HD 93486

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HD 93486
RZChaLightCurve.png
A visual band light curve for RZ Chamaeleontis, plotted from data published by Jørgensen & Gyldenkerne (1975) [1]
Observation data
Epoch J2000.0        Equinox J2000.0 (ICRS)
Constellation Chamaeleon
Right ascension 10h 42m 24.10884s [2]
Declination −82° 02′ 14.1832″ [2]
Apparent magnitude  (V)8.1 –8.5 [3]
Characteristics
Spectral type F5 IV-V (both components) [4]
B−V color index +0.45 [5]
Variable type Algol [6]
Astrometry
Radial velocity (Rv)20±0.6 [7]  km/s
Proper motion (μ)RA: −13.536  mas/yr [2]
Dec.: −45.153  mas/yr [2]
Parallax (π)5.7404 ± 0.0186  mas [2]
Distance 568 ± 2  ly
(174.2 ± 0.6  pc)
Absolute magnitude  (MV)+1.72 [8] (combined)
Orbit [4]
PrimaryRZ Cha A
CompanionRZ Cha B
Period (P)2.8321  d
Semi-major axis (a)12.2  AU [9]
Eccentricity (e)0.00
Periastron epoch (T)2,441,402.4791  JD
Argument of periastron (ω)
(secondary)		0.00°
Semi-amplitude (K1)
(primary)		108.2±0.6 km/s
Semi-amplitude (K2)
(secondary)		107.6±0.9 km/s
Details
combined/mean
Surface gravity (log g)3.91±0.01 [4]   cgs
Metallicity [Fe/H]+0.23±0.10 [10]   dex
Details
A
Mass 1.51 [9]   M☉
Radius 2.29 [11]   R☉
Luminosity 7.94+0.77
−0.70 [10]   L☉
Surface gravity (log g)3.900±0.013 [12]   cgs
Temperature 6,450±150 [11]   K
Rotational velocity (v sin i)39±1 [4]  km/s
Age 2.11 [11]   Gyr
B
Mass 1.40 [11]   M☉
Radius 2.21 [11]   R☉
Luminosity7.94+0.77
−0.70 [10]   L☉
Surface gravity (log g)3.902±0.014 [12]   cgs
Temperature 6,450±150 [11]   K
Rotational velocity (v sin i)41±3 [4]  km/s
Age 3.03 [11]   Gyr
Other designations
RZ Cha, CD−81°391, CPD−81°467, GC  14785, HD  93486, HIP  52381, SAO  258590 [13]
Database references
SIMBAD data

HD 93486, also known as HIP 52381, is a binary star located in the southern circumpolar constellation Chamaeleon near the border with Octans. Its variable star designation is RZ Chamaeleontis (RZ Cha). It has an apparent magnitude ranging from 8.2 to 9.1, [6] which is below the limit for naked eye visibility. Gaia DR3 parallax measurements place the system 568 light years away, [2] and it is currently receding with a heliocentric radial velocity of 20  km/s . [7] At its current distance, HD 93486's average brightness is diminished by 0.53 magnitudes due to interstellar dust. [14] The system has a combined absolute magnitude of +1.72. [8]

In 1964, HD 93486 was discovered to be an eclipsing binary by astronomer W. Strohmeier and colleagues. [15] Four years later, the system was found to be an Algol variable [16] and was given the variable star designation RZ Chamaeleontis in 1974. [17] J. Andersen et al. (1975) calculated a circular orbit of 2.8321 days, [4] which is also its variability period. During this time, RZ Cha drops from photographic magnitude 8.2 to 9.1 when the smaller component is eclipsed, and to 8.8 when the larger one is eclipsed. [6]

Both components have a stellar classification of F5 IV-V, indicating that they are slightly evolved F-type stars with luminosity classes intermediate between a subgiant and a main-sequence star. The primary has 151% the mass of the Sun [9] and 2.29 times the Sun's radius. [11] The secondary has 140% the mass of the Sun and 2.21 times the radius of the Sun. [11] Together, both stars radiate 7.94 times the luminosity of the Sun [18] from their photospheres at an effective temperature of 6,450  K , giving it a combined yellowish-white hue. The system is metal enriched with an iron abundance and is estimated to be 2 to 3 billion years old. [11] Both stars spin modestly, with projected rotational velocities of 39  km/s and 41 km/s respectively. [4]

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<span class="mw-page-title-main">CT Chamaeleontis</span> Star in the constellation Chamaleon

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<span class="mw-page-title-main">Z Chamaeleontis</span> Variable star in the constellation Chamaeleon

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<span class="mw-page-title-main">Epsilon Chamaeleontis</span> Star in the constellation Chamaeleon

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<span class="mw-page-title-main">Zeta Chamaeleontis</span> Variable star in the constellation Chamaeleon

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<span class="mw-page-title-main">Eta Chamaeleontis</span> Star in the constellation Chamaeleon

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Psi<sup>2</sup> Orionis Spectroscopic binary system in the constellation of Orion

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<span class="mw-page-title-main">AI Phoenicis</span> Star in the constellation Phoenix

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<span class="mw-page-title-main">HS Hydrae</span> Triple star in the constellation of Hydra

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<span class="mw-page-title-main">HD 104237</span> Multiple star system in the constellation of Chamaeleon

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<span class="mw-page-title-main">HU Tauri</span> Binary star in the constellation Taurus

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<span class="mw-page-title-main">DR Chamaeleontis</span> Binary star in the constellation Chamaeleon

DR Chamaeleontis, also known as HD 93237, is a star located in the southern circumpolar constellation Chamaeleon. The system has an average apparent magnitude of 5.97, allowing it to be faintly visible to the naked eye. DR Cha is located relatively far at a distance of 1,060 light years based on Gaia DR3 parallax measurements, but is receding with a poorly constrained heliocentric radial velocity of 18 km/s.

<span class="mw-page-title-main">HD 118285</span> SPB star in the constellation Chamaeleon.

HD 118285, also known as HR 5115, is a variable star located in the southern circumpolar constellation Chamaeleon. DY Chamaeleontis is its variable star designation. It has an average apparent magnitude of 6.32, placing it near the limit for naked eye visibility. The object is located relatively far at a distance of 864 light years based on Gaia DR3 parallax measurements but is receding with a heliocentric radial velocity of 18 km/s. At its current distance, HD 118285's brightness is diminished by 0.58 magnitudes due to interstellar dust.

<span class="mw-page-title-main">HD 75747</span> Star in the constellation Chamaeleon

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<span class="mw-page-title-main">T Chamaeleontis</span> T Tauri star; Chamaeleon

T Chamaeleontis, also known as HIP 58285, is a T Tauri star located in the southern circumpolar constellation Chamaeleon. It has an apparent magnitude that ranges from 10.05 to 14.50, which is below the limit for naked eye visibility. Gaia DR3 parallax measurements place the object 335 light years away and it is currently receding with a heliocentric radial velocity of 13.8 km/s. At its current distance, T Cha's average brightness is diminished by 0.31 magnitudes due to extinction from interstellar dust. It has an average absolute magnitude of +6.55.

References

  1. ↑ Jørgensen, H. E.; Gyldenkerne, K. (November 1975). "Four-colour photometry of eclipsing binaries. II. RZ Cha, light curves, photometric elements and determination of helium content". Astronomy and Astrophysics. 44: 343–347. Bibcode:1975A&A....44..343J . Retrieved 16 February 2023.
  2. 1 2 3 4 5 6 Vallenari, A.; et al. (Gaia Collaboration) (2022). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy & Astrophysics . arXiv: 2208.00211 . doi: 10.1051/0004-6361/202243940 . Gaia DR3 record for this source at VizieR.
  3. ↑ Giuricin, G.; Mardirossian, F.; Mezzetti, M.; Predolin, F. (1980). "Revised photometric elements of the detached eclipsing binaries RS Cha, RZ Cha, HS Hya". Astronomy and Astrophysics. 85: 259. Bibcode:1980A&A....85..259G.
  4. 1 2 3 4 5 6 7 Andersen, J.; Gjerloff, H.; Imbert, M. (November 1975). "Spectroscopic observations of eclipsing binaries II: Absolute dimensions, evolutionary state, and helium content of RZ Chamaeleontis". Astronomy and Astrophysics. 44: 349-353. Bibcode:1975A&A....44..349A. ISSN   0004-6361.
  5. ↑ Høg, E.; Fabricius, C.; Makarov, V. V.; Urban, S.; Corbin, T.; Wycoff, G.; Bastian, U.; Schwekendiek, P.; Wicenec, A. (March 2000). "The Tycho-2 catalogue of the 2.5 million brightest stars". Astronomy and Astrophysics. 355: L27–L30. Bibcode:2000A&A...355L..27H. ISSN   0004-6361.
  6. 1 2 3 Samus’, N. N.; Kazarovets, E. V.; Durlevich, O. V.; Kireeva, N. N.; Pastukhova, E. N. (January 2017). "General catalogue of variable stars: Version GCVS 5.1". Astronomy Reports. 61 (1): 80–88. Bibcode:2017ARep...61...80S. doi:10.1134/S1063772917010085. eISSN   1562-6881. ISSN   1063-7729. S2CID   125853869.
  7. 1 2 Pourbaix, D.; Tokovinin, A. A.; Batten, A. H.; Fekel, F. C.; Hartkopf, W. I.; Levato, H.; Morrell, N. I.; Torres, G.; Udry, S. (23 August 2004). "SB9: The ninth catalogue of spectroscopic binary orbits". Astronomy & Astrophysics. 424 (2): 727–732. arXiv: astro-ph/0406573 . Bibcode:2004A&A...424..727P. doi: 10.1051/0004-6361:20041213 . eISSN   1432-0746. ISSN   0004-6361.
  8. 1 2 Anderson, E.; Francis, Ch. (May 2012). "XHIP: An extended hipparcos compilation". Astronomy Letters. 38 (5): 331–346. arXiv: 1108.4971 . Bibcode:2012AstL...38..331A. doi:10.1134/S1063773712050015. eISSN   1562-6873. ISSN   1063-7737. S2CID   119257644.
  9. 1 2 3 Kraicheva, Z.; Popova, E.; Tutukov, A.; Yungelson, L. (July 1980). "Catalogue of physical parameters of spectroscopic binary stars". Bull. Inf. Centre Données Stellaires. 19: 71. Bibcode:1980BICDS..19...71K.
  10. 1 2 3 Kovaleva, D. A. (December 2001). "Age and metallicity estimates for moderate-mass stars in eclipsing binaries". Astronomy Reports. 45 (12): 972–983. Bibcode:2001ARep...45..972K. doi:10.1134/1.1426128. eISSN   1562-6881. ISSN   1063-7729. S2CID   121028634.
  11. 1 2 3 4 5 6 7 8 9 10 Brown, Timothy M. (4 January 2010). "Radii of Rapidly Rotating Stars, with Application to Transiting-Planet Hosts". The Astrophysical Journal. 709 (1): 535–545. arXiv: 0912.1639 . Bibcode:2010ApJ...709..535B. doi: 10.1088/0004-637X/709/1/535 . eISSN   1538-4357. ISSN   0004-637X.
  12. 1 2 Eker, Z.; Bilir, S.; Soydugan, F.; Gökçe, E. Yaz; Soydugan, E.; Tüysüz, M.; Şenyüz, T.; Demircan, O. (2014). "The Catalogue of Stellar Parameters from the Detached Double-Lined Eclipsing Binaries in the Milky Way". Publications of the Astronomical Society of Australia. 31. arXiv: 1403.1583 . Bibcode:2014PASA...31...24E. doi: 10.1017/pasa.2014.17 . eISSN   1448-6083. ISSN   1323-3580.
  13. ↑ "RZ Cha". SIMBAD . Centre de données astronomiques de Strasbourg . Retrieved February 13, 2023.
  14. ↑ Gontcharov, George A.; Mosenkov, Aleksandr V. (28 September 2017). "Verifying reddening and extinction for Gaia DR1 TGAS main sequence stars". Monthly Notices of the Royal Astronomical Society. 472 (4): 3805–3820. arXiv: 1709.01160 . Bibcode:2017MNRAS.472.3805G. doi: 10.1093/mnras/stx2219 . eISSN   1365-2966. ISSN   0035-8711.
  15. ↑ Strohmeier, W.; Knigge, R.; Ott, H. (September 1964). "Bright Southern BV-Stars". Information Bulletin on Variable Stars. 66: 1. Bibcode:1964IBVS...66....1S. ISSN   0374-0676.
  16. ↑ Strohmeier, W.; Mauder, H. (1969). "Discovery and study of bright variable stars". Sky and Telescope. 37 (1): 1. Bibcode:1969S&T....37a...1S. ISSN   0037-6604.
  17. ↑ Geyer, E. H.; Knigge, R. (October 1974). "Improved Light Elements for the Eclipsing Binaries RZ Cha, YZ Cha and DZ Mus". Information Bulletin on Variable Stars. 941: 1. Bibcode:1974IBVS..941....1G. ISSN   0374-0676.
  18. ↑ Malkov, O. Yu. (January 1993). "Catalogue of astrophysical parameters of binary systems". Bulletin d'Information du Centre de Donnees Stellaires. 42: 27. Bibcode:1993BICDS..42...27M. ISSN   1169-8837.

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