Ensiklopedia Dunia

Technopedia Center

Faculty of Engineering and Computer Science
S1 Informatics S1 Information Systems S1 Information Technology S1 Computer Engineering S1 Electrical Engineering S1 Civil Engineering

faculty of Economics and Business
S1 Management S1 Accountancy

Faculty of Letters and Educational Sciences
S1 English literature S1 English language education S1 Mathematics education S1 Sports Education

EQ Tauri - Wikipedia

From Wikipedia, the free encyclopedia

EQ Tauri
Observation data Epoch J2000.0 Equinox J2000.0
A visual band light curve for EQ Tauri, plotted from ASAS-SN^[1] data
Constellation	Taurus
Right ascension	03^h 48^m 13.436^s^[2]
Declination	+22° 18′ 50.92″^[2]
Apparent magnitude (V)	10.5 (-11.03)^[3]
Characteristics
Spectral type	G2^[4]
Variable type	W UMa^[3]
Astrometry

Radial velocity (R_v)	71.95±1.22^[5] km/s
Proper motion (μ)	RA: +69.758 mas/yr^[2] Dec.: −30.628 mas/yr^[2]
Parallax (π)	4.4694 ± 0.0171 mas^[2]
Distance	730 ± 3 ly (223.7 ± 0.9 pc)

Orbit^[6]
Period (P)	0.341348 d
Semi-major axis (a)	2.48±0.03 R_☉^[7]
Eccentricity (e)	0.00
Periastron epoch (T)	2,451,183.9 HJD
Semi-amplitude (K₁) (primary)	112.41±1.43 km/s
Semi-amplitude (K₂) (secondary)	254.38±2.42 km/s
Details
Primary
Mass	1.22±0.04^[7] `M`_☉
Radius	1.14±0.01^[7] `R`_☉
Luminosity	1.32±0.03^[7] `L`_☉
Temperature	5,800±100^[7] K
Secondary
Mass	0.54±0.02^[7] `M`_☉
Radius	0.79±0.01^[7] `R`_☉
Luminosity	0.63±0.02^[7] `L`_☉
Other designations
EQ Tau, TIC 440686937, GSC 01260-00909, 2MASS J03481342+2218509, HV 6189^[8]
Database references
SIMBAD	data

EQ Tauri is a triple star system in the equatorial constellation of Taurus that includes a contact eclipsing binary. The system is too faint to be viewed with the naked eye, having a baseline apparent visual magnitude of 10.5.^[3] During the primary eclipse, the brightness of the system drops to magnitude 11.03, then to 10.97 during the secondary minimum.^[3] The secondary eclipse is total.^[7] Based on parallax measurements, it is located at a distance of approximately 730 light years from the Sun.^[2]

The star HV 6189 was identified as a short-period variable by H. Shapley and E. M. Hughes in 1940,^[9] then was more closely studied by Soviet astronomer V. P. Tsesevich in 1954.^[6] It was determined to be a W UMa-type variable and was noted for being located in the region of the Pleiades open cluster.^[10] An analysis of data from Tsesevich and subsequent observations by B. S. Whitney in 1972 suggested that the period is variable. His observations from Konkoly Observatory showed a period of 8.19 h.^[11] W. R. Benbow and R. L. Mutel built a light curve of the eclipsing variable in 1995 that displayed evidence of an active region on the stellar surface.^[12] Orbital period changes continued to be observed, and in 2002 T. Pribulla and M. Vanko suggested it is caused by a third body in the system. They modeled it as a low mass red dwarf with an orbital period of 50.2 years.^[13]

This is a shallow contact binary system,^[7] belonging to sub-type A of the W Ursae Majoris class.^[3] It has an orbital period of 8.1924 hours^[6] and a semimajor axis of 2.48 times the radius of the Sun. The orbit shows a cyclical change with a period of 22.7 years and an amplitude of 0.0058 days. A transit-like event was observed in 2010.^[7] The more massive component is a solar-type star with a deep convection zone that appears magnetically active with a significant coverage of star spots.^[4]

