| absmag_v = 1.40[10]
}}{{Starbox detail
| mass =
| radius =
| luminosity =
| luminosity_bolometric = 26.4[10]
| temperature = 9,790[10]
| metal_fe =
| gravity =
| rotational_velocity =
| age_myr =
}}{{Starbox catalog
| names = CD–46 11661, HD 159217, HIP 86092, HR 6537, SAO 228162.[13]
}}{{Starbox reference
|Simbad=sig+Ara
}}{{Starbox end}}Sigma Arae (σ Ara, σ Arae) is the Bayer designation for a star in the southern constellation of Ara. It is visible to the naked eye with an apparent visual magnitude of +4.575.[3] The distance to this star, based upon an annual parallax shift of 8.62 mas,[ is around {{Convert|380|ly|pc|abbr=off|lk=on}}.]
This is an A-type main sequence star with a stellar classification of A0 V.[4] Unusually for an A-type star, X-ray emissions with a luminosity of {{nowrap|4.6 × 1029 erg s−1}} have been detected from Sigma Arae. Normally this is explained by the presence of a lower mass orbiting companion star. However, such a scenario does not appear to hold true for this star. Instead, the signature of a surface magnetic field has been detected with a strength of roughly {{nowrap|128 ± 73 Gauss}}, indicating the source of the X-rays may be surface magnetic activity.[17]
References
1. ^1 2 {{citation | last1=Houk | first1=Nancy | title=Michigan catalogue of two-dimensional spectral types for the HD stars | volume=2 | publication-place=Ann Arbor | publisher=Dept. of Astronomy, University of Michigan | year=1978 | bibcode=1978mcts.book.....H | postscript=. }}
2. ^1 2 3 4 {{citation | last1=Cousins | first1=A. W. J. | title=Revised zero points and UBV photometry of stars in the Harvard E and F regions | journal= Memoirs of the Royal Astronomical Society | volume=77 | pages=223–236 | year=1973 | bibcode=1973MmRAS..77..223C | postscript=. }}
3. ^1 2 3 {{citation | last1=Neff | first1=James E. | last2=Simon | first2=Theodore | title=O VI Observations of the Onset of Convection Zones in Main-Sequence A Stars | journal=The Astrophysical Journal | volume=685 | issue=1 | pages=478–488 |date=September 2008 | doi=10.1086/590423 | bibcode=2008ApJ...685..478N |arxiv = 0805.4459 }}
4. ^1 {{cite simbad | title=* sig Ara | accessdate=2012-08-02 | postscript=. }}
5. ^1 {{citation | last1=Schröder | first1=C. | last2=Hubrig | first2=S. | last3=Schmitt | first3=J. H. M. M. | title=Magnetic fields in A-type stars associated with X-ray emission | journal=Astronomy and Astrophysics | volume=484 | issue=2 | pages=479–486 |date=June 2008 | doi=10.1051/0004-6361:20078963 | bibcode=2008A&A...484..479S }}