Astronomy:V539 Arae
| Observation data Equinox J2000.0]] (ICRS) | |
|---|---|
| Constellation | Ara[1] |
| Right ascension | 17h 50m 28.393s[2] |
| Declination | −53° 36′ 44.66″[2] |
| Apparent magnitude (V) | 5.62[3] |
| Characteristics | |
| Spectral type | B2 V + B3 V + A1 V[3] |
| U−B color index | −0.64[citation needed] |
| B−V color index | −0.099±0.017[1] |
| Variable type | Algol/SPB[4] |
| Astrometry | |
| Radial velocity (Rv) | −4.3±2.9[5] km/s |
| Proper motion (μ) | RA: +2.517[2] mas/yr Dec.: −12.105[2] mas/yr |
| Parallax (π) | 2.5208 ± 0.1096[2] mas |
| Distance | 1,290 ± 60 ly (400 ± 20 pc) |
| Absolute magnitude (MV) | −1.83/−1.11[6] |
| Orbit[7] | |
| Period (P) | 3.1690854(12) d |
| Eccentricity (e) | 0.0548(15) |
| Inclination (i) | 85.2° |
| Argument of periastron (ω) (secondary) | 118.9(1.2)° |
| Details[8] | |
| V539 Ara A | |
| Mass | 6.239±0.066 M☉ |
| Radius | 4.551±0.019 R☉ |
| Luminosity | 2,000+240−210 L☉ |
| Surface gravity (log g) | 3.9170±0.0029 cgs |
| Temperature | 18,100±500[6] K |
| Rotational velocity (v sin i) | 100[9] km/s |
| Age | 23.2±2.9[10] Myr |
| V539 Ara B | |
| Mass | 5.313±0.060 M☉ |
| Radius | 3.575±0.035 R☉ |
| Luminosity | 980+130−110 L☉ |
| Surface gravity (log g) | 4.0570±0.0084 cgs |
| Temperature | 17,100±500[6] K |
| Rotational velocity (v sin i) | 130[9] km/s |
| Other designations | |
| Database references | |
| SIMBAD | AB |
| A | |
V539 Arae is a multiple star system in the southern constellation of Ara. It has the Bayer designation Nu1 Arae , which is Latinized from ν1 Arae and abbreviated Nu1 Ara or ν1 Ara. This is a variable star system, the brightness of which varies from magnitude 5.71 to 6.24, making it faintly visible to the naked eye under good observing conditions.[12] Based upon an annual parallax shift of 2.52 mas,[2] this system is at a distance of approximately 1,290 light-years (400 parsecs) from Earth. The system is drifting closer to the Sun with a radial velocity of −4 km/s.[5]

In 1930, Ferdinand Johannes Neubauer found that the star (usually called Boss 4496 at the time) is a spectroscopic binary. He did not detect any brightness variability.[14] Eclipses were first reported by E. Schoeffel and U. Kohler in 1965. The period they reported is 1/2 the currently accepted value, because they did not realize that the light curve has a deep secondary minimum.[15][16] In 1996, the secondary component was found to be a slowly pulsating B-type star (SPB) with periods of periods of 1.36, 1.78 and possibly 1.08 days.[17]
The core members of this system, ν1 Ara AB, consist of a pair of B-type main-sequence stars in a detached orbit with a period of 3.169 days and an eccentricity of 0.055.[7] Their respective stellar classifications are B2 V and B3 V, and they have a combined visual magnitude of 5.65. Because the orbital plane lies close to the line of sight from the Earth, this pair form a detached eclipsing binary of the Algol type.[11] The eclipse of the primary causes a decrease of 0.52 in magnitude, while the secondary eclipse decreases the magnitude by 0.43.[18]
At an angular separation of 12.34 arcseconds, is a possible tertiary component of this system; a magnitude 9.40 A-type main-sequence star with a classification of A1 V.[3] A 2005 study of the orbit of the main pair demonstrated an apsidal motion, suggesting the influence of a third body. The initial estimate found an orbital period of 42.3±0.8 years and a mass of 1.63 M☉.[7] In 2022, a more refined study suggested the influence of two stellar objects with masses of 0.41 M☉ and 1.74 M☉.[19]
The system is sometimes referred as Upsilon1 Arae (υ1 Arae), and more generally unlettered.[20]
References
- ↑ 1.0 1.1 Anderson, E.; Francis, Ch. (2012), "XHIP: An extended hipparcos compilation", Astronomy Letters 38 (5): 331, doi:10.1134/S1063773712050015, Bibcode: 2012AstL...38..331A.
- ↑ 2.0 2.1 2.2 2.3 2.4 Vallenari, A. et al. (2022). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy & Astrophysics. doi:10.1051/0004-6361/202243940 Gaia DR3 record for this source at VizieR.
