Constellation, Hor
Horologium: the Clock
Horologium covers 250 square degrees of sky, the 58th largest of the 88. Its brightest star is star HIP 19747. It is best placed in the evening sky in December.
Show Horologium in the live sky
Horologium at a glance
| Fact | Value |
|---|---|
| IAU abbreviation | Hor |
| Meaning | the Clock |
| Pronounced | hor-uh-LOE-jee-um |
| Genitive, used in star names | Horologii (for example a Bayer name such as α Horologii) |
| Area | 250 square degrees, number 58 of 88 by size |
| Stars to magnitude 6 in our catalogue | 18 |
| Brightest star | star HIP 19747, magnitude 3.9 |
| Best seen | Evenings in December, when it is highest at 9 pm |
| Declination range | -67° to -40° |
| Borders | Eridanus, Reticulum, Hydrus, Dorado, Caelum |
Where on Earth you can see Horologium
Horologium spans declinations -67° to -40°. Every part of it rises above the horizon at some moment for observers between latitudes 90°S and 23°N. Some of it can be seen from latitudes 90°S to 50°N. South of 50°S none of it ever sets. This is geometry only: it ignores haze, hills and buildings near the horizon.
From six cities
| City | Latitude | Visibility | Middle at its highest |
|---|---|---|---|
| Pune | 18.5°N | All of it rises | 18° |
| New York | 40.7°N | Only part of it rises | below the horizon |
| London | 51.5°N | Never rises | below the horizon |
| Tromsø | 69.6°N | Never rises | below the horizon |
| Tokyo | 35.7°N | Only part of it rises | 0° |
| Sydney | 33.9°S | All of it rises | 70° |
Horologium's named stars
None of the stars brighter than magnitude 6 in Horologium has a name approved by the IAU Working Group on Star Names.
How these facts were found
The name, meaning and boundaries are the IAU's. Area, borders and the latitude ranges are computed from those boundaries; the brightest star and the star count come from a magnitude-6 star catalogue; star names are matched to the catalogue by Hipparcos number and checked by position. The month is when Horologium's middle crosses the north-south line of the sky at 9 pm local solar time. See How we know.
Sources
- IAU: The Constellations. Names, meanings, pronunciations and boundaries
- IAU Working Group on Star Names. The official names of stars
- astronomy-engine. The MIT licensed library that does the calculations, run on the page's build machine and in the app
- HYG database v4.4 (astronexus). Distances, spectral types and luminosities, licence CC BY-SA 4.0