Rho Scorpii

ρ Scorpii
Location of ρ Scorpii (circled)
Observation data
Epoch J2000      Equinox J2000
Constellation Scorpius
Right ascension 15h 56m 53.07624s[1]
Declination −29° 12′ 50.6612″ [1]
Apparent magnitude (V) 3.86[2]
Characteristics
Spectral type B2 IV[3]
U−B color index -0.82[2]
B−V color index -0.20[2]
Astrometry
Radial velocity (Rv)−0.40[4] km/s
Proper motion (μ) RA: −15.68[1] mas/yr
Dec.: −24.88[1] mas/yr
Parallax (π)6.91 ± 0.19 mas[1]
Distance470 ± 10 ly
(145 ± 4 pc)
Absolute magnitude (MV)−1.93[5]
Orbit[6]
Period (P)4.0033 d
Eccentricity (e)0.27
Periastron epoch (T)2442178.6060 JD
Argument of periastron (ω)
(secondary)		231°
Semi-amplitude (K1)
(primary)		16.40 km/s
Details
Mass7.94±0.55[3] M☉
Radius5.0[7] R☉
Luminosity (bolometric)3,432[3] L☉
Temperature21,150[3] K
Rotational velocity (v sin i)113[8] km/s
Other designations
Iklil, 5 Scorpii, ADS 9846, CCDM J15569-2913A, FK5 3258, GC 21398, HD 142669, HIP 78104, HR 5928, SAO 183957, CD−28° 11714[9]
Database references
SIMBADdata

Rho Scorpii (ρ Scorpii, abbreviated Rho Sco, ρ Sco) is a double star in the constellation of Scorpius. It has an apparent visual magnitude of +3.87, which is bright enough to be seen with the naked eye. Based upon parallax measurements, it is located approximately 472 light years from the Sun.[1] At that distance, the visual magnitude of the system is reduced by 0.07 due to extinction from interstellar dust.[10] It is a member of the Upper Scorpius OB association.[11]

It has two components, designated Rho Scorpii A and B. Rho Scorpii A is itself a single-lined spectroscopic binary whose components are designated Rho Scorpii Aa (formally named Iklil /ˈɪklɪl/, traditionally the name for several neighboring stars)[12] and Ab.

  1. ^ a b c d e f Cite error: The named reference vanLeeuwen2007 was invoked but never defined (see the help page).
  2. ^ a b c Cite error: The named reference Ducati2002 was invoked but never defined (see the help page).
  3. ^ a b c d Cite error: The named reference Hohle2010 was invoked but never defined (see the help page).
  4. ^ Cite error: The named reference Evans1967 was invoked but never defined (see the help page).
  5. ^ Cite error: The named reference Anderson2012 was invoked but never defined (see the help page).
  6. ^ Cite error: The named reference Pourbaiz2004 was invoked but never defined (see the help page).
  7. ^ Cite error: The named reference cadars was invoked but never defined (see the help page).
  8. ^ Cite error: The named reference Simón-Díaz2014 was invoked but never defined (see the help page).
  9. ^ Cite error: The named reference SIMBAD was invoked but never defined (see the help page).
  10. ^ Cite error: The named reference Shatsky2002 was invoked but never defined (see the help page).
  11. ^ Cite error: The named reference Greelman2015 was invoked but never defined (see the help page).
  12. ^ "Naming Stars". IAU.org. Retrieved 16 December 2017.