo (drawing by SMH 2024)[1], cf WGSN 2025[2].

Origin of Constellation

[3]In the 1st millennium, a uranography describes two figures in this region of the sky: a lion (UR.MAḪ) and this demon, the winged lion (UR.GU.LA). However, according to current knowledge, this pairing of terms has only been documented once. Another text from the 1st millennium can be understood as equating the two figures, and yet another speaks of a rear and a front demon lion. It is still unclear what transformations the demon underwent to become a normal lion. In any case, the foreign Greek culture certainly did not understand the demon, and at that point at the latest, the two figures were equated and the wings removed.

It is noteworthy that the lion, as we imagine it today, lies only north of the ecliptic. The lion's body consists of a trapezoid of bright stars, the southernmost of which, Regulus, lies less than a moon's diameter north of the ecliptic. It can therefore be covered by the sun and moon. The lion's front paws lie south of the ecliptic, but there is a large gap between its hind paws and the ecliptic – or even the neighbouring southern constellation. Assyriologists have therefore suggested that the doubling in Babylonian uranography was an attempt to close this gap. According to this, the second lion would be interpreted as lying south of today's constellation Leo.

However, on the microzodiac clay tablet in the Museum of the Ancient Near East in Berlin, it is clear to see that the winged lion is walking on a Musch snake (mul (d)MUŠ). The tablet dates from the Seleucid period (i.e. the period of Greek rule) and shows the image as it was already described in MUL.APIN about 1.5 millennia earlier: There is nothing between the winged lion and the snake we call Hydra.

This was no different in Greek constellation culture – except that the lion had no wings. It was not until the advent of telescope surveys in the 17th century that a new constellation of faint stars was defined in the ‘nothingness’ beneath the lion: the Sextans, The Sextant.

Leo and Virgo above the MUŠ-Dragon, two claytablet drawings from the Seleucid era (roughly 2nd century BCE), CC BY SMH based upon the drawings by E. Weidner (1967) and Thureau-Dangin (1922).

Babylonian

see

  • winged lion on kudurru H9095
    winged lion on kudurru H9095
  • winged lion on kudurru SB22 (Louvre)
    winged lion on kudurru SB22 (Louvre)
  • winged lion on Sb22
    winged lion on Sb22
  • Leo on Mesopotamian seal print, Wallenfels (1993)
    Leo on Mesopotamian seal print, Wallenfels (1993)

Greco-Roman

Egyptian

In Ptolemaic times (1st century BCE), when Egypt was ruled by the Romans, new Egyptian temples were built: a Chnum temple in Esna and a Hathor temple Dendera (south and north of Thebes/ Luxor). They display a cultural mixture of Babylonian and Egyptian constellations.

Aratos

Beneath the Bear’s head are the Twins, beneath her belly the Crab, and under her hind legs the Lion shines brightly. This is where the sun’s track is hottest, [150] and the fields are seen bereft o f their corn-ears when the sun first comes into conjunction with the Lion. This is the time when the whistling etesian winds sweep strongly across the broad sea, and it is no longer seasonable for ships to be under oars. Then let broad-beamed ships be my pleasure, [155] and let helmsmen hold their steering-oars into the wind. (Kidd 1997)

Eratosthenes

Pamias and Zucker (2013,[4] 38-40)

Var. 1: It is one of the most prominent constellations. Apparently, the zodiacal Lion was granted this honour by Zeus because it ranks first among four-legged animals. Some <say> that it represents the first labour performed by Heracles.

Leo has three stars on its head, two on its neck, one on its chest, three on its back, one bright star on its tail, two beneath its chest, and one on its forepaw. Thirteen in all.

Var. 2: It is one of the most prominent constellations. Apparently, the zodiacal Lion was granted this honour by Zeus because it ranks first among four-legged animals. Some say it represents the first labour accomplished by Heracles, placed there so that the memory might be preserved. It is indeed the only animal he killed unarmed, for the love of glory, by suffocating it in his arms. Pisander of Rhodes recounts this episode. Hence Heracles wears the lion’s skin, a sign of the illustrious feat he accomplished. This is the lion that was killed by Heracles at Nemea.

