Cepheus

Authors: Susanne M Hoffmann, Youla Azkarrula, Doris Vickers

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Cep star chart (IAU and Sky & Telescope magazine, Roger Sinnott & Rick Fienberg)

Cepheus, The King, one of the 88 IAU constellations.

Etymology and History

Origin of Constellation

In Greek mythology, Cepheus is the father of Andromeda and husband of Queen Cassiopeia. Aratos describes him as a lord with outstretched arms, as depicted on the Farnese Globe. Eratosthenes adds that his feet are pointing towards the pole and he is lying up to his chest in the Arctic Circle. His shoulders and head lie between the Arctic Circle and the circle of the summer solstice. This is important for Eratosthenes, as his original text systematically describes the sky from the North Pole southwards: only the Ursa Major, Draco and Cepheus' feet lie within the polar cap, with the heads of Draco and Cepheus lying outside this ever-visible circle – at least when viewed from Alexandria in Egypt. In Athens, the dragon's head would still be fully within the Arctic Circle and only the head of Cepheus would protrude beyond it.

This information suggests a more northerly geographical latitude and could therefore indicate that this figure (group of figures) originated in what is now Greece. At least Eratosthenes' source seems to come from there – although it is impossible to make any definitive statements about transfers many centuries ago.

What is clear is that this figure does not originate from Mesopotamia, because at least the area outside the Arctic Circle, i.e. the head and shoulders of Cepheus, belonged in Mesopotamia to the figure of a giant demon with an open mouth. We describe this constellation of the demon in Cygnus, the Swan.

Babylonian

see

• UD.KA.DU₈.A (𒌓𒅗𒂃𒀀)

Kugel Globe (1st c.BCE): Andromeda, Cassiopeia, Perseus, Cepheus, drawing by SMH 2024.

Greco-Roman

Aratos

Nor will the suffering family of Cepheus, son of Iasius, [180] be just left unmentioned: their name also has reached the sky, for they were akin to Zeus. Behind the Bear Cynosura [Ursa Minor] Cepheus himself is like a man stretching out both his arms. The line that extends from the tip of her tail to each of his feet equals the distance from foot to foot. [186] And you have only to look a little way past his belt if you are searching for the first coil o f the great Dragon.

(Kidd 1997)

Hipparchus

Rising (Lib II Cap V §10)

The Rising of ...

	east		south
	lam1	lam2	lam1	lam2
	Sco 26 1/2	Sgr 5 1/2	Vir 8 1/2	Vir 21
star	the one who preceds the three in the head (mu)	the southern one of those in the head (eps)
duration	3/4 hours = 45 min = 11 1/4 degree

Setting (Lib II Cap VI §10)

	west		south
	lam1	lam2	lam1	lam2
	Ari 7 1/2	Ari 14	Cnc 9	Cnc 14
star	the southern one of those in the head (eps)	the northern one of those [in the head]
duration	1/3 hours = 20 min = 5°

Stars Mentioned

	Greek	German	English	ident.	src		lam_culm
					Lib II Cap V §10	rising, east, first
					Lib II Cap V §10	rising, east, last
					Lib II Cap VI §2	setting CrB, south, last	Psc 13.5
					Lib II Cap VI §13	setting Aql, south, first	Ari 2
					Lib III Cap I §9	rising Ori, south, last	Psc 13

Hyginus, Astronomica

Euripides and the rest have shown that he was the son of Phoenix, king of the Ethiopians, and father of Andromeda, the girl exposed to the sea-monster, according to the well-known tale. Perseus freed her from danger and made her his wife. And so, that the whole family be commemorated, the gods numbered Cepheus, too, among the constellations. (Mary Ward 1960)

Almagest Κηφεύς

id	Greek (Heiberg 1898)	English (Toomer 1984)	ident.
	Κηφέως ἀστερισμός.	Constellation of Cepheus
1	ὁ ἐπὶ τοῦ δεξιοῦ ποδός	The star on the right leg	kap Cep
2	ἐπὶ τοῦ ἀριστεροῦ ποδός	The one on the left leg	gam Cep
3	ὁ ὑπὸ τὴν ῥώνηη ἐπὶ τοῦ δεξιοῦ πλευροῦ	The star under the belt on the right side	bet Cep
4	ὁ ὑπὲρ τὸν δεξιὸν ὤμου ἀπτόμευος.	The star·over the tight shoulder, which touches it	alf Cep
5	ὁ ὑπὲρ τὸν δεξιὸυ ἀγκῶνα ἀπτόμερος	The star over the right elbow, which touches it	eta Cep
6	ὁ ὑπὸ τὸν αὐτὸν ἀγκῶνα καὶ αὐτὸς ἀπτόμενος.	The one under that elbow, which also touches it	tet Cep
	ὁ ἐν τῷ στήθει	The star in the chest	xi Cep
	ὁ ἐπὶ τοῦ ἀριστεροῦ βραχύουος	The star on the left arm	iot Cep
	τῶν ἐπὶ τῆς τιάρας 7’ ὁ νότιος.	The southernmost of the 3 stars on the tiara	eps Cep
	ὁ μέσος τῶν τριῶν.	The middle one of the three	zet Cep
	ὁ βορειότερος τῶν τριῶν.	The northernmost of the three	lam Cep
	ἀστέρες ιἄ, ὥν γ’ μεγέθους ἄ, δ’ ξ,εη.	11 stars, l of the third magnitude, 7 of the fourth, 3 of the fifth
	Τῶν περὶ Κηφέα ἀμορφώτων.	Stars around Cepheus outside the constellation
	ὁ προηγούμενος τῆς τιάρας.	The one in advance of the tiara	mu Cep
	ὁ ἐπόμενος τῇ τιάρα	The one to the rear or the tiara	del Cep
	ἀμόρφωτοι β, ὧν δ’ μεγέθους ἄ, ε α	2 stars outside the constellation, 1 of the fourth magnitude, 1 of the fifth

Convex Hull for the stars inside Kepheus (CC BY Youla Azkarrula).

