Hydra

Authors: Susanne M Hoffmann, Youla Azkarrula, Doris Vickers, Roland Laffitte

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IAU Hydra chart

Babylonian predecessor of Hydra: MUŠ, a creature with a snake-body with a wing, a dog-head and front legs; painting by Jessica Gullberg, in Stellarium by Susanne M Hoffmann

clay tablets VAT 7847+AO6448

Hydra (as a vessel) with Corvus and Crater on the Farnese Globe (2nd century CE), mapped to Stellarium by SMH 2021.

One of the 88 IAU constellations. The name "Hydra" refers to a watersnake from Greek mythology. Still, the underlying constellation originally referred to a Babylonian creature that consisted of a dog-headed snake with wings, the ^{mul (d)}MUŠ. For Aratos and Eratosthenes, the constellations Hydra, Corvus, and Crater belong together; they form a super-constellation consisting of several figures. They tell a star legend whose main character is the raven, who is said to have carried the Hydra to Apollo. However, this contradicts the figure in the sky: the raven is tiny compared to the Hydra and looks more like it is riding on it. This legend testifies to the actually foreign origin of the constellation: The giant snake and the raven were adopted as an image from Mesopotamia. The description or listing of these figures is already documented in MUL.APIN in the 2nd millennium BCE. It is one of the few constellations for which there is even evidence of an engraving from Mesopotamia – although only from the Seleucid period, i.e., under Greek rule.

Etymology and History

The Greek constellation of the Water Snake is a derivative of the Babylonian constellation of the MUŠ-Dragon, a dog-headed creature with the body of a gigantic snake with front legs and wings.

Origin of Constellation

The Babylonian constellation is mentioned as early as 2nd millennium BCE; it occurs in lexical texts and texts of the Three Stars Each-genre. It is also mentioned in the first list (uranology) of MUL.APIN, where the Raven (or Crow) is mentioned at the tip of the tail of the huge creature in the sky.

Aratus

Constellation Hydra with Crater and Corvus on the Kugel Globe (1st century BCE), detail from drawing by SMH.

But yet another constellation sweeps across the horizon: they call it the Hydra. Like a living thing [445] it winds at great length, its head comes below the middle of the Crab, its coil under the Lion’s body, and its tail hangs over the Centaur himself. On its middle coil lies the Bowl, and on the last one the figure of a Raven that looks like one pecking the coil. [450] Yes, and there too Procyon shines brightly beneath the Twins. (Kidd 1997)

For Aratus pi Hya is part of the snake which can be derived from the simultaneously setting constellations (663).

Eratosthenes

Eratosthenes in his Catasterismi gives two sections per constellation: First, he describes the story that led to the object/ animal/ god becoming a constellation. Then, he describes the positions of the stars in the figure.

This constellation is plural because of one event event. The raven is associated with the cult of Apollo, as a bird is dedicated to each of the gods. As the gods were making a sacrifice, he was sent to a fountain to collect a libation; seeing a fig tree near the fountain bearing figs that were unripe figs, he waited for them to ripen; after a while, when they were time, when they were ripe and he had eaten the figs, realising eaten the figs, realising that he had committed a sacrilege, he also seized the hydra that was in the fountain and brought it with the cup, claiming that the hydra had been drinking day after day from the spring. But Apollo discovered what had happened and imposed on the raven a punishment commensurate with his fault : to be thirsty among men at this time of year as Aristotle says in his books On Beasts. For leave a clear reminder of the sacrilege that had been committed against the gods, Apollo represented and placed among the constellations the Hydra, the Crater, and the Raven who cannot drink from it or go near it. The Hydra has three bright stars on the tip of its head head, six on its first fold, the last of which is bright, three on the second fold, four on the third, two on the fourth, and nine stars without brilliance which go from the fifth fold to the tail. In all, twenty-seven. The Raven is located on the tail of Hydra and looks towards the setting sun. It has a star without luster on the beak, two on the wing, two on the rump, and one on the tip of the legs. In all, seven. The Crater is located on the Hydra, at a certain distance from the fold, and is inclined towards the knees of the the Virgin. The Crater has two stars without luster on the rim, two in the centre of the Cup, and two at the the base. In all, six. (Pamias and Zucker 2013)

English (our translation)

Hydra to which also belongs the Cup and the Raven

This constellation is plural [a super-constellation] because of one event. The raven is associated with the cult of Apollo, as a bird is dedicated to each of the gods. As the gods were making a sacrifice, he was sent to a fountain to collect a libation; seeing a fig tree near the fountain bearing figs that were unripe, he waited for them to ripen. At the time, when they were ripe and he had eaten the figs. Realising that he had committed a sacrilege, he also seized the watersnake (hydra) that was in the fountain and brought it with the cup, claiming that the hydra had been drinking day after day from the spring. But Apollo discovered what had happened and imposed on the raven punishment commensurate with his fault: to be thirsty among men at this time of the year, as Aristotle says in his books On the Animals. For the sacrilege that had been committed against the gods, Apollo placed the Hydra, the Crater, and the Raven, who cannot drink or bath among the constellations.

