Libra

Authors: Susanne M Hoffmann, Youla Azkarrula

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star chart

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

One of the 88 IAU constellations.

Etymology and History

The Greek constellation ...

Origin of Constellation

Greco-Roman

Hipparchus

Rising (Lib II Cap V §10)

The Rising of ...

	east		south
	lam1	lam2	lam1	lam2
star
duration	2 1/8 hours = 127.5 min = 31 7/8 degree

Setting (Lib II Cap VI §10)

	west		south
	lam1	lam2	lam1	lam2
star
duration	2 2/3 hours = 160 min = 40°

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

Almagest Χηλαί.

id	Greek (Heiberg 1898)	English (Toomer 1984)	ident.
	Χηλῶν ἀστερισμός.	Constellation of The Claws
1	τῶν ἐπ’ ἄκρας τῆς νοτίου χηλῆς ὁ λαμπρός	Stars on the tip of the southern claw: the bright one	alf Lib
2	ὁ βορειότερος αὐτοῦ καὶ ἀμαυρότερος;	Stars on the tip of the southern claw: the star to the north of this and fainter than it	mu Lib
3	τῶν ἐπ’ ἄκρας τῆς βορείου χηλῆς ὁ λαμπρός	Stars an the tip of the northern claw: the bright one	bet Lib
4	ὁ προηγούμενος αὐτοῦ καὶ ἀμαυρός.	Stars an the tip of the northern claw: the faint star in a,dvance of this	del Lib
5	ὁ ἐν μέσῃ τῇ νοτόῳ χηλῇ	The star in the middle of the southern claw	iot Lib
6	ὁ τούτου προηγούμενος ἐπὶ τῆς αὐτῆς χηλῆς	The one in advance of this an the same claw	nu Lib
7	ὁ ἐν μέσῃ τῇ βορεύῳ χηλῇ.	The star in the middle of the northern claw	gam Lib
9	ὁ ἑπόμενος αὐτῷ ἐπὶ τῆς αὐτῆς χηλῆς	The one to the rear of this on the same daw	tet Lib
	ἀστέρερ ἡ, ὥν β’ μεγέθους β, δ’ ὅ, ε’ β.	{8 stars, 2 of the second magnitude, 4 of the fourth, 2 of tl;le fifth}
	Οἱ περὶ τὰς χηλὰς ἀμόρφωτοι	Stars araund Libra outside the constellation
10	τῶν βορειοτέρων τῆς βορείου χηλῆς β' ὁ προηγούμενος	The most advanced of the 3 stars north of the northern claw	37 Lib
11	τῶν ἐπομένων β ὁ νοτιώτερος	The southernmost of the rearmost 2 [ of these]	48 Lib
12	ὁ βόρειος αὐτῶν	The northernmost of them	xi Lib
13	τῶν μεταξὺ τῶν χηλῶν » ὁ ἐπόμευος	The rearmost of the 3 stars between the claws	lam Lib
14	τῶν λοιπῶν β καὶ προηγουμένων ὁ βόρειος.	The northernmost of the other 2 in advance f of the lauer 1	41 Lib
15	ὁ νότιος αὐτῶν	The southernmost of them	HR 5810
16	τῶν νοτιωτέρου τῆς νοτίου χηλῆς 7 ὁ προηγούμενος.	The most advanced of the 3 stars south of the southern claw	20 Lib
17	τῶν λοιπῶν καὶ ἐπομένωυ β ὁ βορειότερος.	The northernmost of the other, rear 2	39 Lib
18	ὁ νοτιώτερος αὐτῶν	The southernmost of them	40 Lib
	ἀστέρες 9, ὧν γ’ μεγέθουρ ἄ, δ’ ἓ, ε β, ς ἂ.	9 stars, I of the third magnitude, 5 of the fourth, 2 of the fifth, 1 of the sixth

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

Stars within the Constellation Area

id	Label	IAU design.	description	Vmag
1	Zubeneschamali	HIP 74785	Constellation lines (Vertex)	2.62
2	Zubenelgenubi	HIP 72622	Constellation lines (Vertex)	2.75
3	Zubenelhakrabi	HIP 76333	Constellation lines	3.91
4	θ Librae	HIP 77853	Constellation lines (Vertex)	4.16
5	ι 1 Librae	HIP 74392	Constellation lines (Vertex)	4.54
6	δ Librae	HIP 73473	Constellation lines (Vertex)	4.93
7	ν Librae	HIP 73945	Constellation lines	5.2
8	μ Librae	HIP 72489	Constellation lines (Vertex)	5.31
9	η Librae	HIP 77060	Inside the hull	5.412
10	ξ 2 Librae	HIP 73133	Inside the hull	5.45
11	ζ 4 Librae	HIP 76126	Inside the hull	5.499
12	ζ 1 Librae	HIP 75730	Inside the hull	5.626
13	-	HIP 75352	Inside the hull	5.716
14	ξ 1 Librae	HIP 72934	Inside the hull	5.788
15	ζ 3 Librae	HIP 75944	Inside the hull	5.806
16	18 Lib	HIP 73310	Inside the hull	5.857
17	ι 2 Librae	HIP 74493	Inside the hull	6.066
18	ο Librae	HIP 75118	Inside the hull	6.143
19	28 Lib	HIP 75110	Inside the hull	6.17
20	26 Lib	HIP 74600	Inside the hull	6.172
21	-	HIP 77007	Inside the hull	6.295
22	22 Lib	HIP 73953	Inside the hull	6.404
23	30 Lib	HIP 75294	Inside the hull	6.48
24	-	HIP 74391	Inside the hull	6.49

Transfer and Transformation of the Constellation

• 
  Libra (two versions) in as-Sufi, Kitāb Ṣuwar al-kawākib al-thābitah, Mosul 1170, Bodleian Libraries, University of Oxford,
• Libra in Bayer (1603).
  Libra in Bayer (1603).
• Libra in Flamsteed (1776)
  Libra in Flamsteed (1776)
• Libra in Bode (1782,1805)
  Libra in Bode (1782,1805)
• Libra in Jamieson (1822)
  Libra in Jamieson (1822)
• Libra zodiac sign, Jantar Mantar, Jaipur, India
  Libra zodiac sign, Jantar Mantar, Jaipur, India

References

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