18 Scorpii, a yellow main-sequence star in Scorpius
18 Scorpii is a yellow main-sequence star in the constellation Scorpius. At 45 light years away, it shines at an apparent visual magnitude of 5.49.
18 Scorpii (HIP 79672)
18 Scorpii is a yellow main-sequence star in the constellation Scorpius. At 45 light years away, it shines at an apparent visual magnitude of 5.49. 18 Scorpii is the primary component of a multiple-star system. The star's age is estimated to be 2.4 billion years but is certainly no greater than 6.8 billion years. The iron abundance of 18 Scorpii is +0.02 (104.7% of the Sun). It is moving through the Galaxy at a speed of 37.8 km/s relative to the Sun. Its projected Galactic orbit carries it between 20,300 and 30,100 light years from the center of the Galaxy.
Sky position: RA 16h 15.6m, Dec -8° 22.2'
Common designations: 18 Scorpii, HIP 79672, HD 146233, HR 6060, Gliese 616
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Brightest stars in Scorpius:
(list all)
| Rank | Mag. | Star |
| 50 | 5.40 | HD 147722 |
| 51 | 5.41 | HR 5907 |
| 52 | 5.42 | HR 6100 |
| 53 | 5.43 | HR 5942 |
| 54 | 5.43 | 16 Scorpii |
| 55 | 5.46 | HR 6164 |
| 56 | 5.46 | HR 6260 |
| 57 | 5.48 | HR 6221 |
| 58 | 5.48 | 27 Scorpii |
59
| 5.49
) 18 Scorpii
| Rank | Mag. | Star |
| 60 | 5.50 | HR 6007 |
| 61 | 5.53 | HR 6077 |
| 62 | 5.53 | HR 6409 |
| 63 | 5.53 | HR 6583 |
| 64 | 5.58 | HR 6658 |
| 65 | 5.60 | HR 6397 |
| 66 | 5.63 | 4 Scorpii |
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Galactic Orbit of 18 Scorpii
(compared to the Sun)
E
ccentricity: 19.5% vs. 16.0%Angle φ : 88.5°vs. 26.0°
Semi-major axis : 7,719 pc vs. 8,686 pc
Semi-minor axis: 7,571 pc vs. 8,574 pc
Focus-to-center
: 1,503 pcvs. 1,388 pcSemilatus rectum : 7,426 pc vs. 8,464 pc
Perigalacticon: 6,216 pc vs. 7,297 pc
Apogalacticon
: 9,222 pcvs. 10,074 pcSome Tabulated XHIP Data for 18 Scorpii
(see also: SIMBAD)
Astrometry
2007A&A...474..653V
| Position | Proper Motion | |
| Right Ascension: | 243.90472249° ±0.38 mas | 231.10 ±0.80 mas/yr. |
| Declination: | -8.36823642° ±0.25 mas | -494.60 ±0.80 mas/yr. |
| Galactic Longitude: | 4.69590556° | -251.05 mas/yr. |
| Galactic Latitude: | 29.15819271° | -484.78 mas/yr. |
Parallax: 71.94 ± 0.37 mas
Spectrography
Spectral Type: G2V 2003AJ....126.2048G.
Radial Velocity: 11.76 ±0.10 km/s [A rating] 2002ApJS..141..503N, 2005ApJS..159..141V.
Iron Abundance [Fe/H]:
0.02 dex
2009A&A...508L..17R, 2009A&A...501..941H, 2008A&A...487..373S, 2008A&A...480...91S, 2007A&A...468..663T, 2007A&A...465..271R, 2006AJ....131.3069L, 2005ApJS..161..444T, 2005ApJS..159..141V, 2005AJ....129.1063L, 2005A&A...437.1127S, 2004ARep...48..492G, 2004A&A...420..183A, 2004A&A...418..551M, 2000Priv.C........F.
Photometry
| band | magnitude | Abs. Mag. |
| U | ||
| B | 6.14 | 5.43 |
| V | 5.49 | 4.77 |
| R | ||
| I | 4.87 | 4.16 |
| J | 4.67 | 3.95 |
| H | 4.16 | 3.45 |
| K | 4.19 | 3.47 |
B-V: +0.65 V-I: +0.62
Derivations
Heliocentric distance: 13.90 pc (0.5% margin of error)
Galactocentric distance: 7,388 pc
Transverse velocity: 36.0 km/s
3D heliocentric position and motion:
|
toward: |
Galactic center | Galactic rotation | North Galactic Pole |
| Position ( X, Y, Z) | 12.1 pc | 1.0 pc | 6.8 pc |
| Velocity (U, V, W) | 27.1 km/s | -14.4 km/s | -22.2 km/s |