The Hydra has three bright stars on the tip of its head, six on its first fold, the last of which is bright, three on the second fold, four on the third, two on the fourth, and nine stars without brilliance which go from the fifth fold to the tail. In all, twenty-seven. The Raven is located on the tail of Hydra and looks towards the setting sun. It has a star without luster on the beak, two on the wing, two on the rump, and one on the tip of the legs. In all, seven. The Crater is located on the Hydra, at a certain distance from the fold, and is inclined towards the knees of the Virgin. The Crater has two stars without luster on the rim, two in the centre of the Cup, and two at the base.

Hipparchus

Greek (Manitius 1894)	German (Manitius 1894)	English
	weiter giebt Eudoxos auch die auf den sogenannten Kolurkreisen gelegenen Sterne an und behauptet, auf dem einen derselben liege die Mitte des Großen Bären, die Mitte des Kreises, der Nacken der Wasserschlange und von der Argo das Stück zwischen dem Hinterteil und dem Mastbaum; alsdann nach dem unsichtbaren Pol der Schwanz des südlichen Fisches, die Mitte des Steinbocks und die Mitte des Pfeils; endlich gehe er durch den Hals und den rechten Flügel des Schwans, durch die linke Hand des Kepheus, durch die Windung der Schlange und vorbei am Schwanze des Kleinen Bären.	Eudoxus also gives the stars situated on the so-called circles of Colur and claims that on one of them lies the centre of the Great Bear, the centre of the circle, the neck of the watersnake and the part of the Argo between the rump and the mast; then, after the invisible pole, the tail of the southern fish, the centre of Capricorn and the centre of the arrow; finally, it passes through the neck and the right wing of the swan, through the left hand of Cepheus, through the coil of the Snake and past the tail of the Little Bear.	Lib. I. Cap. XL § 9 .
	Ersichtlich macht er dies auch bei dem Aufgange der Fische, wo er sich also ausdrückt; nachdem er nämlich von der Wasserschlange gesagt, daß das Stück vom Kopfe bis zur ersten Windung, wenn der Wassermann im Aufgange begriffen ist, nicht mehr über dem Horizont sei, während den Rest ihres Körpers die Fische hinabführen.	He also makes this evident in the rising of the fishes, where he expresses himself thus; for after he has said of the watersnake that the part from the head to the first coil, when the Aquarius is in the act of rising, is no longer above the horizon, while the rest of its body is led down by the fishes.	Lib. II. Cap. I. § 24
	Untergang des Perseus, mitkulminierend: Leo 5 1/2: Von der Wasserschlange der vierte von den vier hinter dem hellen nach Osten gelegenen (λ2), 1 Mbr. westlich des Meridians.	Setting of Perseus, co-culminating: Leo 5 1/2: Of the watersnake the fourth of the four behind the bright one to the east (λ2), 1 moon width west of the meridian.	Lib. II, Cap.VI. §15
	Aufgang des Kentaur, mitkulminierend: Cnc 12°: Von der Wasserschlange der nachfolgende in der südlichen Kinnlade (η)	Rising of the centaur, co-culminating: Cnc 12°: From the watersnake of the following in the southern jaw (η)	Lib. III. Cap. I. § 4.
	Untergang Kleiner Hund, mitkulminierend: 3 . Von der Wasserschlange der am Ende des Schwanzes (π).	Downfall Small dog, co-culminating: 3 . From the watersnake at the end of the tail (π).	Lib. III. Cap. n. § 13
	Aufgang der Jungfrau, mitkulminierend: 2. Von der Wasserschlange der nördlichere von denen im Rachen (δ) , 1 Mbr. östlich des Meridians.	Rising of Virgo, co-culminating: 2. of the watersnake the more northerly of those in the throat (δ), 1 moon width east of the meridian.	Lib. III. Cap. III. § 3
	Aufgang des Skorpions, mitkulminierend: Von der Wasserschlange von den vieren nach dem hellsten [vor dem Becher] der dritte von Westen (ν2 Hydrae)	Rising of the scorpion, co-culminating: Of the watersnake of the four after the brightest [before the cup] the third from the west (ν2 Hydrae)	Lib. III. Cap. III. § 5.

The mathematical astronomer mentions this constellation rising and setting.

