COSMOS / CONSTELLATIONS / LIB
Libra (Scales)
The Scales. IAU abbreviation Lib. One of the 48 classical constellations listed by Ptolemy in the Almagest in the 2nd century AD.
STAR CHART
KEY FACTS
- IAU abbreviation
- Lib
- Latin name / genitive
- Libra / Librae
- Position
- Right ascension ≈ 15 h 17 m; declination −30° to −1°
- Visibility from Türkiye
- Visible in full from anywhere in Türkiye. When it crosses the meridian its centre stands about 35° above the horizon from Ankara.
- Best time to observe
- Best placed at 21:00 Türkiye time around 8 July.
- Number of stars
- 88 stars brighter than magnitude 6.5 in the catalogue; 16 brighter than 5 and 6 brighter than 4.
INTERACTIVE LAB
Where is Libra tonight?
The lab opens for Ankara on today’s date. Drag the time slider through the night; the “Best night” button jumps to the date when the constellation is highest at 21:00 (around 8 July). Change the city to compare the view from elsewhere in Türkiye and around the world.
MYTH, HISTORY AND OBSERVING
The only zodiac constellation that represents an object rather than a living being: the scales of justice. In ancient Greece it was counted as the claws of Scorpius; the names Zubenelgenubi and Zubeneschamali mean “southern claw” and “northern claw” in Arabic. Some observers see a faint greenish tint in Zubeneschamali.
BRIGHTEST STARS
| Star | Magnitude | Distance (light-years) | Spectral type |
|---|---|---|---|
| Zubeneschamali | 2.61 | 185 | B8V |
| Zubenelgenubi | 2.75 | 76 | A3IV |
| Brachium | 3.25 | 288 | M3/M4III |
| υ Lib | 3.60 | 224 | K3III |
| τ Lib | 3.66 | 367 | B2.5V |
| Zubenelhakrabi | 3.91 | 163 | K0III |
| θ Lib | 4.13 | 168 | K0III |
| 16 Lib | 4.47 | 88 | F0V |
Magnitude: apparent brightness; the smaller the number, the brighter the star. Distances derive from parallax measurements and are uncertain for distant stars. Source: HYG v4.1 star catalogue (CC BY-SA 4.0).
SOURCES
Position, visibility and best observing time were computed approximately for this page from the catalogue stars (Ankara, 39.9° N). The 88 constellations were adopted by the IAU in 1922; their boundaries were drawn by Eugène Delporte in 1930.