- ↑ 3.0 3.1 3.2 Eggleton, P. P.; Tokovinin, A. A. (September 2008), "A catalogue of multiplicity among bright stellar systems", Monthly Notices of the Royal Astronomical Society 389 (2): 869–879, doi:10.1111/j.1365-2966.2008.13596.x, Bibcode: 2008MNRAS.389..869E.
- ↑ Samus, N. N. et al. (2017), "General Catalogue of Variable Stars", Astronomy Reports, GCVS 5.1 61 (1): 80–88, doi:10.1134/S1063772917010085, Bibcode: 2017ARep...61...80S, http://www.sai.msu.su/gcvs/gcvs/index.htm, retrieved 2025-04-30.
- ↑ 5.0 5.1 Gontcharov, G. A. (2006), "Pulkovo compilation of radial velocities for 35495 stars in a common system", Astronomy Letters 32 (11): 759–771, doi:10.1134/S1063773706110065, Bibcode: 2006AstL...32..759G.
- ↑ 6.0 6.1 6.2 Torres, G. et al. (February 2010), "Accurate masses and radii of normal stars: modern results and applications", The Astronomy and Astrophysics Review 18 (1–2): 67–126, doi:10.1007/s00159-009-0025-1, Bibcode: 2010A&ARv..18...67T.
- ↑ 7.0 7.1 7.2 Wolf, M.; Zejda, M. (July 2005), "Apsidal motion in southern eccentric eclipsing binaries: V539 Ara, GG Lup, V526 Sgr and AO Vel", Astronomy and Astrophysics 437 (2): 545–551, doi:10.1051/0004-6361:20041868, Bibcode: 2005A&A...437..545W.
- ↑ Southworth, John; Bowman, Dominic M. (July 2022), "High-mass pulsators in eclipsing binaries observed using TESS", Monthly Notices of the Royal Astronomical Society 513 (3): 3191–3209, doi:10.1093/mnras/stac875, Bibcode: 2022MNRAS.513.3191S.
- ↑ 9.0 9.1 Wilson, Ralph Elmer (1953), "General catalogue of stellar radial velocities", Carnegie Institute Washington D.C. Publication (Carnegie Institution of Washington), Bibcode: 1953GCRV..C......0W.
- ↑ Tetzlaff, N. et al. (January 2011), "A catalogue of young runaway Hipparcos stars within 3 kpc from the Sun", Monthly Notices of the Royal Astronomical Society 410 (1): 190–200, doi:10.1111/j.1365-2966.2010.17434.x, Bibcode: 2011MNRAS.410..190T.
- ↑ 11.0 11.1 "V* V539 Ara". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=V%2A+V539+Ara.
- ↑ Samus, N. N. et al., V539 Ara, Lomonosov Moscow State University, http://www.sai.msu.su/gcvs/cgi-bin/search2.cgi?search=V539+Ara, retrieved 25 November 2024.
- ↑ Knipe, G. F. G. (September 1971), "The light curve and orbital elements of V539 Arae", Astronomy & Astrophysics 14: 70–77, Bibcode: 1971A&A....14...70K.
- ↑ Neubauer, F. J. (August 1930), "Forty-two Spectroscopic Binary Stars", Publications of the Astronomical Society of the Pacific 42 (248): 235–236, doi:10.1086/124043, Bibcode: 1930PASP...42..235N.
- ↑ Schoeffel, E.; Kohler, U. (January 1965), "Photometric Light-Curves of Bright Southern BV-Stars Eclipsing Binaries", Information Bulletin on Variable Stars 77: 1, Bibcode: 1965IBVS...77....1S.
- ↑ Thackeray, A. D.; Knipe, G. F. G. (1965), "The Eclipsing Variable HD 161783 (BV 420)", Monthly Notes of the Astronomical Society of Southern Africa 24: 109, Bibcode: 1965MNSSA..24..109T.
- ↑ Clausen, J. V. (April 1996), "V539 Arae: first accurate dimensions of a slowly pulsating B star", Astronomy and Astrophysics 308: 151–169, Bibcode: 1996A&A...308..151C.
- ↑ Malkov, O. Yu. et al. (February 2006), "A catalogue of eclipsing variables", Astronomy and Astrophysics 446 (2): 785–789, doi:10.1051/0004-6361:20053137, Bibcode: 2006A&A...446..785M.
- ↑ Wolf, M. et al. (April 2022), "The two eccentric eclipsing binaries in multiple systems: V539 Arae and V335 Serpentis", New Astronomy 92: id. 101708, doi:10.1016/j.newast.2021.101708, Bibcode: 2022NewA...9201708W.
- ↑ Hoffleit, D.; Warren, Jr., W. H. (1991), "Note for HR 6622", The Bright Star Catalogue, http://vizier.u-strasbg.fr/viz-bin/VizieR?-6N&-out.form=H0&//*&-source%3DV/50/notes&HR%3D6622, retrieved 2025-04-30.
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