Greek	German (Manitius 1894)	English (from Manitius 1894)
	Die Wasserschlange (Hydra). Aufgang von Cnc 18 1/2 Grad bis Lib 15 1/2 Grad, Mitkulmination Ari 2 1/2 Grad bis Cnc 18 Grad. Anfang: Der nördlichere von denen im Rachen (δ). Ende: Der am Ende des Schwanzes (π). Ari 2 1/2° Vom Perseus der nebelförmige im Sichelschwert (χh). Der Knoten im Band der Fische (α), 1 Mbr. östlich des Meridians. Der nachfolgende von den drei hellen im Kopfe des Widders (α), 1 Mbr. östlich des Meridians. Cnc 18° Vom Löwen der südlichere der vorangehenden von denen im Kopfe (λ). Von der Argo der nördlichere von denen in der Mitte des Mastes ( o3 Argus = γ Pyxidis Nauticae) Dauer des Aufgangs: 7 1/15 St. = 424m = 106°.	The water snake (Hydra). Rising from Cnc 18 1/2 degrees to Lib 15 1/2 degrees, co-culmination Ari 2 1/2 degrees to Cnc 18 degrees. Beginning: The more northerly of those in the throat (δ). End: The one at the end of the tail (π). Ari 2 1/2° From Perseus the nebulous one in the crescent sword (χh). The node in the band of Pisces (α), 1 moon width east of the meridian. The next of the three bright ones in the head of Aries (α), 1 moon width east of the meridian. Cnc 18° Of Leo the more southerly of the preceding of those in the head (λ). Of the Argo the more northerly of those in the centre of the mast ( o3 Argus = γ Pyxidis Nauticae) Duration of the rise: 7 1/15 hours = 424m = 106°.	Lib III, Cap. I, §1
	Die Wasserschlange (Hydra). Untergang von Gem 29° bis Vir 11°; Mitkulmination Lib 18 1/2 Grad bis Sgr 18 1/2 Grad. Anfang: Der südlichere von denen im Raben (σ). Ende: Der am Ende des Schwanzes (π). Lib 18 1/2 Vom Drachen der drittletzte helle im Schwanze (α), 1 Mbr. westlich des Meridians. Vom Bootes der helle im Gürtel (ε). Von den Scheren der vor dem hellen am Ende der nördlichen Schere vorangehende (δ). Von der Wasserschlange der am Ende des Schwanzes (γ Librae ), 1 Mbr. westlich des Meridians. Sgr 18 1/2 Vom Drachen die südlichere Schläfe (γ). Von der Schlange des Ophiuchos der am Ende des Schwanzes (θ). Vom Schützen der vorangehende von denen im Obergewande (d). Dauer des Untergangs: 4 St. = 240m = 60°.	The watersnake (Hydra). Setting from Gem 29° to Vir 11°; co-culmination Lib 18 1/2 degrees to Sgr 18 1/2 degrees. Beginning: The more southerly of those in the raven (σ). End: The one at the end of the tail (π). Lib 18 1/2 Of the kite the third last light in the tail (α), 1 Mbr. west of the meridian. Of the Bootes the bright one in the belt (ε). Of the scissors, the one preceding the bright one at the end of the northern scissors (δ). Of the water snake the one at the end of the tail (γ Librae ), 1 Mbr. west of the meridian. Sgr 18 1/2 Of the dragon the more southern temple (γ). Of the serpent of Ophiuchus, that at the end of the tail (θ). Of the archer the preceding one of those in the upper garment (d). Duration of the setting: 4 hours = 240m = 60°.	Lib. III. Cap. II. § 1.

Greek	German	English
	Der nördlichere von denen im Rachen (δ).
	Der aro Ende des Schwanzes (π)

• The first star rising is ,
• the last star rising is the one at the tip of the tail (ὁ ἐν ἄκρᾳ τῇ οὐρᾷ).

Dauer des Aufgangs : 7 1/15 St. = 424m = 106°.

Further stars mentioned

Greek (Manitius 1894)	German (Manitius 1894)	English (...)
	Von der Wasserschlange

Hyginus, Astronomica

This is the sign on which the Crow sits and over which the Bowl is placed. The following reason has been handed down: When Apollo was sacrificing, the crow, who was under his guardianship, was sent to a spring to get some pure water. Seeing several trees with their figs not yet ripe, he perched on one of them waiting for them to ripen. After some days when the figs had ripened and the crow had eaten some, Apollo, who was waiting, saw him come flying in haste with the bowl full of water. For this fault of tardiness Apollo, who had had to use other water because of the crow's delay, punished him in this way. As long as the figs are ripening, the crow cannot drink, because on those days he has a sore [?] throat,. So when the god wished to illustrate the thirst of the crow, he put the bowl among the constellations, and placed the water-snake underneath to delay the thirsty crow. For the crow seems to peck at the end of its tail to be allowed to go over to the bowl.

Istros and several others have said that the Crow was Coronis, daughter of Phlegyas. She bore Aesculapius to Apollo, but after Ischys, son of Elatus, had lain with her, the crow, which had noted it, reported it to Apollo. For his unpleasant news Apollo changed him to black instead of his former white color, and transfixed Ischys with his arrows.

