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Double star

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526: 228: 1529: 1579: 1603: 1555: 1591: 512:−1 pairs, each giving the separation of one component of the multiple star from another. Codes such as AC are used to denote which components are being measured—in this case, component C relative to component A. This may be altered to a form such as AB-D to indicate the separation of a component from a close pair of components (in this case, component D relative to the pair AB.) Codes such as 1567: 84:, a chance line-of-sight alignment of two stars at different distances from the observer. Binary stars are important to stellar astronomers as knowledge of their motions allows direct calculation of stellar mass and other stellar parameters. The only (possible) case of "binary star" whose two components are separately visible to the naked eye is the case of 218:
The unrelated categories of optical doubles and true binaries are lumped together for historical and practical reasons. When Mizar was found to be a binary, it was quite difficult to determine whether a double star was a binary system or only an optical double. Improved telescopes, spectroscopy, and
516:
may also be used to denote a component which is being measured relative to another component, A in this case. Discoverer designations are also listed; however, traditional discoverer abbreviations such as Δ and Σ have been encoded into a string of uppercase Roman letters, so that, for example, Δ65
282:
is small compared to their common proper motion, the pair is probably physical. When observed over a short period of time, the components of both optical doubles and long-period visual binaries will appear to be moving in straight lines; for this reason, it can be difficult to distinguish between
762:
Zimmerman, Neil; Oppenheimer, Ben R; Hinkley, Sasha; Brenner, Douglas; Parry, Ian R; Sivaramakrishnan, Anand; Hillenbrand, Lynne; Beichman, Charles; Crepp, Justin R; Vasisht, Gautam; Roberts, Lewis C; Burruss, Rick; King, David L; Soummer, Rémi; Dekany, Richard; Shao, Michael; Bouchez, Antonin;
338:
are ADS 16402A and ADS 16402B; and so on. The letters AB may be used together to designate the pair. In the case of multiple stars, the letters C, D, and so on may be used to denote additional components, often in order of increasing separation from the brightest star, A.
91:
Since the beginning of the 1780s, both professional and amateur double star observers have telescopically measured the distances and angles between double stars to determine the relative motions of the pairs. If the relative motion of a pair determines a curved arc of an
253:. In the measures of a visual binary, the position angle will change progressively and the separation between the two stars will oscillate between maximum and minimum values. Plotting the measures in the plane will produce an ellipse. This is the 484:
Visual doubles are also designated by an abbreviation for the name of their discoverer followed by a catalogue number unique to that observer. For example, the pair α Centauri AB was discovered by Father Richaud in 1689, and so is designated
504:, a large database of double and multiple stars, contains over 100,000 entries, each of which gives measures for the separation of two components. Each double star forms one entry in the catalog; multiple stars with 261:
can be computed from it. Although it is expected that the majority of catalogued visual doubles are visual binaries, orbits have been computed for only a few thousand of the over 100,000 known visual double stars.
249:. The position angle specifies the direction in which the stars are separated and is defined as the bearing from the brighter component to the fainter, where north is 0°. These measurements are called 203:, was discovered to be double by Fontenay in 1685. Since that time, the search has been carried out thoroughly and the entire sky has been examined for double stars down to a limiting 219:
photography are the basic tools used to make the distinction. After it was determined to be a visual binary, Mizar's components were found to be spectroscopic binaries themselves.
303:, this is actually a multiple star. Superscripts are also used to distinguish more distant, physically unrelated, pairs of stars with the same Bayer designation, such as 270:
Confirmation of a visual double star as a binary star can be achieved by observing the relative motion of the components. If the motion is part of an
599: 164:
A in 2006. It is only the inability to telescopically observe two separate stars that distinguishes non-visual and visual binaries.
1354: 525: 1224: 232: 1323: 88:(though actually a multiple-star system), but it is not known for certain whether Mizar and Alcor are gravitationally bound. 1087: 1247: 1415: 1270: 879: 763:
Roberts, Jennifer E; Hunt, Stephanie (2010). "Parallactic Motion for Companion Discovery: An M-Dwarf Orbiting Alcor".
517:
has become DUN  65 and Σ2451 has become STF 2451. Further examples of this are shown in the adjacent table.
100:
of both stars, it may be concluded that the pair is in mutual orbit as a binary star. Otherwise, the pair is optical.
1208: 1181: 1150: 1065: 1037: 1016: 863: 839: 746: 1110: 318:
Apart from these pairs, the components of a double star are generally denoted by the letters A (for the brighter,
1278: 1255: 1232: 1118: 1095: 918:, New York: Dover, 1964, pp. 24–25, 38, and p. 61, The present status of double star astronomy, K. Aa. Strand, 501: 1420: 1478: 1347: 160:
Improvements in telescopes can shift previously non-visual binaries into visual binaries, as happened with
24: 326:, star) appended to the designation, of whatever sort, of the double star. For example, the components of 1427: 1395: 669:
system (Aa/Ab/Ba/Bb) and YY Geminorum system (thus Castor Ca/Cb), generally considered a physical system.