References

^ "ASAS-SN Variable Stars Database". ASAS-SN Variable Stars Database. ASAS-SN. Retrieved 6 January 2022.
^ ^a ^b ^c ^d ^e Brown, A. G. A.; et al. (Gaia collaboration) (2021). "Gaia Early Data Release 3: Summary of the contents and survey properties". Astronomy & Astrophysics. 649: A1. arXiv:2012.01533. Bibcode:2021A&A...649A...1G. doi:10.1051/0004-6361/202039657. S2CID 227254300. (Erratum: doi:10.1051/0004-6361/202039657e). Gaia EDR3 record for this source at VizieR.
^ ^a ^b ^c ^d ^e Samus', N. N; et al. (2017), "General catalogue of variable stars", Astronomy Reports, GCVS 5.1, 61 (1): 80, Bibcode:2017ARep...61...80S, doi:10.1134/S1063772917010085, S2CID 125853869.
^ ^a ^b Yuan, Jinzhao; Qian, Shengbang (October 2007), "Variation of the period and light curves of the solar-type contact binary EQ Tauri", Monthly Notices of the Royal Astronomical Society, 381 (2): 602–610, Bibcode:2007MNRAS.381..602Y, doi:10.1111/j.1365-2966.2007.11926.x.
^ Bilir, S.; et al. (2005), "Kinematics of W Ursae Majoris type binaries and evidence of the two types of formation", Monthly Notices of the Royal Astronomical Society, 357 (2): 497–517, arXiv:astro-ph/0411291, Bibcode:2005MNRAS.357..497B, doi:10.1111/j.1365-2966.2005.08609.x, S2CID 16274339.
^ ^a ^b ^c Rucinski, Slavek M.; et al. (October 2001), "Radial Velocity Studies of Close Binary Stars. V.", The Astronomical Journal, 122 (4): 1974–1980, arXiv:astro-ph/0106160, Bibcode:2001AJ....122.1974R, doi:10.1086/323106.
^ ^a ^b ^c ^d ^e ^f ^g ^h ⁱ ^j ^k Li, K.; et al. (May 2014), "The Triple Binary Star EQ Tau with an Active Component", The Astronomical Journal, 147 (5): 8, Bibcode:2014AJ....147...98L, doi:10.1088/0004-6256/147/5/98, S2CID 123566937, 98.
^ "EQ Tau", SIMBAD, Centre de données astronomiques de Strasbourg, retrieved 2022-03-13.
^ Shapley, Harlow; Hughes, Emily M. (1940), "Variable stars in high galactic latitudes", Annals of the Astronomical Observatory of Harvard College, 90 (4): 163–175, Bibcode:1940AnHar..90..163S.
^ Artiukhina, N. M. (1961), "Proper Motions of three W UMa Type Stars in the Pleiades Region", Peremennye Zvezdy (in Russian), 13: 366, Bibcode:1961PZ.....13..366A.
^ Whitney, B. S. (February 1972), "The Period of EQ Tauri", Information Bulletin on Variable Stars, 633 (1): 1, Bibcode:1972IBVS..633....1W.
^ Benbow, W. R.; Mutel, R. L. (May 1995), "Eclipse Observations of EQ Tau", Information Bulletin on Variable Stars, 4187 (1): 1, Bibcode:1995IBVS.4187....1B.
^ Pribulla, T.; Vanko, M. (April 2002), "Photoelectric photometry of eclipsing contact binaries: U Peg, YY CrB, OU Ser and EQ Tau", Contributions of the Astronomical Observatory Skalnate Pleso, 32 (1): 79–98, Bibcode:2002CoSka..32...79P.

Tvardovskyi, D. E. (January 2020), "Third components with elliptical orbits in the eclipsing binaries: EQ Tau, IR Cas, IV Cas, RY Aqr & RZ Com", Annales Astronomiae Novae, 1: 231–238, arXiv:1912.12639, Bibcode:2020AANv....1..231T.
Hasanzadeh, A.; et al. (January 2015), "New light curve analysis and period changes of the overcontact binary EQ Tauri", New Astronomy, 34: 262–265, Bibcode:2015NewA...34..262H, doi:10.1016/j.newast.2014.07.013.
Elkhateeb, M. M.; Nouh, M. I. (2014), "A holistic study of the eclipsing binary EQ Tau" (PDF), Journal of Physics and Astronomy Research, 1 (3): 15, arXiv:1406.1661, retrieved 2022-03-13.^{[dead link‍]}
Alton, K. B. (December 2009), "A Multi-year Multi-passband CCD Photometric Study of the W UMa Binary EQ Tauri", The Journal of the American Association of Variable Star Observers, 37 (2): 148, Bibcode:2009JAVSO..37..148A.
Hrivnak, Bruce J.; Lu, Wenxian; Eaton, Jeffery; Kenning, Daniel (August 2006), "Light-Curve Study and Physical Properties of the Contact Binary EQ Tauri", The Astronomical Journal, 132 (2): 960–966, Bibcode:2006AJ....132..960H, doi:10.1086/505691, S2CID 120523899.
Alton, Kevin B. (June 2006), "A Backyard CCD Photometric Study of the Neglected W UMa Binary EQ Tauri", Open European Journal on Variable Stars, 39: 1, Bibcode:2006OEJV...39....1A.
Vaňko, M.; et al. (2004), "New Parameters of the Contact Binary Systems YY CRB and EQ Tau", Baltic Astronomy, 13: 151–155, Bibcode:2004BaltA..13..151V.
Yang, Yulan; Liu, Qingyao (December 2002), "A Photometric Study of the Contact Binary EQ Tauri", The Astronomical Journal, 124 (6): 3358–3363, Bibcode:2002AJ....124.3358Y, doi:10.1086/344763, S2CID 123447240.
Qian, Shengbang; Ma, Yuan (June 2001), "Period Studies of Some Neglected Close Binaries: EP Andromedae, V724 Aquilae, SS Comae, AM Eridani, FZ Orionis, BY Pegasi, EQ Tauri, and NO Vulpeculae", The Publications of the Astronomical Society of the Pacific, 113 (784): 754–763, Bibcode:2001PASP..113..754Q, doi:10.1086/320808, S2CID 121169370.
Buckner, M.; et al. (February 1998), "Eclipse Timing Observations of Three Close Binaries", Information Bulletin on Variable Stars, 4559 (1): 1, Bibcode:1998IBVS.4559....1B.