The Lion has three stars on its head, one on its chest and two below, a bright one on its right paw, one in the middle of its belly, another below, one on its hip, one on its hind knee, a bright one at the tip of its paw, two on its neck, three on its back, one in the middle of its tail, and a bright one at the tip of its tail. Nineteen in all.

Leo and the "triangle near the tail"; rectangular zodiac of Dendera

Above the Lion, one can also see seven dim stars forming a triangle towards the tail. They are called “the Hair of Berenice the Benefactor”.

Eratosthenes's star catalogue can be reconstructed from the list of stars he mentions in the last section of each of the constelllation descriptions. Hoffmann (2017)[5] made such a catalogue and used it for computational comparison with Hipparchus's, Ptolemy's and Babylonian data; it is based on the edition and translation by Pamias and Geus (2007)[6] and presented here in English translation.

erat.Cat.ID constStarID starName ident.Bayer ident.HIP certainty
180 1 three stars on the head eps Leo 47908 1
181 2 three stars on the head mu Leo 48455 1
182 3 three stars on the head lambda Leo 46750 1
183 4 one on the chest alpha Leo 49669 1
184 5 two below the chest 31 Leo 49637 1
185 6 two below the chest pi Leo 49029 1
186 7 one bright one on the right paw 2 Sex (although it is only 4.6 mag, there are no bright stars left that have not already been assigned - unless he counted something twice...) 47310 1
187 8 one in the middle of the belly rho Leo 51624 1
188 9 one below the belly 48 Leo 51775 2
189 10 one on the hip theta Leo 54879 1
190 11 one on the rear knee sigma Leo 55434 1
191 12 one bright one on the tip of the paw omikron Leo 47508 1
192 13 two on the nape zeta Leo 50335 1
193 14 two on the nape gamma1 Leo 50583 1
194 15 three on the back m Leo 52686 1
195 16 three on the back b Leo 53954 1
196 17 three on the back delta Leo 54872 1
197 18 one bright one at the end beta Leo 57632 1
198 1 above the Lion seven dim stars, which form a triangle at the tail and are called the locks of the benefactress Berenice gamma Com 60742 1
199 2 above the Lion seven dim stars, which form a triangle at the tail and are called the locks of the benefactress Berenice 12 Com 60351 1
200 3 above the Lion seven dim stars, which form a triangle at the tail and are called the locks of the benefactress Berenice 14 Com 60697 1
201 4 above the Lion seven dim stars, which form a triangle at the tail and are called the locks of the benefactress Berenice 17 Com 60904 1
202 5 above the Lion seven dim stars, which form a triangle at the tail and are called the locks of the benefactress Berenice 23 Com 61394 1
203 6 above the Lion seven dim stars, which form a triangle at the tail and are called the locks of the benefactress Berenice 7 Com 59847 1
204 7 above the Lion seven dim stars, which form a triangle at the tail and are called the locks of the benefactress Berenice 16 Com 60746 1
Hipparchus
Rising (Lib III Cap III §2)

The Rising of ...

east south
lam1 lam2 lam1 lam2
Cnc 7 1/2 Leo 18 1/2 Psc 20 Tau 11 1/2
star of those in the head the northern of the front ones the one in the hind feet
duration 3 1/4 hours = 195 min = 48 3/4 degree
Setting (Lib II Cap VI §10)
west south
lam1 lam2 lam1 lam2
Cnc 20 1/2 Vir 14 Sco 13 Sgr 20 1/2
star the one in the front feet the one at the tip of the tail
duration 2 2/3 hours = 160 min = 40°
Hipparchus's "lost" star Catalogue

The star catalogue of Hipparchus is not preserved. Yet, several scholars have reconstructed it in the past century: Vogt (1925)[7], Grasshoff (1990)[8], Hoffmann (2017)[9] and Glover (2026)[10]. Grasshoff's catalogue and computations are not published digitally, Hoffmann published three versions of the Manitius+Hoffmann[11] star lists in the CDS VizieR "catalog of catalogs", and Glover printed the star lists constellationwise in his book.