About the Bowl Phylarchus writes this tale: In the Chersonnese near Troy where many have said the tomb of Protesilaus is located, there is a city, Elaeusa by name. When a certain Demophon was ruling there, a sudden plague fell on the land with a strange death-rate among the citizens. Demophon, greatly disturbed by this, sent to the oracle of Apollo seeking a remedy, and was told that every year one girl of noble rank should be sacrificed to their household gods. Demophon, passing over his own daughters, would choose by lot one of the daughters of the nobles, and kept doing this until his scheme offended a certain man of highest rank. He said he wouldn't allow his daughter to be entered in the drawing unless the daughters of the king were included. The king, angered by this, killed the noble's daughter without drawing of lots. This deed Mastusius, father of the girl, for a time out of patriotism pretended he did not resent, for the girl might have perished if the lots had been taken. Little by little, time led the king to forget. When the girl's father had shown himself to be on most friendly terms with the king, he said he was going to make a solemn sacrifice and invited the king and his daughters to join the celebration. The king, suspecting nothing, sent his daughters ahead; since he was busy with a state affair, he would come later. When this happened as Mastusius wished, he killed the king's daughters, and mixing their blood with wine in a bowl, bade it be given as a drink to the king on his arrival. The king asked for his daughters, and when he learned what had happened, he ordered Mastusius and the bowl to be thrown into the sea. The cape where he was thrown, to memorialize him is called Mastusian; the harbour still is called the Bowl. Astronomers of old pictured it in the stars, so that men might remember that no one can profit from an evil deed with impunity, nor can hostilities often be forgotten. Some, with Eratosthenes, say that it is the bowl Icarus used when he showed wine to men; others the jar into which Mars was thrown by Otus and Ephialtes. (Mary Ward 1960)

Almagest

Greek (Heiberg 18xx)		English (Toomer 1984)	ident.
τῶν έν τῇ κεφαλῇ ε τῶν ἡγοvμένωv β ὁ vοτιώτερος ἐπὶ τῶv μυκτήρων	1	The 5 stars in the head: the southernmost_of the 2 advance ones, which is on the nostrils	sig  Hya
ὁ βορειότερος αὐτῶν καὶ ἐπάνω τοῦ ὀφθαλμοῦ	2	The 5 stars in the head: the northernmost of these [2], which is above the eye	delta Hya
τῶν ἑπομένων αὐτοῑς β ὁ βόρειος ῶς ἑπὶ τοῦ κρανίου	3	The 5 stars in the head: the northernmost of the 2 to tl1e rear ofthese, which is about on the skull	eps Hya
ὁ vοτιώτερος αύτῶν καὶ ἑπὶ τοῦ χάσματος	4	The 5 stars in the head: the southernmost of them, on the gaping jaws	eta Hya
ὁ πᾶσιv ἑπόμεvος ὡς ἑπὶ τῆς γένvος	5	The 5 stars in the head: the reannost of all, about on the cheek	zet Hya
τῶν ἐv τῇ έκφύσει του τραχήλου β ὁ ἡγούμενος	6	The more advanced ofthe 2 star~ in the place where the neckjoins [the head)	omega Hya
ὁ ἑπόμενος αὐτῶν	7	The rearmost of them	theta Hya
τῶν ἑξης ἐν τῇ καμπῇ τοῦ τραχήλου γ ὁ μέσος	8	The middle star of the following three in the bend of the neck	tau2 Hya
ὁ ἑπόμενος τῶν γ	9	The rearmost of the 3	iota Hya
ὁ νοτιώτατος αὐτῶν	10	The southernmost of them	tau1 Hya
τῶν ἀπο νότου β συνεχῶν δ άμαvρος καὶ βόρειος	11	The faint, northernmost star of the 2 close tagether to the south	BSC 3750
ὁ λαμρὸς τῶν β συνεχῶν	12	The bright one of these two close stars	alpha Hya
τῶν μετὰ τὴν καμπὴν ἑπομέvων γ ὁ ἡγούμενος	13	The most advanced ofthe 3 stars to the rear, afl:er the bend [in the neck	kappa Hya
ὁ μέσος αὐτῶν	14	The middle one	upsilon1 Hya
ὁ έπόμενος τῶν τριῶν	15	The rearmost of the three	upsilon2 Hya
τῶv ἑξῆς ὠς ἐπ' εὐθείας γ ὁ ἡγούμενος	16	The most advanccd of the ncxt 3 stars almost on a straight line	mu Hya
ὁ μέσος αυτῶν	17	The middle one	phi Hya
ὁ έπόμενος τῶv τριῶν	18	The rearmost of the three	nu Hya
τῶν μετὰ τὴν βάσιν τού Κρατῆρος β ὁ βορειότερος	19	The northernmost of the 2 stars aher [i.c.  to the rear o.t]  the base of Crater	beta Crt
ὁ νοτιώτερος αυτῶν	20	The southernmost of thcm	chi1 Hya
τῶv μετα τούτους γ ὡς ἐν τριγώνῳ ὁ ἡγούμενος	21	The most advanced of the 3 stars aller these, as it werc in a triangle	xi Hya
ὁ μέσος αὐτῶν και νοτιώτερος	22	The middle and southernmost onc	omicron Hya
ὁ έπόμενος τῶν τριῶv	23	The rearmost of the three	beta Hya
ὁ μετα τὸν Κόρκα ἐv τῷ παρούρῳ	24	The star after Corvus, in the scction by the tail	gamma Hya
ὁ ἐπ' ἄκρας τῆς οὐρᾶς	25	The star on the tip of the tail	pi Hya
Stars round Hydra outside the constellation:
ὁ ἐκ μεσημβρίας τῆς κεφαλῆς	26	The star to the south of the head	BSC 3314
ὁ ἐκ διαστήματος ἑπόμενος τοῑς ἐν τῷ τραχrjλῳ	27	The star some distance to the rear of those in the neck [ nos. 6-I5]	epsilon Sex

