the northern crown · pronounced koh-ROH-nuh bor-ee-AL-is. Corona Borealis is a small northern constellation whose semicircle of stars genuinely resembles a jeweled crown. Alphecca, the pattern’s bright central gem, makes the arc easy to verify between Boötes and Hercules on spring and early-summer evenings. Ptolemy included the figure among the classical 48, and Greek accounts commonly identify it as the crown given to Ariadne, though other Mediterranean traditions attached different royal and circular imagery to these stars. The constellation contains few bright deep-sky objects, but it rewards variable-star observers. R Coronae Borealis can fade unpredictably when carbon dust obscures it, while the recurrent nova T Coronae Borealis has undergone rare dramatic eruptions. The Corona Borealis Galaxy Cluster lies far beyond amateur naked-eye reach but is scientifically notable. This is an official IAU region rather than simply the visible arc, and it should not be confused with Corona Australis. Its compact shape, bright anchor and clear seasonal placement make it one of the best beginner patterns in the northern sky.
About Corona Borealis
Corona Borealis is one of the 88 constellations recognized by the International Astronomical Union. Its standard three-letter abbreviation is CrB, and astronomers use the genitive form Coronae Borealis when naming stars associated with it. The constellation's reference position lies around right ascension -8.1 hours and declination +32 degrees.
Its location places it in the northern sky. For a typical mid-latitude observer, this part of the celestial sphere is especially well placed during spring evenings. Exact visibility depends on latitude, local horizon, date and time.
History and mythology of Corona Borealis
Historical origin
Ptolemy included the figure among the classical 48, and Greek accounts commonly identify it as the crown given to Ariadne, though other Mediterranean traditions attached different royal and circular imagery to these stars. The constellation contains few bright deep-sky objects, but it rewards variable-star observers.
The modern constellation
Corona Borealis became one of the 88 official constellations standardized by the International Astronomical Union. Its boundary is a coordinate-defined sky region, while the familiar line figure joins only selected stars and has no physical depth.
Reading the cultural record
Names and stories attached to this part of the sky changed across languages, periods and communities. Cultural parallels should be identified from specialist sources rather than presented as interchangeable versions of Corona Borealis.
How to find Corona Borealis
- Use a location-aware chart and observe when Corona Borealis reaches its highest evening altitude; check that the full constellation rises from your latitude.
- Locate Alphecca, magnitude 2.2, then compare its direction with a brighter neighboring constellation rather than relying on line art alone.
- Trace the main pattern toward Nusakan; binoculars reveal the fainter connecting stars while preserving a wide field.
- Move to Abell 2065 with a low-power eyepiece or binoculars, then increase magnification only if its surface brightness permits.
Bright stars in Corona Borealis
Alphecca
Notable star- Magnitude
- 2.2
- Distance
- 75 ly
An eclipsing binary at the crown’s centre and by far the pattern’s brightest star.
Nusakan
Notable star- Magnitude
- 3.7
- Distance
- 114 ly
A binary star on the western side of the arc; its spectrum has unusually strong metallic lines.
Gamma Coronae Borealis
Notable star- Magnitude
- 3.8
- Distance
- 146 ly
A binary system forming part of the crown’s eastern curve.
R Coronae Borealis
Notable star- Magnitude
- variable, usually about 6
- Distance
- about 1,400 ly
Prototype of hydrogen-deficient variables that undergo sudden dust-driven fades.
Deep-sky objects in Corona Borealis
Abell 2065
The central concentration of the very remote Corona Borealis Supercluster.
NGC 6085 and NGC 6086
A paired telescopic challenge embedded in the Abell 2162 galaxy cluster.
T Coronae Borealis
A white-dwarf binary known for rare naked-eye nova eruptions.
Interesting facts about Corona Borealis
- Corona Borealis’s traditional name refers to northern crown, while its official IAU boundary defines a precise region of the sky.
- Alphecca, at magnitude 2.2, is a key star in Corona Borealis. An eclipsing binary at the crown’s centre and by far the pattern’s brightest star.
- Abell 2065 is a notable galaxy cluster in Corona Borealis. The central concentration of the very remote Corona Borealis Supercluster.
- NGC 6085 and NGC 6086, a galaxies, is another observing target within the constellation.
- Ptolemy included the figure among the classical 48, and Greek accounts commonly identify it as the crown given to Ariadne, though other Mediterranean traditions attached different royal and circular imagery to these stars.