Constellation, Her
Hercules: the Hercules
Hercules covers 1,225 square degrees of sky, the 5th largest of the 88. Its brightest star is Kornephoros. It is best placed in the evening sky in July.
Hercules at a glance
| Fact | Value |
|---|---|
| IAU abbreviation | Her |
| Meaning | the Hercules |
| Pronounced | HER-kyuh-leez |
| Genitive, used in star names | Herculis (for example a Bayer name such as α Herculis) |
| Area | 1,225 square degrees, number 5 of 88 by size |
| Stars to magnitude 6 in our catalogue | 135 |
| Brightest star | Kornephoros, magnitude 2.8 |
| Best seen | Evenings in July, when it is highest at 9 pm |
| Declination range | 4° to 51° |
| Borders | Ophiuchus, Lyra, Serpens, Draco, Corona Borealis, Boötes, Aquila, Vulpecula, Sagitta |
Where on Earth you can see Hercules
Hercules spans declinations 4° to 51°. Every part of it rises above the horizon at some moment for observers between latitudes 39°S and 90°N. Some of it can be seen from latitudes 86°S to 90°N. North of 86°N 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 | 80° |
| New York | 40.7°N | All of it rises | 77° |
| London | 51.5°N | All of it rises | 67° |
| Tromsø | 69.6°N | All of it rises | 48° |
| Tokyo | 35.7°N | All of it rises | 82° |
| Sydney | 33.9°S | All of it rises | 28° |
Hercules's named stars
These stars in Hercules have names approved by the IAU Working Group on Star Names. Magnitude is brightness: a lower number is brighter, and the faintest stars seen with the naked eye on a dark night are about magnitude 6.
| Star | Designation | Magnitude | Distance (light-years) |
|---|---|---|---|
| Kornephoros | β Herculis | 2.78 | 140 |
| Rasalgethi | α1 Herculis | 2.78 | 360 |
| Sarin | δ Herculis | 3.12 | 75.1 |
| Maasym | λ Herculis | 4.41 | 370 |
| Cujam | ω Herculis | 4.57 | 250 |
| Marsic | κ Herculis | 5.00 | 370 |
Distances are about, from the HYG database (Hipparcos parallax), and "not known" means the catalogue has no reliable parallax for that star.
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 Hercules'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