Gamma Ophiuchi, Latinized from γ Ophiuchi, also named Bake-eo, is a fourth-magnitude

star A star is a luminous spheroid of plasma (physics), plasma held together by Self-gravitation, self-gravity. The List of nearest stars and brown dwarfs, nearest star to Earth is the Sun. Many other stars are visible to the naked eye at night sk ...

in the

constellation A constellation is an area on the celestial sphere in which a group of visible stars forms Asterism (astronomy), a perceived pattern or outline, typically representing an animal, mythological subject, or inanimate object. The first constellati ...

Ophiuchus Ophiuchus () is a large constellation straddling the celestial equator. Its name comes from the Ancient Greek (), meaning "serpent-bearer", and it is commonly represented as a man grasping a snake. The serpent is represented by the constellati ...

. Together with Beta Ophiuchi, it forms the serpent-holder's right shoulder. The star is visible to the naked eye with an

apparent visual magnitude Apparent magnitude () is a measure of the brightness of a star, astronomical object or other celestial objects like artificial satellites. Its value depends on its intrinsic luminosity, its distance, and any extinction of the object's light ca ...

of +3.75. Based upon an annual parallax shift of as seen from Earth, it is located 103

light-year A light-year, alternatively spelled light year (ly or lyr), is a unit of length used to express astronomical distances and is equal to exactly , which is approximately 9.46 trillion km or 5.88 trillion mi. As defined by the International Astr ...

s from the

Sun The Sun is the star at the centre of the Solar System. It is a massive, nearly perfect sphere of hot plasma, heated to incandescence by nuclear fusion reactions in its core, radiating the energy from its surface mainly as visible light a ...

. It is moving closer to the Sun with a

radial velocity The radial velocity or line-of-sight velocity of a target with respect to an observer is the rate of change of the vector displacement between the two points. It is formulated as the vector projection of the target-observer relative velocity ...

of −7.6 km/s.

Nomenclature

This star is known also as Muliphen, although at least two more stars are known with this name: Gamma Canis Majoris (often spelled as Muliphein) and

Gamma Centauri Gamma Centauri is a binary star system in the southern constellation of Centaurus, which is probably part of a wider system together with Tau Centauri. The system is visible to the naked eye as a single point of light with a combined ...

(often spelled as Muhlifain). Muliphein is the IAU-approved name of Gamma Canis Majoris. This star has the Marshallese name Bake-eo (or Bake Eo, pronounced "bakey-yew"), which refers to the

spondylus ''Spondylus'' is a genus of bivalve molluscs, the only genus in the family Spondylidae and subfamily Spondylinae. They are known in English as spiny oysters or thorny oysters (although they are not, in fact, true oysters, but are related to sc ...

mussel. The

IAU Working Group on Star Names The International Astronomical Union (IAU) established a Working Group on Star Names (WGSN) in May 2016 to catalog and standardize proper names for stars for the international astronomical community. It operates under Division C – Education ...

approved the name Bake-eo for this star on 20 August 2024 and it is now so entered in the IAU Catalog of Star Names.

Description

This is an

A-type main sequence star An A-type main-sequence star (A) or A dwarf star is a main-sequence (hydrogen burning) star of spectral type A and luminosity class (five). These stars have spectra defined by strong hydrogen Balmer absorption lines. They measure between 1.7 ...

with a

stellar classification In astronomy, stellar classification is the classification of stars based on their stellar spectrum, spectral characteristics. Electromagnetic radiation from the star is analyzed by splitting it with a Prism (optics), prism or diffraction gratin ...

of A0 V. Gray et al. (2003) lists a classification of A1VnkA0mA0, indicating it is of type A1 V with the

calcium K-line The Fraunhofer lines are a set of spectral absorption lines. They are dark absorption lines, seen in the optical spectrum of the Sun, and are formed when atoms in the solar atmosphere absorb light being emitted by the solar photosphere. The line ...

and metallic lines of an A0 star. It is approximately 184 million years old and is spinning rapidly with a

projected rotational velocity Stellar rotation is the angular motion of a star about its axis. The rate of rotation can be measured from the spectrum of the star, or by timing the movements of active features on the surface. The rotation of a star produces an equatorial bu ...

of 220 km/s. Gamma Ophiuchi has nearly three times the mass of the Sun and 1.8 times the Sun's radius. The star shines with 29 times the luminosity of the Sun, which is being emitted from its outer atmosphere at an

effective temperature The effective temperature of a body such as a star or planet is the temperature of a black body that would emit the same total amount of electromagnetic radiation. Effective temperature is often used as an estimate of a body's surface temperature ...

of . It is radiating an excess emission of infrared, suggesting the presence of a circumstellar disk of dust at an orbital radius of 64 AU from the host star. The disk was imaged in 2025.

References

{{DEFAULTSORT:Gamma Ophiuchi A-type main-sequence stars Ophiuchi, Gamma Ophiuchus BD+02 3403 Ophiuchi, 62 161868 087108 6771 Bake-eo Circumstellar disks