Stars within the Constellation Area

id	Label	IAU design.	description	Vmag
1	Spica	HIP 65474	Inside the hull	0.97
2	Alphard	HIP 46390	Constellation lines	1.97
3	Gienah	HIP 59803	Inside the hull	2.58
4	Kraz	HIP 61359	Inside the hull	2.64
5	Algorab	HIP 60965	Inside the hull	2.94
6	ϵ Corvi	HIP 59316	Inside the hull	2.98
7	γ Hydrae	HIP 64962	Constellation lines	3
8	ζ Hydrae	HIP 43813	Constellation lines (Vertex)	3.1
9	ν Hydrae	HIP 52943	Constellation lines	3.11
10	π Hydrae	HIP 68895	Constellation lines (Vertex)	3.28
11	Ashlesha	HIP 43109	Constellation lines (Vertex)	3.38
12	ξ Hydrae	HIP 56343	Inside the hull	3.54
13	δ Crateris	HIP 55282	Inside the hull	3.56
14	λ Hydrae	HIP 49841	Inside the hull	3.61
15	μ Hydrae	HIP 51069	Constellation lines	3.81
16	θ Hydrae	HIP 45336	Constellation lines	3.91
17	Ukdah	HIP 47431	Inside the hull	3.91
18	Alchiba	HIP 59199	Inside the hull	4.01
19	γ Crateris	HIP 55705	Inside the hull	4.06
20	Alkes	HIP 53740	Inside the hull	4.07
21	Zhang	HIP 48356	Constellation lines	4.11
22	δ Hydrae	HIP 42313	Constellation lines (Vertex)	4.131
23	β Hydrae	HIP 57936	Constellation lines (Vertex)	4.28
24	η Corvi	HIP 61174	Inside the hull	4.294
25	η Hydrae	HIP 42799	Constellation lines	4.3
26	ρ Hydrae	HIP 43234	Inside the hull	4.337
27	Minchir	HIP 42402	Constellation lines (Vertex)	4.43
28	β Crateris	HIP 54682	Inside the hull	4.449
29	τ 2 Hydrae	HIP 46776	Constellation lines	4.548
30	υ 2 Hydrae	HIP 49402	Constellation lines	4.588
31	τ 1 Hydrae	HIP 46509	Constellation lines	4.6
32	Apamvatsa	HIP 66006	Inside the hull	4.69
33	ζ Crateris	HIP 57283	Inside the hull	4.706
34	61 Vir	HIP 64924	Inside the hull	4.74
35	69 Vir	HIP 65639	Inside the hull	4.75
36	ψ Virginis	HIP 62985	Inside the hull	4.8
37	ϵ Crateris	HIP 55687	Inside the hull	4.802
38	U Hya	HIP 52009	Inside the hull	4.82
39	-	HIP 51979	Inside the hull	4.89
40	ϕ 3 Hydrae	HIP 52085	Constellation lines	4.903
41	χ 1 Hydrae	HIP 54204	Inside the hull	4.912
42	ψ Hydrae	HIP 64166	Inside the hull	4.934
43	89 Vir	HIP 67494	Inside the hull	4.959
44	R Hya	HIP 65835	Inside the hull	4.97
45	ω Hydrae	HIP 44659	Constellation lines (Vertex)	4.981
46	82 Vir	HIP 66803	Inside the hull	5.01
47	53 Vir	HIP 64407	Inside the hull	5.04
48	κ Hydrae	HIP 47452	Constellation lines (Vertex)	5.052
49	44 Hya	HIP 51718	Inside the hull	5.06
50	λ Crateris	HIP 55598	Inside the hull	5.09
51	II Hya	HIP 57613	Inside the hull	5.11
52	-	HIP 56332	Inside the hull	5.11
53	-	HIP 60221	Inside the hull	5.139
54	49 Vir	HIP 64078	Inside the hull	5.151
55	90 Vir	HIP 67929	Inside the hull	5.159
56	η Crateris	HIP 58188	Inside the hull	5.16
57	-	HIP 57047	Inside the hull	5.2
58	ζ Corvi	HIP 60189	Inside the hull	5.21
59	76 Vir	HIP 66098	Inside the hull	5.21
60	57 Vir	HIP 64725	Inside the hull	5.22
61	23 Hya	HIP 45527	Inside the hull	5.23
62	ϵ Sextantis	HIP 50414	Inside the hull	5.24
63	-	HIP 53252	Inside the hull	5.24
64	68 Vir	HIP 65581	Inside the hull	5.25
65	31 Crt	HIP 58587	Inside the hull	5.264
66	303 G. Hya	HIP 58082	Inside the hull	5.272
67	200 G. Hya	HIP 49809	Inside the hull	5.296
68	-	HIP 46404	Inside the hull	5.32
69	55 Vir	HIP 64577	Inside the hull	5.33
70	63 Vir	HIP 65301	Inside the hull	5.354
71	328 G. Hya	HIP 61621	Inside the hull	5.41
72	-	HIP 54477	Inside the hull	5.421
73	* gam Sex A	HIP 48437	Inside the hull	5.43