Hipparchus's star in Aquarius (Glover 2026)
hipp.Cat.ID constStarID starName ident.Bayer ident.HIP concordance
348 1 α Leo 49669 CPAE
349 2 β Leo 57632 CPAE
350 3 γ Leo (γ1) 50583 CPAE
351 4 δ Leo 54872 CPAE
352 5 ε Leo 47908 CPAE
353 6 ζ Leo 50335 CPAE
354 7 η Leo 49583 CPAE
355 8 θ Leo 54879 CPAE
356 9 ι Leo 55642 CPAE
357 10 κ Leo 46146 CPAE
358 11 λ Leo 46750 CPAE
359 12 μ Leo 48455 CPAE
360 13 ν Leo 48883 CPAE
361 14 ο Leo 47508 CPAE
362 15 ρ Leo 51264 CPAE
363 16 σ Leo 55434 CPAE
364 17 b Leo 53954 CPAE
365 18 m Leo 52686 CPAE
366 19 72 Leo 54951 CPAE
Hyginus, Astronomica

He is said to have been put among the stars because he is considered the king of beasts. Some writers add that Hercules' first Labor was with him and that he killed him, unarmed. Pisandrus and many others have written about this. Above his likeness in the sky nearest the Virgin are seven other stars near his tail, arranged in a triangle, which Conon, the mathematician, and Callimachus call the Lock of Berenice. When Ptolemy had married his sister Berenice, daughter of Ptolemy and Arsinoe, and after a few days had set out to attack Asia, Berenice vowed that if Ptolemy returned as victor she would clip off her hair. She placed the lock, consecrated by this vow, in the temple of Venus Arsinoe Zephyritis, but on the following day it couldn't be seen there. When the king was distressed by this, Conon the mathematician, whom we mentioned above, desiring to win the favor of the king, said that he had seen the lock among the constellations, and pointed out seven stars without definite configuration which he imagined were the lock. Some authors along with Callimachus have said that this Berenice raised horses, and used to send them to Olympia. Others add that once Ptolemy, Berenice's father, in panic at the number of the enemy, had sought safety in flight, but his daughter, an accomplished horsewoman, leaped on a horse, organized the remaining troops, killed many of the enemy, and put the rest to flight. For this even Callimachus calls her high-souled. Eratosthenes says that she ordered returned to the girls of Lesbos the dowry left to them by their parents, which no one had released, and she established among them right to bring action of recovery. (Mary Ward 1960)

Geminos

Almagest Δέοντος.

id Greek

(Heiberg 1898)

English

(Toomer 1984)