Constellation of Taurus

Stars

Bayer	α (Aldebaran) β (Elnath) γ (Prima Hyadum) δ¹ (Secunda Hyadum) δ² δ³ ε (Ain) ζ (Tianguan) η (Alcyone) θ¹ θ² (Chamukuy) ι κ¹ κ² λ μ ν ξ ο π ρ σ¹ σ² τ υ φ χ ψ ω¹ ω²
Flamsteed	4 (s) 5 (f) 6 (t) 7 9 10 11 12 13 14 16 (Celaeno) 17 (Electra) 18 19 (Taygeta) 20 (Maia) 21 (Asterope) 22 (Asterope II) 23 (Merope) 24 26 27 (Atlas) 28 (Pleione) 29 (u) 30 (e) 31 32 33 36 37 (A¹) 39 (A²) 40 41 44 (p) 45 46 47 48 51 53 55 56 57 (h) 58 60 62 63 66 (r) 70 71 72 75 76 79 (b) 80 81 83 84 85 88 (d) 89 90 (c) 93 95 96 97 (i) 98 (k) 99 101 103 104 (m) 105 106 (l) 107 108 109 (n) 110 111 113 114 (o) 115 116 117 118 119 120 121 122 125 126 127 128 129 130 131 132 133 134 135 136 137 139 140 44 Eri 49 Eri
Variable	T Y Z RR RV RW RY RZ SU SV SZ TU UX UZ VY XX XZ AA AH BP CD CI CM CQ CT CU CW CY DD DF DG DH DI DL DM DN DO DQ DR DS EQ EU FN FS FU FV GG GI GK GV HK HL HU IK V410 V441 V471 V473 V479 V534 V624 V647 V650 V710 V711 V731 V766 V773 V774 V781 V807 V818 V819 V826 V827 V830 V833 V834 V836 V837 V892 V987 V1038 V1062 V1079 V1116 V1137 V1141 V1143 V1156 V1187 V1229 V1232 V1241 (WX Cas) V1298
HR	1023 1028 1039 1067 1085 1089 1102 1103 1110 1119 1137 1159 1172 1183 1185 1188 1201 1222 1224 1233 1237 1238 1253 1254 1257 1279 1280 1284 1295 1307 1310 1315 1349 1354 1358 1360 1370 1385 1400 1402 1403 1406 1413 1425 1427 1436 1442 1445 1446 1448 1455 1477 1480 1490 1512 1517 1554 1566 1575 1585 1633 1642 1741 1750 1755 1831 1847 1860 1878 1902 1921 1929 1954 1997 2013 2074
HD	21032 21585 23514 23712 24040 24368 24496 26292 27860 28086 28678 29627 29647 36112 37124 38263 38524 245134 285507
Other	2MASS J03552337+1133437 2MASS J04070752+1546457 2MASS J0441+2301 A0535+26 BD +24 692 Butterfly Star CoKu Tau/4 Elias 16 Elias 18 GD 71 Gliese 176 Haro 6-37 HBC 379 HH 30 HII 686 HII 1306 HII 1883 HII 3163 HP Tau/G2 Hubble I 4 HZ 9 IRAS 04239+2436 IRAS 04248+2612 IRAS 04325+2402 IRAS 04381+2540 K2-25 L1489 IRS L1527 L1551 IRS 5 L1521F-IRS MWC 480 PSR B0525+21 PSR B0540+23 PSR J0348+0432 PSR J0538+2813 Teide 1 TMR-1 TMC-1A WD 0346+246 WISE 0410+1502

Exoplanets	Aldebaran b ε Tauri b BD+20 594b HD 24040 b HD 37124 b c d Kojima-1Lb TOI-4603 b

References

Further reading