i Aquarii can refer to several different astronomical objects:
Aquarius is a constellation of the zodiac, between Capricornus and Pisces. Its name is Latin for "water-carrier" or "cup-carrier", and its symbol is , a representation of water. Aquarius is one of the oldest of the recognized constellations along the zodiac. It was one of the 48 constellations listed by the 2nd century astronomer Ptolemy, and it remains one of the 88 modern constellations. It is found in a region often called the Sea due to its profusion of constellations with watery associations such as Cetus the whale, Pisces the fish, and Eridanus the river.
Delta Aquarii, officially named Skat, is the third-brightest star in the constellation of Aquarius. The apparent visual magnitude is 3.3, which can be seen with the naked eye. The distance to this star is about 113 light-years based upon parallax measurements, and it has a close companion.
Gamma Aquarii, or γ Aquarii, is a suspected binary star system in the constellation of Aquarius. It has an apparent visual magnitude of 3.849, making it one of the brighter members of the constellation. Based upon parallax measurements taken during the Hipparcos mission, this star is located at a distance of approximately 164 light-years from the Sun. It is drifting closer to the Sun with a radial velocity of −16 km/s. In 1998, Olin J. Eggen included this star as a candidate member of the Hyades Supercluster.
Alpha Aquarii, officially named Sadalmelik, is a single star in the constellation of Aquarius. The apparent visual magnitude of 2.94 makes this the second-brightest star in Aquarius. Based upon parallax measurements made during the Hipparcos mission, it is located at a distance of roughly 520 light-years from the Sun. It is drifting further away from the Sun with a radial velocity of 7.5 km/s.
Beta Aquarii is a single star in the constellation of Aquarius. It has the official name Sadalsuud, and sometimes is identified as β Aquarii, abbreviated Beta Aqr or β Aqr. Based upon parallax measurements obtained during the Hipparcos mission, this component is located at a distance of approximately 540 light years (165 parsecs) from the Sun. It is drifting further away with a radial velocity of 6.5 km/s. The star serves as an IAU radial velocity standard.
Xi Aquarii is a binary star system in the equatorial constellation of Aquarius. It is visible to the naked eye with an apparent visual magnitude of 4.7. Based upon parallax measurements made during the Hipparcos mission, this system lies at a distance of around 179 light-years from the Sun.
Zeta Aquarii is the Bayer designation for a triple star system, the central star of the "water jar" asterism in the equatorial constellation of Aquarius. The combined apparent visual magnitude of this system is 3.65, which is readily visible to the naked eye. Parallax measurements yield a distance estimate of around 92 light-years from Earth.
Eta Aquarii, Latinized from η Aquarii, is the Bayer designation for a star in the equatorial constellation of Aquarius. It is visible to the naked eye with an apparent visual magnitude of 4.04. The distance to this star, as determined by parallax measurements, is about 168 light-years. It is drifting closer to the Sun with a radial velocity of –8 km/s. Eta Aquarii is near the radiant of a meteor shower named after it.
The Bayer designation Tau Aquarii is shared by two star systems, in the constellation Aquarius:
The Bayer designation ψ Aquarii is shared by three stars/star systems in the constellation Aquarius:
The Bayer designation Omega Aquarii is shared by two star systems, in the constellation Aquarius:
The traditional star name Albulaan refers to two stars in the Aquarius constellation:
Mu Aquarii, Latinized from μ Aquarii, is the Bayer designation for a binary star system in the equatorial constellation of Aquarius. It is visible to the naked eye with a combined apparent visual magnitude of 4.7. Based upon parallax measurements, the distance to this system is about 157 light-years. It is drifting closer to the Sun with a radial velocity of −9.1 km/s.
Omicron Aquarii, Latinized from ο Aquarii, is the Bayer designation for a variable star in the equatorial constellation of Aquarius. Visible to the naked eye, it has an apparent visual magnitude of +4.71. Parallax measurements put it at a distance of roughly 440 light-years from Earth. It is drifting further away with a radial velocity of +11 km/s. The star is a candidate member of the Pisces-Eridanus stellar stream.
Pi Aquarii, Latinized from π Aquarii, is the Bayer designation for a binary star in the equatorial constellation of Aquarius. This system has an apparent visual magnitude of a mean apparent magnitude of +4.57. Based upon parallax measurements, it is located at a distance of roughly 780 light-years from Earth. It is drifting further away with a radial velocity of +4 km/s.
108 Aquarii is a star in the equatorial constellation of Aquarius. 108 Aquarii is the Flamsteed designation, although it also bears the Bayer designation i3 Aquarii and the variable star designation ET Aquarii. It has an apparent visual magnitude of 5.194 and can be seen with the naked eye under suitably dark skies. Based upon an annual parallax shift of 10.23, the distance to this star is 319 light-years.
R Aquarii is a variable star in the constellation Aquarius.
The Bayer designation A Aquarii is shared by two stars in the constellation Aquarius:
b Aquarii refers to several different astronomical objects:
The Bayer designation c Aquarii is shared by two stars in the constellation Aquarius: