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58 Aquarii

58 Aquarii
Observation data
Epoch J2000      Equinox J2000
Constellation Aquarius
Right ascension 22h 31m 41.31672s[1]
Declination −10° 54′ 19.8148″[1]
Apparent magnitude (V) 6.39[2]
Characteristics
Evolutionary stage Main sequence (Aa + Ab)
White dwarf (B)[3]
Spectral type A9/F0 V[4] + K + WD[3]
B−V color index 0.290±0.009[2]
Astrometry
Radial velocity (Rv)+4.0±4.3[5] km/s
Proper motion (μ) RA: +77.347 mas/yr[1]
Dec.: −52.472 mas/yr[1]
Parallax (π)13.4137 ± 0.1535 mas[1]
Distance243 ± 3 ly
(74.6 ± 0.9 pc)
Absolute magnitude (MV)2.12[2]
Orbit
PrimaryAa
CompanionAb
Period (P)830±73[6] days
Semi-major axis (a)2.3±0.1 AU[3]
Position (relative to A)[3]
ComponentB
Angular distance132
Projected separation9,940 AU
Details
Aa
Mass1.68[3] M
Radius2.4[3] R
Luminosity11.73[2] L
Surface gravity (log g)4.040+0.065
−0.104
[7] cgs
Temperature6,990[3] K
Metallicity [Fe/H]0.014+0.150
−0.120
[7] dex
Rotational velocity (v sin i)30.0±10.0[8] km/s
Age1.4[3] Gyr
Ab
Mass0.74[3] M
Radius0.67[3] R
Temperature4,540[3] K
B
Mass0.70[3] M
Temperature9,500[3] K
Other designations
CD−11° 5855, GC 31468, HD 213464, HIP 111200, HR 8583, SAO 165147[9]
Database references
SIMBADdata

58 Aquarii, abbreviated 58 Aqr, is a triple star system[3] in the constellation of Aquarius. 58 Aquarii is its Flamsteed designation. It is a sixth magnitude star with an apparent visual magnitude of 6.39,[2] which means it is a challenge to view with the naked eye. Based upon an annual parallax shift of 13.4 mas,[1] it is located at a distance of 243 light years.

The primary component, named 58 Aquarii Aa, has a stellar classification of A9/F0 V,[4] matching a main sequence star with a spectrum showing mixed traits of an A/F-type. It is a chemically peculiar Am star, showing metallic lines with no magnetic field.[8] The star has 1.7 times the mass of the Sun and 2.4 times the Sun's radius.[3] It is radiating 12[2] times the Sun's luminosity from its photosphere at an effective temperature of 7,000 K.[3]

The secondary component, named 58 Aquarii Ab, is a K-type dwarf, with around 70% of the Sun's size and an effective temperature around 4,540 K, separated by 2.3 astronomical units from Aa. It was initially uncovered via astrometry from the Hipparcos spacecraft, and later detected via interferometric observations by Idel Waisberg et al. This inner system will become a common envelope binary, when 58 Aquarii Aa expands in the red giant phase. Mass transfer between components is also expected to occur.[3]

The tertiary component, named 58 Aquarii B, is a widely-separated white dwarf, located at 9,940 astronomical units from the inner pair.[3]

References

  1. ^ a b c d e Brown, A. G. A.; et al. (Gaia collaboration) (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics. 616. A1. arXiv:1804.09365. Bibcode:2018A&A...616A...1G. doi:10.1051/0004-6361/201833051. Gaia DR2 record for this source at VizieR.
  2. ^ a b c d e f Anderson, E.; Francis, Ch. (2012), "XHIP: An extended hipparcos compilation", Astronomy Letters, 38 (5): 331, arXiv:1108.4971, Bibcode:2012AstL...38..331A, doi:10.1134/S1063773712050015, S2CID 119257644.
  3. ^ a b c d e f g h i j k l m n o p q r Waisberg, Idel; Klein, Ygal; Katz, Boaz (2023-10-01). "Hidden Companions to Intermediate-mass Stars. XI. Uncovering a 0.7 M, 2.3 au Companion in the Astrometric Binary HIP 111200 = 58 Aquarii". Research Notes of the American Astronomical Society. 7 (10): 225. Bibcode:2023RNAAS...7..225W. doi:10.3847/2515-5172/ad05d0. ISSN 2515-5172.
  4. ^ a b Houk, N.; Swift, C. (1999), "Michigan catalogue of two-dimensional spectral types for the HD Stars", Michigan Spectral Survey, 5, Bibcode:1999MSS...C05....0H.
  5. ^ Gontcharov, G. A. (November 2006), "Pulkovo Compilation of Radial Velocities for 35495 Hipparcos stars in a common system", Astronomy Letters, 32 (11): 759–771, arXiv:1606.08053, Bibcode:2006AstL...32..759G, doi:10.1134/S1063773706110065, S2CID 119231169.
  6. ^ Perryman, M. A. C.; et al. (April 1997), "The HIPPARCOS Catalogue", Astronomy & Astrophysics, 323: L49 – L52, Bibcode:1997A&A...323L..49P
  7. ^ a b Huber, Daniel; et al. (2016), "The K2 Ecliptic Plane Input Catalog (EPIC) and Stellar Classifications of 138,600 Targets in Campaigns 1-8", The Astrophysical Journal Supplement Series, 224 (1): 2, arXiv:1512.02643, Bibcode:2016ApJS..224....2H, doi:10.3847/0067-0049/224/1/2, S2CID 118621218.
  8. ^ a b Paunzen, E.; et al. (February 2013), "A photometric study of chemically peculiar stars with the STEREO satellites - II. Non-magnetic chemically peculiar stars", Monthly Notices of the Royal Astronomical Society, 429 (1): 119–125, arXiv:1211.1535, Bibcode:2013MNRAS.429..119P, doi:10.1093/mnras/sts318, S2CID 119231581.
  9. ^ "58 Aqr". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved October 24, 2018.
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