20 Aquarii, a white main-sequence star in Aquarius

20 Aquarii (HIP 105729)

20 Aquarii is a white main-sequence star in the constellation Aquarius. At 207 light years away, it shines at an apparent visual magnitude of 6.38. It is moving through the Galaxy at a speed of 27.7 km/s relative to the Sun. Its projected Galactic orbit carries it between 19,300 and 24,200 light years from the center of the Galaxy. It will come closest to the Sun 1.9 million years from now when it will brighten to magnitude 5.06 from a distance of 113 light years.

Sky position: RA 21h 24.9m, Dec -3° 24'

Common designations: 20 Aquarii, HIP 105729, HD 203843, HR 8192

Galactic Orbit of 20 Aquarii
(compared to the Sun)

E

ccentricity: 11.2% vs. 16.0%

Angle φ : 159.8°vs. 26.0°

Semi-major axis : 6,677 pc vs. 8,686 pc

Semi-minor axis: 6,636 pc vs. 8,574 pc

Focus-to-center

: 746 pcvs. 1,388 pc

Semilatus rectum : 6,594 pc vs. 8,464 pc

Perigalacticon: 5,932 pc vs. 7,297 pc

Apogalacticon

: 7,423 pcvs. 10,074 pc
  Some Tabulated XHIP Data for 20 Aquarii
(see also: SIMBAD)

Astrometry
2007A&A...474..653V

Position	Proper Motion
Right Ascension:	321.21532843° ±0.65 mas	-6.23 ±0.61 mas/yr.
Declination:	-3.39823520° ±0.36 mas	-49.75 ±0.40 mas/yr.
Galactic Longitude:	49.28591613°	-45.79 mas/yr.
Galactic Latitude:	-35.33345876°	-20.43 mas/yr.

Parallax: 15.73 ± 0.56 mas

Spectrography

Spectral Type: F0 V 1999MSS...C05....0H.

Radial Velocity: -23.20 ±2.90 km/s [A rating] 2006AstL...32..759G.

Iron Abundance [Fe/H]: n/a

Photometry
 

band	magnitude	Abs. Mag.
U
B	6.71	2.70
V	6.38	2.37
R
I	6.03	2.02
J	5.79	1.78
H	5.66	1.65
K	5.62	1.61

B-V: +0.33 V-I: +0.35

Derivations

Heliocentric distance: 63.48 pc (3.6% margin of error)

Galactocentric distance: 7,366 pc

Transverse velocity: 15.1 km/s

3D heliocentric position and motion:

toward:	Galactic center	Galactic rotation	North Galactic Pole
Position ( X, Y, Z)	33.8 pc	39.3 pc	-36.7 pc
Velocity (U, V, W)	-4.2 km/s	-26.0 km/s	8.4 km/s