74	87 Vir	HIP 67288	Inside the hull	5.43
75	-	HIP 52737	Inside the hull	5.44
76	330 G. Hya	HIP 62131	Inside the hull	5.454
77	3 Crv	HIP 59394	Inside the hull	5.47
78	ι Crateris	HIP 56802	Inside the hull	5.48
79	-	HIP 54029	Inside the hull	5.511
80	75 Vir	HIP 66091	Inside the hull	5.529
81	33 Hya	HIP 46982	Inside the hull	5.548
82	-	HR 3750	Inside the hull	5.56
83	-	HIP 51046	Inside the hull	5.56
84	g Vir	HIP 64122	Inside the hull	5.564
85	83 Vir	HIP 67057	Inside the hull	5.567
86	* 86 Vir A	HIP 67172	Inside the hull	5.57
87	28 Hya	HIP 46221	Inside the hull	5.579
88	225 G. Hya	HIP 51491	Inside the hull	5.58
89	* 17 Crt A	HIP 56280	Inside the hull	5.58
90	195 G. Hya	HIP 49569	Inside the hull	5.582
91	-	HIP 61296	Inside the hull	5.582
92	18 Sex	HIP 49865	Inside the hull	5.618
93	92 G. Hya	HIP 44356	Inside the hull	5.627
94	-	HIP 61015	Inside the hull	5.63
95	-	HIP 53316	Inside the hull	5.651
96	6 Crv	HIP 60425	Inside the hull	5.658
97	333 G. Hya	HIP 62500	Inside the hull	5.658
98	80 Vir	HIP 66320	Inside the hull	5.706
99	236 G. Hya	HIP 51933	Inside the hull	5.71
100	χ 2 Hydrae	HIP 54255	Inside the hull	5.71
101	-	HIP 61212	Inside the hull	5.726
102	66 Vir	HIP 65420	Inside the hull	5.749
103	351 G. Hya	HIP 66400	Inside the hull	5.78
104	41 Sex	HIP 52980	Inside the hull	5.791
105	357 G. Hya	HIP 67143	Inside the hull	5.795
106	-	HIP 59728	Inside the hull	5.807
107	-	HIP 56078	Inside the hull	5.813
108	-	HIP 61910A	Inside the hull	5.822
109	-	HIP 52948	Inside the hull	5.842
110	-	HIP 61910B	Inside the hull	5.843
111	300 G. Hya	HIP 57841	Inside the hull	5.85
112	-	HIP 53778	Inside the hull	5.857
113	65 Vir	HIP 65323	Inside the hull	5.858
114	329 G. Hya	HIP 61720	Inside the hull	5.866
115	-	HIP 53723	Inside the hull	5.879
116	-	HIP 58158	Inside the hull	5.893
117	17 Sex	HIP 49812	Inside the hull	5.901
118	κ Crateris	HIP 55874	Inside the hull	5.923
119	50 G. Vir	HIP 60595	Inside the hull	5.926
120	y Vir	HIP 66247	Inside the hull	5.932
121	50 Vir	HIP 64224	Inside the hull	5.943
122	25 Sex	HIP 50885	Inside the hull	5.97
123	-	HIP 60157	Inside the hull	5.97
124	92 G. Vir	HIP 62983	Inside the hull	5.975
125	-	HIP 61688	Inside the hull	5.982
126	136 G. Hya	HIP 46288	Inside the hull	5.985
127	73 Vir	HIP 66015	Inside the hull	5.998
128	ϕ 2 Hydrae	HIP 51905	Inside the hull	6.012
129	6 Sex	HIP 48341	Inside the hull	6.016
130	209 G. Hya	HIP 50536	Inside the hull	6.027
131	-	HIP 61951	Inside the hull	6.03
132	227 G. Hya	HIP 51551	Inside the hull	6.03
133	-	HIP 51302	Inside the hull	6.032
134	-	HIP 56364	Inside the hull	6.044
135	243 G. Hya	HIP 52113	Inside the hull	6.045
136	183 G. Vir	HIP 67271	Inside the hull	6.049
137	-	HIP 59895	Inside the hull	6.07
138	-	HIP 50292	Inside the hull	6.075
139	322 G. Hya	HIP 60603	Inside the hull	6.081
140	-	HIP 54214	Inside the hull	6.086
141	-	HIP 49293	Inside the hull	6.097
142	231 G. Hya	HIP 51795	Inside the hull	6.098
143	72 Vir	HIP 65892	Inside the hull	6.098
144	ψ Crateris	HIP 54742	Inside the hull	6.105
145	157 G. Hya	HIP 46869	Inside the hull	6.113
146	155 G. Hya	HIP 46840	Inside the hull	6.12
147	-	HIP 57732	Inside the hull	6.122
148	153 G. Hya	HIP 46744	Inside the hull	6.123
149	154 G. Hya	HIP 46768	Inside the hull	6.124
150	146 G. Hya	HIP 46529	Inside the hull	6.126
151	10 Hya	HIP 42931	Inside the hull	6.127
152	217 G. Hya	HIP 50790	Inside the hull	6.13