ident.
Λέουτος ἀστεριῦμόρ. Constellation of Leo
1 ὁ ἐπ’ ἄκρου τοῦ μοκτῆρος. The star on the tip of the nostrils kap Leo
2 ὁ ἐν τῷ χάσματι The star in the gaping jaws lam Leo
3 τῶν ἐν τῇ κεφαλῇ β ὁ βορειότερος. The northernmost of the two stars in the head mu Leo
4 ὁ νοτιώτερος αὐτῶν. The southernmost of these eps Leo
5 τῶν ἐν τῷ τραχήλῳ ἡ’ ὁ βόρειος The northernmost of the 3 stars in the neck zet Leo
6 ὁ ἐχόμευος καὶ μέσος τῶν τριῶν. The one close to this, the middle one of the three gam Leo
7 ὁ φότιος αὐτῶν The southernmost of them eta Leo
8 ὁ ἐπὶ τῆς καρδίας καλούμευος Βασιλίσκος. The star on the heart, called 'Regulus' alf Leo
9 ὁ φοτιώτερος αὐτοῦ καὶ ὡς ἐπὶ τοῦ στήθους The one south of this, about on the chest 31 Leo
10 ὁ μικρῷ προηγούμευος τοῦ ἐπὶ τῆς καρδίας. The star a little in advance of the star on the heart nu Leo
11 ὁ ἐπὶ τοῦ δεξιοῦ χόνατος The star on the right knee psi Leo
12 ὁ ἐπὶ τῆς ἐμπροσθίας δεξιᾶς δρακός The star on the right front claw-clutch xi Leo
13 ὁ ἐπὶ τῆς ἐμπροσθίας καὶ ἀριστερᾶς δρακός. The star on the left front claw-clutch omi Leo
14 ὁ ἐπὶ τοῦ ἀριστεροῦ γόρατος. The star on the left [front] knee pi Leo
15 ὁ ἐπὶ τοῦ ἀριστεροῦ γόρατος. The star on the left armpit rho Leo
16 τῶν ἐν τῇ γαστρὶ τριῶν ὁ προηγούμενος. The most advanced of the three stars in the belly 46 Leo
17 τῶν λοιπῶν καὶ ἐπομένων β’ ὁ βόρειος. The northernmost of the other, rearmost 2 52 Leo
18 ὁ νοτιώτερος αὐτῶν. The southernmost of these [two] 53 Leo
19 τῶν ἐπὶ τῆς ὀσφύος β ὁ προηγούμενος. The more advanced of the two stars on the rump 60 Leo
20 ὁ ἑπόμενος αὐτῶν The rearmost of them del Leo
21 τῶν ἐκ τοῦς χλουτοῖς β’ ὁ βορειότερος. The northernmost of the 2 stars in the buttocks 81 Leo
22 ὁ νοτιώτερος αὐτῶν The southernmost of them tet Leo
23 ὁ ἐν τοῖς ὀπισθομήροις.. The star in the hind thighs iot Leo
24 ὁ ἐν ταῖς ὀπισθίαις ἀγκύλαις The star in the hind leg-bends sig Leo
25 ὁ τούτου νοτιώτερος ὡς ἐ» τοῦς πήχεσι The one south of this, about in the lower legs tau Leo
26 ὁ ἐπὶ τῶν ὀπισθύων δρακῶν. The star on the hind claw-clutches ups Leo
27 ὁ ἐπ’ ἄκρας τῆς οὐρᾶς The star on the end of the tail bet Leo
ἀστέρες κξ, ὧν αἱ μεγέθους β, β’ β, γ’ς, δ’η, ε' ε, ς' ὅ. {27 stars, 2 of the first magnitude, 2 of the second, 6 of the third, 8 of the fourth, 5 of the fifth, 4 of the sixth}
Οἱ περὶ τὸν Λέουτα ἀμόρφωτοι. Stars around Leo outside the constellation:
28 ὁ τῶν ὑπὲρ τὸν νῶτον β ὁ προηγούμευος The more advanced of the 2 over the back 41 LMi
29 ὁ ἐπόμευος αὐτῶν The rearmost of them 54 Leo
30 τῶν ὑπὸ τὴν λαγόνα τ’ ὁ βόρειος. The northernmost of the 3 under the flank chi Leo
31 ὁ μέσος αὐτῶν. The middle one of these 59 Leo
32 ὁ νότιος αὐτῶν The southernmost of them 58 Leo
33 τῆς μεταξὺ τῶν ἄκρων τοῦ Λέουτος καὶ τῆς Ἄρκτου κεφελοειδοῦς σοστροφῆς καλουμένου Πλοκάμου τὸ βορειότατον The northernmost part of the nebulous mass between the edges of Leo and Ursa [Major], called Coma [Berenices] 15 Com
34 τῶν νοτίων τοῦ Πλοκάμου ἐξοχῶν ἡ προηγουμένη The most advanced of the southern outrunners of Coma 7 Com
