23 Comae Berenices is a binary star [7] system in the northern constellation of Coma Berenices, situated a few degrees away from the North Galactic Pole. [11] It is visible to the naked eye as a faint, white-hued point of light with an apparent visual magnitude of 4.80. [2] The system is located around 310 light years away from the Sun, based on parallax. [1] It is moving closer to the Earth with a heliocentric radial velocity of −16 km/s. [6]
The components of this system orbit each other with a period of 33 years, a large eccentricity of 0.9, and an angular semimajor axis of 0.219″ . [7] The primary, designated component A, is a magnitude 4.96 [3] star with a stellar classification of A0IV, [4] matching an A-type subgiant that has exhausted the supply of hydrogen at its core and is in the process of evolving into a giant. Bychkov et al. (2009) list it as an Am star with an average field strength of 26×10−4 T . [12]
The primary is 210 [8] million years old and is spinning with a projected rotational velocity of 40 km/s. [8] It has 2.15 [8] times the mass of the Sun and about three [9] times the Sun's radius. The star is radiating 104 [2] times the luminosity of the Sun from its photosphere at an effective temperature of 9,675 K. [8]
Pi Serpentis, Latinized from π Serpentis, is a solitary white-hued star in the constellation Serpens, located in its head, Serpens Caput. Based upon an annual parallax shift of 18.22 mas as seen from Earth, it is located around 179 light years from the Sun. It is visible to the naked eye with an apparent visual magnitude of 4.82.
Chi Serpentis is a solitary star in the Serpens Caput section of the equatorial constellation Serpens. Based upon an annual parallax shift of 14.84 mas as seen from Earth, it is located around 222 light years from the Sun. The star is bright enough to be faintly visible to the naked eye, having an apparent visual magnitude of +5.30.
Omega Ursae Majoris is the Bayer designation for a binary star system in the northern circumpolar constellation of Ursa Major. It is visible to the naked eye with an apparent visual magnitude of 4.61. Based upon an annual parallax shift of 13.24 mas, it is roughly 246 light years from the Sun. At that distance, the visual magnitude of the star is diminished by an extinction factor of 0.11 due to interstellar dust.
Psi Velorum, Latinized from ψ Velorum, is a binary star system in the southern constellation of Vela. Based upon an annual parallax shift of 53.15 mas as seen from Earth, it is located 61.4 light years from the Sun. It is visible to the naked eye with a combined apparent visual magnitude of +3.58. The motion of this system through space makes it a candidate member of the Castor stellar kinematic group.
Pi Virginis is a binary star in the zodiac constellation of Virgo. It is visible to the naked eye with an apparent visual magnitude of 4.64. The distance to this star, based upon parallax measurements, is roughly 380 light years.
Tau Centauri, Latinized from τ Centauri, is a solitary star in the southern constellation of Centaurus. It is visible to the naked eye with an apparent visual magnitude of +3.86. The distance to this star, based upon an annual parallax shift of 24.85 mas, is 131 light years. There is a 98% chance that it is a co-moving companion of Gamma Centauri; the two stars have an estimated separation of 1.7 ly (0.53 pc).
Theta1 Crucis is a spectroscopic binary star system in the southern constellation of Crux. It is visible to the naked eye with an apparent visual magnitude of 4.30m. The distance to this star, as determined using parallax measurements, is around 235 light years.
δ Doradus is a star in the southern constellation of Dorado. Based upon an annual parallax shift of 21.80 mas as seen from Earth, it is located around 150 light years from the Sun. The star is visible to the naked eye with an apparent visual magnitude of +4.34.
HR 9038 is a triple star system located thirty-five light-years away, in the constellation Cepheus. Component A is a spectroscopic binary system with an orbital period of 7.753 days and a combined stellar classification of K3 V. Component B is a red dwarf star that orbits the primary pair every 290 years.
HD 200375 is a binary star system in the equatorial constellation of Aquarius. Their orbit does not yet have a unique solution available.
HD 118889 is a binary star system in the northern constellation of Boötes. It is faintly visible to the naked eye as a point of light with an apparent visual magnitude of 5.57. The system is located at a distance of approximately 196 light years from the Sun based on stellar parallax, but is drifting closer with a radial velocity of −26 km/s.
HD 127726 is a binary star system in the northern constellation of Boötes. The pair consist of a rapidly-rotating A-type main-sequence star and a fainter F-type companion, orbiting each other with a period of 29.93 years and an orbital eccentricity (ovalness) of 0.16. They have a combined apparent visual magnitude of 5.88, which is bright enough to be dimly visible to the naked eye. The system is located at a distance of approximately 240 light years from the Sun.
Upsilon4 Eridani is a close binary star system in the constellation Eridanus. It is visible to the naked eye with an apparent visual magnitude of 3.56. Based upon parallax measurements, the pair are located around 54.6 parsecs (178 ly) from the Sun.
Tau5 Eridani, Latinized from τ5 Eridani, is a binary star system in the constellation Eridanus. It is visible to the naked eye with a combined apparent visual magnitude of 4.26. The distance to this system, as estimated using the parallax technique, is around 293 light years.
Omega Eridani is a binary star system in the constellation Eridanus. It is visible to the naked eye with an apparent visual magnitude is 4.37. The distance to this star, as determined by the parallax method, is around 235 light years.
Tau9 Eridani is a binary star in the constellation Eridanus. It is visible to the naked eye with an apparent visual magnitude of 4.63. The distance to this system can be estimated using the parallax method, which yields a value of roughly 327 light years.
Sigma Herculis, Latinized from σ Her, is a binary star system in the northern constellation of Hercules. It has a combined apparent visual magnitude of 4.18, making it bright enough to be visible to the naked eye. Based upon an annual parallax shift of 10.36 mas as seen from Earth, Sigma Herculis is located about 310 light years away from the Sun.
Mu Lupi is a system of three or four stars in the southern constellation of Lupus. It is visible to the naked eye with an apparent visual magnitude of 4.29 and lies roughly 340 light-years from the Sun.
Tau2 Lupi, Latinized from τ2 Lup, is a binary star system in the constellation Lupus. It is visible to the naked eye with a combined apparent visual magnitude of 4.34. Based upon an annual parallax shift of 10.22 mas as seen from Earth, it is located around 319 light years from the Sun. The two components orbit each other with a period of 26.2 years and a high eccentricity of 0.94. The brighter component is a magnitude 4.93 subgiant star with a stellar classification of F4 IV. Its companion is an A-type star with visual magnitude 5.55 and class A7:.
78 Ursae Majoris is a binary star system in the northern circumpolar constellation of Ursa Major. It is visible to the naked eye as a faint point of light with a combined apparent visual magnitude of 4.93. Parallax estimates by Hipparcos put it at a distance of 83 light-years (25 pc), but it is drifting closer with a radial velocity of −5 km/s. The system is a candidate member of the Ursa Major Moving Group.