Stars within the Constellation Area

id	Label	IAU design.	description	Vmag
1	Alderamin	HIP 105199	Constellation lines	2.46
2	Errai	HIP 116727	Constellation lines (Vertex)	3.21
3	Alfirk	HIP 106032	Constellation lines	3.23
4	ζ Cephei	HIP 109492	Constellation lines	3.35
5	η Cephei	HIP 102422	Constellation lines (Vertex)	3.41
6	ι Cephei	HIP 112724	Constellation lines (Vertex)	3.54
7	Garnet Star	HIP 107259	Inside the hull	4.08
8	ϵ Cephei	HIP 109857	Constellation lines (Vertex)	4.18
9	θ Cephei	HIP 101093	Constellation lines (Vertex)	4.22
10	Kurhah	HIP 108917	Constellation lines	4.29
11	ν Cephei	HIP 107418	Inside the hull	4.29
12	κ Cephei	HIP 99255	Constellation lines (Vertex)	4.4
13	9 Cep	HIP 106801	Inside the hull	4.73
14	24 Cep	HIP 109400	Inside the hull	4.786
15	VV Cep	HIP 108317	Inside the hull	4.9
16	-	HIP 108535	Inside the hull	5.01
17	λ Cephei	HIP 109556	Constellation lines	5.05
18	-	HIP 111532	Inside the hull	5.05
19	19 Cep	HIP 109017	Inside the hull	5.11
20	78 Dra	HIP 107230	Inside the hull	5.173
21	6 Cep	HIP 105268	Inside the hull	5.18
22	AF Dra	HIP 101260	Inside the hull	5.185
23	30 Cep	HIP 111797	Inside the hull	5.188
24	20 Cep	HIP 109005	Inside the hull	5.265
25	18 Cep	HIP 108924	Inside the hull	5.3
26	-	HIP 109592	Inside the hull	5.359
27	7 Cep	HIP 105972	Inside the hull	5.41
28	-	HIP 110725	Inside the hull	5.469
29	12 Cep	HIP 107586	Inside the hull	5.514
30	26 Cep	HIP 110817	Inside the hull	5.515
31	-	HIP 109474	Inside the hull	5.52
32	-	HIP 106227	Inside the hull	5.522
33	14 Cep	HIP 108772	Inside the hull	5.542
34	4 Cep	HIP 102253	Inside the hull	5.6
35	-	HIP 111242	Inside the hull	5.7
36	25 Cep	HIP 110103	Inside the hull	5.741
37	-	HIP 111660	Inside the hull	5.777
38	-	HIP 109620	Inside the hull	5.778
39	-	HIP 108226	Inside the hull	5.86
40	-	HIP 104171	Inside the hull	5.877
41	-	HIP 104968	Inside the hull	5.898
42	-	HIP 107374	Inside the hull	5.94
43	-	HIP 108505	Inside the hull	5.979
44	-	HIP 103219	Inside the hull	5.988
45	-	HR 8375	Inside the hull	6.01
46	-	HIP 110498	Inside the hull	6.032
47	-	HIP 109659	Inside the hull	6.082
48	-	HIP 107197	Inside the hull	6.088
49	NGC 7160	NGC 7160	Inside the hull	6.1
50	-	HIP 105370	Inside the hull	6.104
51	-	HIP 109746	Inside the hull	6.121
52	-	HIP 108209	Inside the hull	6.125
53	V426 Cep	HIP 105949	Inside the hull	6.129
54	-	HIP 107723	Inside the hull	6.17
55	-	HIP 101134	Inside the hull	6.221
56	-	HR 8595	Inside the hull	6.24
57	-	HIP 110919	Inside the hull	6.285
58	-	HIP 109585	Inside the hull	6.3
59	-	HIP 111325	Inside the hull	6.32
60	-	HIP 108420	Inside the hull	6.34
61	-	HIP 109190	Inside the hull	6.341
62	80 Dra	HIP 109434	Inside the hull	6.346
63	-	HIP 107893	Inside the hull	6.38
64	-	HIP 104788	Inside the hull	6.39
65	-	HIP 108364	Inside the hull	6.394
66	-	HIP 111314	Inside the hull	6.44
67	V431 Cep	HIP 106604	Inside the hull	6.45
68	-	HIP 107555	Inside the hull	6.45
69	-	HIP 102771	Inside the hull	6.451
70	-	HIP 102370	Inside the hull	6.48
71	-	HIP 107710	Inside the hull	6.48
72	V422 Cep	HIP 105193	Inside the hull	6.49

Mythology

Eratosthenes says that it was Athena's wish to place Cepheus and Andromeda in the heavens. He was her father and, according to Euripides, the king of Ethiopia. As he was responsible for his country, he is said to have reluctantly thrown his daughter to the sea monster to be devoured. However, she was saved by Perseus. The location of Aithiopia for the Greeks is disputed in research and may have varied over the centuries or for different poets. The name Aithiopians only indicates that they were dark-skinned – it could therefore refer to many places between India and North Africa.

References

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