35 ἡ ἐπομένη αὐτῶν ἐν σχήματι φύλλου κισσίνου The rearmost of them, shaped like an ivy leaf 23 Com
ἀστέρες ἐ, ὧν δ’ μεγέθους ἂ, ε’ ὃ, καὶ ὁ Πλόκαμος. {5 stars, 1 of the fourth magnitude, 4 of the fifth, plus Coma}
Convex Hull for the stars inside Leon (CC BY Youla Azkarrula).
Stars within the Constellation Area
id Label IAU design. description Vmag
1 Regulus HIP 49669 Constellation lines 1.4
2 Algieba HIP 50583 Constellation lines 1.98
3 Denebola HIP 57632 Constellation lines (Vertex) 2.13
4 Zosma HIP 54872 Constellation lines (Vertex) 2.53
5 ϵ Leonis HIP 47908 Constellation lines 2.98
6 Chertan HIP 54879 Constellation lines 3.35
7 η Leonis HIP 49583 Constellation lines 3.41
8 Adhafera HIP 50335 Constellation lines 3.41
9 Subra HIP 47508 Constellation lines (Vertex) 3.52
10 Shaomin HIP 51624 Inside the hull 3.87
11 Rasalas HIP 48455 Constellation lines (Vertex) 3.88
12 ι Leonis HIP 55642 Constellation lines 4.01
13 σ Leonis HIP 55434 Constellation lines (Vertex) 4.04
14 Alterf HIP 46750 Constellation lines 4.31
15 Yunü HIP 49637 Inside the hull 4.38
16 60 Leo HIP 53954 Inside the hull 4.398
17 κ Leonis HIP 46146 Constellation lines (Vertex) 4.46
18 χ Leonis HIP 54182 Inside the hull 4.62
19 π Leonis HIP 49029 Constellation lines (Vertex) 4.7
20 - HIP 50564 Inside the hull 4.76
21 ν Leonis HIP 48883 Inside the hull 5.26
22 - HIP 48390 Inside the hull 5.28
23 53 Leo HIP 52911 Inside the hull 5.312
24 73 Leo HIP 55016 Inside the hull 5.32
25 ψ Leonis HIP 47723 Inside the hull 5.35
26 37 Leo HIP 50333 Inside the hull 5.41
27 46 Leo HIP 51585 Inside the hull 5.46
28 52 Leo HIP 52689 Inside the hull 5.478
29 51 Leo HIP 52686 Inside the hull 5.492
30 81 Leo HIP 55765 Inside the hull 5.572
31 44 Leo HIP 51008 Inside the hull 5.61
32 18 Leo HIP 47959 Inside the hull 5.644
33 EO Leo HIP 49220 Inside the hull 5.663
34 8 Leo HIP 47189 Inside the hull 5.732
35 85 Leo HIP 56080 Inside the hull 5.734
36 - HIP 55716 Inside the hull 5.788
37 * 49 Leo A HIP 51802 Inside the hull 5.79
38 36 G. Leo HIP 54863 Inside the hull 5.793
39 39 Leo HIP 50384 Inside the hull 5.82
40 10 Sex HIP 48734 Inside the hull 5.848
41 90 Leo HIP 56473 Inside the hull 5.94
42 - HIP 50319 Inside the hull 5.96
43 - HIP 50174 Inside the hull 6.02
44 11 Sex HIP 48876 Inside the hull 6.033
45 45 Leo HIP 51213 Inside the hull 6.04
46 20 Leo HIP 48218 Inside the hull 6.077
47 - HIP 51161 Inside the hull 6.132
48 42 Leo HIP 50755 Inside the hull 6.163
49 13 Leo HIP 47550 Inside the hull 6.249
50 - HIP 46938 Inside the hull 6.25
51 - HIP 56242 Inside the hull 6.26
52 - HIP 52513 Inside the hull 6.266
53 - HIP 54688 Inside the hull 6.295
54 - HIP 49445 Inside the hull 6.36
55 - HIP 54319 Inside the hull 6.392
56 34 Leo HIP 49929 Inside the hull 6.427
57 19 Leo HIP 48029 Inside the hull 6.445
58 23 Leo HIP 48324 Inside the hull 6.45
59 - HIP 47779 Inside the hull 6.47
60 - HIP 48023 Inside the hull 6.49
61 - HIP 52484 Inside the hull 6.5
62 - HIP 53737 Inside the hull 6.52

Transfer and Transformation of the Constellation

  • (1952) H.A. Rey's stick figure of Leo
    (1952) H.A. Rey's stick figure of Leo
  • (1988) O. Hlad's stick figure of Leo
    (1988) O. Hlad's stick figure of Leo

Mythology

Greek[3]

Eratosthenes speculates that Zeus may have placed this constellation in the sky because the lion rules over four-legged animals. However, he adds that some people believe it to be the lion of Nemea, which Heracles strangled with his bare hands in his first of twelve labours. This lion is said to have been a dangerous beast.

Heracles was first given ten tasks by King Eurystheus to rid the world of certain evils. After these tasks were completed, he was given two more. The first of all tasks was to rid Nemea of the beast.

Eratosthenes recounts that Heracles chose not to use weapons for this task because he considered it particularly glorious. Later, he kept the lion's skin as a trophy for this heroic deed. On star charts, he is therefore often depicted either carrying it over his arm or wearing it as a cloak – with the lion's head on his head.

References

  1. ↑ Hoffmann (2025), Some Results on the Ancient Globes, Globe Studies – The Journal of the International Coronelli Society, 69, 4169.
  2. ↑ Susanne M. Hoffmann,* Khalid AlAjaji, B.S. Shylaja, Yang Boshun, Danielle Adams, Eric Mamajek, Ian Ridpath, Paul Baki, Juan Antonio Belmonte Avilés, Sze-Leung Cheung, Daniel Cunnama, Jörg Matthias Determann, M. Sadegh Faghanpour, Steven Gullberg, Duane Hamacher, Roland Laffitte, Alejandro M. López, Javier Mejuto, Thierry Montmerle, Clive Ruggles, Shi Yunli, Doris Vickers, Sun Xiaochun, and Hitoshi Yamaoka (2025). The IAU Working Group on Star Names (WGSN): Research Finds in 2025. Journal of Astronomical History and Heritage, 28(4), 1026–1038 (2025).
  3. ↑ 3.0 3.1 Hoffmann, Susanne M. Wie der Löwe an den Himmel kam. Franckh Kosmos Verlag, Stuttgart 2021
  4. ↑ Pamìas, Jordi und Zucker, Arnaud (2013). Ératosthènes de Cyrène: Catastérrismes, Belles Lettres, Paris
  5. ↑ Hoffmann, S. M., <i>Hipparchs Himmelsglobus</i>. Springer Wiesbaden/ New York, 2017. doi:10.1007/978-3-658-18683-8.
  6. ↑ Eratosthenes: Sternsagen, übersetzt von Pamìas, Jordi und Geus, Klaus, Verlag Utopica, Oberhaid 2007
  7. ↑ Vogt, H., “Versuch einer Wiederherstellung von Hipparchs Fixsternver zeichnis”, <i>Astronomische Nachrichten</i>, vol. 224, no. 2, Wiley, p. 17, 1925. doi:10.1002/asna.19252240202.
  8. ↑ Graßhoff, G., <i>The History of Ptolemy's Star Catalogue</i>, Springer, New York, 1990
  9. ↑ Hoffmann, S. M., <i>Hipparchs Himmelsglobus</i>. Springer Wiesbaden/ New York, 2017. doi:10.1007/978-3-658-18683-8.
  10. ↑ Glover, E. (2026). The Astronomy of Hipparchus, Cambridge University Press
  11. ↑ Hipparchus's Lost Star Catalogue (1/2 reconstructed) (Hoffmann, 2017) in VizieR
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