153	81 G. Hya	HIP 43902	Inside the hull	6.131
154	105 G. Hya	HIP 45167	Inside the hull	6.131
155	MO Hya	HIP 62788	Inside the hull	6.141
156	-	HIP 56293	Inside the hull	6.16
157	NS Hya	HIP 44738	Inside the hull	6.17
158	-	HIP 63109	Inside the hull	6.174
159	85 Vir	HIP 67139	Inside the hull	6.179
160	TU Crv	HIP 61496	Inside the hull	6.184
161	LV Hya	HIP 58272	Inside the hull	6.189
162	VX Crt	HIP 56899	Inside the hull	6.19
163	-	HIP 56901	Inside the hull	6.198
164	-	HIP 51490	Inside the hull	6.2
165	-	HIP 57079	Inside the hull	6.2
166	-	HIP 53963	Inside the hull	6.202
167	356 G. Hya	HIP 67071	Inside the hull	6.205
168	205 G. Hya	HIP 50066	Inside the hull	6.21
169	135 G. Vir	HIP 65183	Inside the hull	6.21
170	-	HIP 49900	Inside the hull	6.225
171	245 G. Hya	HIP 52391	Inside the hull	6.228
172	-	HIP 56245	Inside the hull	6.228
173	199 G. Hya	HIP 49802	Inside the hull	6.23
174	197 G. Hya	HIP 49689	Inside the hull	6.244
175	159 G. Hya	HIP 46893	Inside the hull	6.25
176	-	HIP 61270	Inside the hull	6.254
177	-	HIP 58574	Inside the hull	6.255
178	147 G. Hya	HIP 46543	Inside the hull	6.257
179	144 G. Hya	HIP 46504	Inside the hull	6.27
180	185 G. Hya	HIP 48763	Inside the hull	6.28
181	-	HIP 60809	Inside the hull	6.294
182	-	HR 4935	Inside the hull	6.3
183	337 G. Hya	HIP 63243	Inside the hull	6.303
184	-	HIP 50584	Inside the hull	6.308
185	37 Hya	HIP 47427	Inside the hull	6.32
186	-	HR 4935	Inside the hull	6.32
187	112 G. Vir	HIP 64181	Inside the hull	6.32
188	-	HIP 48413	Inside the hull	6.329
189	-	HIP 53259	Inside the hull	6.34
190	98 G. Vir	HIP 63220	Inside the hull	6.34
191	-	HIP 54048	Inside the hull	6.343
192	210 G. Vir	HIP 68763	Inside the hull	6.344
193	71 G. Hya	HIP 43570	Inside the hull	6.35
194	172 G. Hya	HIP 47454	Inside the hull	6.356
195	-	HIP 53849	Inside the hull	6.36
196	-	HIP 50552	Inside the hull	6.361
197	50 G. Hya	HIP 42854	Inside the hull	6.362
198	-	HIP 54749	Inside the hull	6.378
199	211 G. Vir	HIP 68739	Inside the hull	6.387
200	34 Hya	HIP 47249	Inside the hull	6.39
201	-	HIP 61208	Inside the hull	6.39
202	204 G. Vir	HIP 68380	Inside the hull	6.394
203	332 G. Hya	HIP 62448	Inside the hull	6.405
204	308 G. Hya	HIP 58436	Inside the hull	6.416
205	-	HIP 48351	Inside the hull	6.42
206	-	HIP 50893	Inside the hull	6.42
207	-	HIP 56830	Inside the hull	6.42
208	320 G. Hya	HIP 60468	Inside the hull	6.42
209	364 G. Hya	HIP 68224	Inside the hull	6.42
210	54 G. Hya	HIP 42981	Inside the hull	6.43
211	274 G. Hya	HIP 54703	Inside the hull	6.43
212	294 G. Hya	HIP 57001	Inside the hull	6.44
213	258 G. Hya	HIP 53387	Inside the hull	6.444
214	270 G. Hya	HIP 54430	Inside the hull	6.453
215	166 G. Hya	HIP 47242	Inside the hull	6.46
216	-	HIP 48839	Inside the hull	6.46
217	88 G. Vir	HIP 62743	Inside the hull	6.471
218	299 G. Hya	HIP 57749	Inside the hull	6.477
219	348 G. Hya	HIP 65969	Inside the hull	6.478
220	233 G. Hya	HIP 51852	Inside the hull	6.479
221	297 G. Hya	HIP 57507	Inside the hull	6.48
222	-	HIP 59742	Inside the hull	6.49
223	346 G. Hya	HIP 65682	Inside the hull	6.49
224	-	HR 4758	Inside the hull	6.49
225	141 G. Vir	HIP 65381	Inside the hull	6.49
226	TT Crv	HIP 60421	Inside the hull	6.494
227	-	HIP 67004	Inside the hull	6.498
228	-	HIP 50693	Inside the hull	6.499
229	-	HIP 51656	Inside the hull	6.5
230	342 G. Hya	HIP 64375	Inside the hull	6.5

Transfer and Transformation of the Constellation

• 
  the Babylonian version of the "Hydra and Corvus" super-constellation does not contain a cup or jar. visualized in Stellarium (drawing by Jessica Gullberg)
• 
  the lonely star in front of the dragon-head (Procyon) rised simultaneously with the faint stars of The Crab in ancient Babylon. Procyon and the head / foot of the dragon may serve as a replacement for Cancer
• 
  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).
• 
  The Greeks introduced a Crater atop the snake. On the Farnese Globe, the body of the snake forms a vessel for Corvus and Crater.
• 
  Hydra with Crater and Corvus on the Mercator Globe (1551)
• 
  In early modern time, some scholars extended the snake-body of Hydra beyond pi Hydrae and placed a second bird (Solitaire or Noctua) at this new end.

Arabic

Hydra in Laffitte (2025, 365). Fig. 77 : Ὕδρη / Hydrē, « l’Hydre », et Κρατήρ / Kratēr, « la Coupe »,

– al-Šuğā^c, « le Gros Serpent », et al-Bāṭiyya, « la Petite Jarre » (ap. Urania’s Mirror)

Dhanab al Shuja (γ Hya : 2,99) / ذنب الشجع

Recently introduced, this name is the Arabic Ḏanab al-Šuğā^c, ‘the Tail of the Hydra’, in an Arabic or Persian catalogue using Greek formatting and as yet unidentified. NB : We have fī aṣal al-ḏanab, ‘at the root of the tail,’ and ^cand al-ḏanab, ‘at the tail,’ π/ γ Hya, and ^calā ṭaraf al-ḏanab, ‘at the tip of the tail,’ π/ γ Hya, c/ the translators of Ptolemy, then al-Ṣūfī and al-Battānī, but Ṭarf al-ḏanab, ‘the tip of the tail’, c/ al-Bīrūnī. However, this name does not appear in any known text. Abs. c/ Allen. Dhanab al-Shuja, Pultar, Dhanab al-Shuja and Cauda Hydrae.

Mythology

Greek/ Greco-Roman folklore

Eratosthenes recounts that the raven was sent by the gods to fetch water for a sacrifice. As long as there was no wine, spring water was considered the most sacred drink. However, on its way, the raven saw a fig tree with green fruit, waited there until they ripened, and ate its fill of the delicious figs. In order to have an excuse for the delay to the gods, he grabbed the water snake in the spring, carried it together with the crater to the gods, and claimed that it had drunk the water he had been sent to fetch.

Apollo, a god of light, divination, and truth, saw through the deception. He punished the raven by condemning it to live among humans and suffer from thirst for a similar length of time. He also placed the image of the raven in the sky, together with the crater and the water snake, as a warning against deception and slander.

While the water snake is innocent in Eratosthenes' version, according to another legend, the Hydra is the monster that was fought and defeated by Heracles. The story is part of the Hercules myth, but the constellation Hercules is far away from the Hydra and has nothing to do with either the raven or the crater. This seems to be a later ancient (Roman?) reinterpretation, because Eratosthenes' version does not seem particularly convincing when looking at the sky.

IAU WGSN

The star pi Hydrae is very important in history as it is one of the keywitnesses for transfer from Hipparchus to Ptolemy.

• name in Hipparchus: ὁ ἐν ἄκρᾳ τῇ οὐρᾷ (the one at the farthest point of the tail)
• name in the Almagest: ὁ ἐπ᾽ἄκρας τῆς οὐρᾶς (the one at the end of the tail)

The Greek term ἄκρᾳ can be translated as "at the farthest point" or "at the end" (or "hightest" which doesn't apply here).

References

• References (general)
• References (Babylonian)
• References (ancient Greco-Roman)
• References (medieval)