What kind of star is Kornephoros?
Kornephoros, catalogued as Beta Herculis (β Her; name applies to component Aa), appears in the official constellation Hercules. Its apparent visual magnitude is 2.77, while its estimated distance is about 148 light-years. Astronomers classify the object as G7 IIIa; spectroscopic binary. These labels describe temperature, luminosity class or system components; they should not be read as a claim that every naked-eye point is a single isolated star.
Beta Herculis is an evolved G-type giant roughly 148 light-years away. It is a single-lined spectroscopic binary: the visible giant's absorption lines shift with an orbit of about 410 days, while its fainter companion contributes little detectable light. The giant has expanded and cooled after leaving the main sequence and is more luminous than the Sun despite a broadly yellow colour. Its atmosphere shows a mild iron deficiency in SIMBAD's detailed spectral notation. Unlike a wide visual double, this system cannot be confirmed merely by increasing eyepiece magnification; spectroscopy measures motion along the line of sight. Kornephoros is therefore a useful bridge between an accessible naked-eye landmark and the less intuitive evidence astronomers use to discover unseen stars.
The coordinate pair RA 16h 30m 13.20s, Dec +21° 29′ 22.6″ fixes the object's direction on the celestial sphere for the J2000 reference epoch. Right ascension works like celestial longitude measured in hours, while declination works like latitude north or south of the celestial equator. Proper motion and improved measurements can refine catalogue positions, but these coordinates are sufficiently precise for a finder chart or planetarium search.
Kornephoros data at a glance
| Proper name | Kornephoros | Catalogue designation | Beta Herculis (β Her; name applies to component Aa) |
|---|---|---|---|
| Constellation | Hercules | Apparent magnitude | 2.77 |
| Spectral or system type | G7 IIIa; spectroscopic binary | Estimated distance | about 148 light-years |
| Right ascension (J2000) | 16h 30m 13.20s | Declination (J2000) | +21° 29′ 22.6″ |
Values are rounded for an observer-friendly overview. Consult the linked SIMBAD record for component-level identifiers, bibliography, measurement provenance and newer catalogue values.
The name Kornephoros
From Greek korynēphoros, “club-bearer,” an epithet suited to Hercules. The name was restored to standardized modern use by the IAU.
Greek-derived Kornephoros emphasizes the hero's club, whereas the constellation's Arabic-derived names often describe the Kneeler's body. Bayer's Alpha and Beta letters do not guarantee brightness order: Rasalgethi received Alpha, but Kornephoros is normally brighter. The IAU assigns the proper name to component Aa within the spectroscopic system. Historical atlases varied in how they drew Hercules's club and limbs, but the star's scientific identity remained fixed through its Bayer designation.
Modern professional catalogues retain identifiers such as the Bayer designation alongside a proper name. The International Astronomical Union standardizes which name belongs to which component—an important distinction for systems whose combined light looks like one star from Earth.
How to find Kornephoros
Locate the Keystone of Hercules, then extend toward the constellation's southwestern side. Kornephoros is the brightest point in the broader figure. Its companion remains spectroscopic, so binoculars are best used to learn the surrounding pattern rather than split the system.
Best on northern late-spring and summer evenings; visible from most inhabited southern latitudes. Visibility on a particular night still depends on latitude, season, time, horizon obstructions, weather and local light pollution. Use the interactive atlas below to check the surrounding field before observing.
Observation checklist
- Look during June through August evenings.
- Use the Keystone first, then expand to the full Hercules outline.
- Expect a steady yellow-white point in small instruments.
- Do not confuse spectroscopic multiplicity with a resolvable visual double.
Interesting facts about Kornephoros
- Kornephoros is brighter than Alpha Herculis.
- It is a single-lined spectroscopic binary.
- The visible star is an evolved yellow giant.
- Its distance is about 148 light-years.
- The name means club-bearer.
Continue from Kornephoros into the night sky
Use the Hercules constellation guide to place this star within its larger pattern. When you are ready to observe, compare dark-sky places, find a nearby observatory, or follow our practical guide to finding a star in the night sky. Symbolically registered names are kept separately in the searchable Star-Register catalogue.
Sources and further reading
Measurements are rounded for readability. Multiple systems, variable stars and distant supergiants can have component-specific or model-dependent values. Survey panels show photographic sky fields, not the physical surface of the star.