12 Aquarii

{{short description|Star system in the constellation Aquarius}}

{{Starbox begin}}

{{Starbox observe

| epoch = J2000

| constell = Aquarius

| ra = {{RA|21|04|04.72438}}

| dec = {{DEC|-05|49|23.0347}}

| appmag_v = {{nowrap|5.67 (5.88 + 7.55)}}

}}

{{Starbox character

| class={{nowrap|K0/1 III + A3 V}} or {{nowrap|G4 II + A3+ + (A4)}}

}}

{{Starbox astrometry

| radial_v = {{Val|+1.1|0.3}}

| prop_mo_ra = +20.35

| prop_mo_dec = -6.67

| parallax = 6.50

| p_error = 0.88

| parallax_footnote =

| absmag_v = {{nowrap|0.1 + 1.4 + 1.5}}

}}

{{Starbox detail

| component1 = 12 Aqr Aa/Ab

| mass = 2.6/2.0

| radius =

| luminosity =

| temperature = 5,012/8,511

| gravity =

| metal_fe =

| rotational_velocity =

| age =

| component2 = 12 Aqr B

| mass2 = 1.9

| temperature2 = 8,318

}}

{{Starbox catalog

| names = {{odlist | F=12 Aqr | BD=-06°5664 | HIP=103981 | CCDM=J21041-0549AB | ADS=14592 | WDS=J21041-0549AB }}

| component1 = 12 Aqr A

| names1 = {{odlist | HD=200497 | HR=8059 | SAO=145065 }}

| component2 = 12 Aqr B

| names2 = {{odlist | HD=200496 | HR=8058 | SAO=145064 }}

}}

{{Starbox reference

| Simbad = HIP+103981 | sn=12 Aqr

| Simbad2 = 12+Aqr+A | sn2=12 Aqr A

| Simbad3 = 12+Aqr+B | sn3=12 Aqr B

}}

{{Starbox end}}

12 Aquarii is a triple star system in the zodiac constellation of Aquarius. 12 Aquarii is the Flamsteed designation. It is visible to the naked eye as a dim star with an apparent visual magnitude of 5.67. Parallax measurements by Hipparcos puts it at a distance of some 500 light-years, or 150 parsecs away. The system is moving further from the Earth with a heliocentric radial velocity of +1.1 km/s.

The magnitude 5.88 primary, component A, is itself a binary star with a separation of {{Val|0.05|ul=arcsecond}}–{{Val|0.07|u=arcsecond}} and an orbital period of around {{Convert|6760|days|years|disp=out}}. The brighter member of this duo is a G-type bright giant with a stellar classification of G4 II and 2.6 times the mass of the Sun. Its companion is an early A-type star with double the mass of the Sun. The tertiary component B is magnitude 7.55 A-type main-sequence star at a separation of {{Val|2.44|u=arcsecond}} from the primary.