COSMOS / CONSTELLATIONS / HOR
Horologium (Pendulum Clock)
The Pendulum Clock. IAU abbreviation Hor. One of the 14 southern constellations that Nicolas-Louis de Lacaille introduced after observing from the Cape of Good Hope in 1751–1752.
STAR CHART
KEY FACTS
- IAU abbreviation
- Hor
- Latin name / genitive
- Horologium / Horologii
- Position
- Right ascension ≈ 3 h 10 m; declination −67° to −40°
- Visibility from Türkiye
- From Türkiye only its northern part is seen, low on the southern horizon; the southern provinces are better placed.
- Best time to observe
- Best placed at 21:00 Türkiye time around 5 January.
- Number of stars
- 32 stars brighter than magnitude 6.5 in the catalogue; 3 brighter than 5 and 1 brighter than 4.
INTERACTIVE LAB
Where is Horologium tonight?
Only the northern part of this constellation is seen from Türkiye, low on the southern horizon. The lab opens for Ankara on today’s date; switch the city to Antalya and then to Sydney and watch how the “Visible part” row and the chart change. The “Best night” button jumps to the best date (around 5 January).
MYTH, HISTORY AND OBSERVING
A faint constellation near the southern end of Eridanus, dedicated by Lacaille in 1756 to the pendulum clock. Most of it is not visible from Türkiye; only its northern tip rises just above the southern horizon.
BRIGHTEST STARS
| Star | Magnitude | Distance (light-years) | Spectral type |
|---|---|---|---|
| α Hor | 3.85 | 115 | K1III |
| δ Hor | 4.93 | 179 | A9V |
| β Hor | 4.98 | 295 | A5III |
| μ Hor | 5.12 | 142 | F0IV |
| ζ Hor | 5.21 | 160 | F4IV |
| ν Hor | 5.25 | 165 | A2V |
| η Hor | 5.30 | 149 | A6V |
| HIP 20161 | 5.33 | 252 | K2III |
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.