1545: 855: 141: 970: 661: 657: 211:
in the northern half of the sky are known to be double stars visible with a 36-inch (910 mm)
1340: 930: 38: 330:(Sirius) are α Canis Majoris A and α Canis Majoris B (Sirius A and Sirius B); the components of 145: 608: 604: 359: 153: 1628: 1532: 1405: 1221: 958: 208: 137: 1509: 926: 782: 300: 8: 1623: 1607: 1463: 946: 915: 702: 122: 786: 1595: 1583: 1468: 798: 772: 204: 180: 794: 327: 1319: 1318:, Wojciak, Kelsey Oseid; Pub. 2017, Ten Speed Press, California, New York,. biblio., 1204: 1177: 1146: 1061: 1033: 1012: 835: 742: 590: 586: 295:. In this case, the components may be denoted by superscripts. An example of this is 292: 275: 62: 54: 1559: 1442: 1400: 802: 790: 635: 573: 398: 304: 257:, the projection of the orbit of the two stars onto the celestial sphere; the true 118:
are unrelated stars that appear close together through chance alignment with Earth.
1173: 1167: 1142: 1132: 1094:, Brian D. Mason, Gary L. Wycoff, and William I. Hartkopf, Astrometry Department, 1057: 1051: 983: 738: 724: 1274: 1251: 1114: 1091: 1084: 883: 831: 817: 494: 424: 85: 77: 1244: 227: 1458: 569: 544: 245: 231:
Astronomers have mistakenly reported observations of a double star in place of
132:
are stars whose binary status was deduced through more esoteric means, such as
105: 1617: 1514: 1499: 1228: 666: 372: 312: 279: 192: 149: 126:
are gravitationally bound stars that are separately visible with a telescope.
101: 97: 1267: 876: 1571: 1473: 1410: 1390: 1385: 676: 672: 627: 595: 490: 385: 196: 188: 172: 1291: 331: 265: 243:, or angular distance, between the two component stars in the sky and the 1437: 1432: 1366: 529:
Artist's impression of the discs around the young stars HK Tauri A and B.
459: 411: 308: 299:(Acrux), whose components are α Crucis and α Crucis. Since α Crucis is a 133: 69: 31: 20: 1107: 296: 239:
Observation of visual double stars by visual measurement will yield the
1504: 631: 617: 613: 176: 1138: 827: 823: 734: 730: 549: 335: 212: 1268:
References and discoverer codes, The Washington Double Star Catalog
1332: 777: 761: 679:
system (thus Mizar Ca/Cb), generally considered a physical system.
1292:"ALMA Finds Double Star with Weird and Wild Planet-forming Discs" 652: 648: 623: 559: 554: 184: 161: 104:
are also studied in this way, although the dynamics of multiple
1380: 564: 1316:
An Illustrated Tour of the Night Sky, What we see in the stars
539: 508:
components will be represented by entries in the catalog for
271: 258: 93: 73: 58: 489:. Other examples include Δ65, the 65th double discovered by 96:, or if the relative motion is small compared to the common 1363: 200: 50: 1566: 315:. These optical pairs are resolvable by the naked eye. 266:
Distinction between binary stars and other double stars
207:
of about 9.0. At least 1 in 18 stars brighter than 9.0
1543: 187:. The identification of other doubles soon followed: 1172:. Dordrecht: D. Reidel Publishing Company. p.  1056:. Dordrecht: D. Reidel Publishing Company. p.  334:are 44 Boötis A and 44 Boötis B; the components of 1203:, Bob Argyle, ed., London: Springer-Verlag, 2004, 1032:, Bob Argyle, ed., London: Springer-Verlag, 2004, 1011:, Bob Argyle, ed., London: Springer-Verlag, 2004, 895: 235:and a faint star in the constellation of Gemini. 191:discovered one of the first double-star systems, 1615: 856:"Artist's Concept of Polaris System - Annotated" 1195: 1193: 111:The following are three types of paired stars: 1108:Sixth Catalog of Orbits of Visual Binary Stars 222: 1348: 870: 108:are more complex than those of binary stars. 16:Pair of stars that appear close to each other 1190: 886:, Leos Ondra, accessed on line May 26, 2007. 576:(thus α Cen C): Actually a three-star system 68:This occurs because the pair either forms a 1079: 1077: 1355: 1341: 1220:Entry 14396-6050, discoverer code RHD 1AB, 1124: 1117:, William I. Hartkopf and Brian D. Mason, 1022: 718: 716: 195:, in 1664, while the bright southern star 776: 697: 695: 693: 72:(i.e. a binary system of stars in mutual 1159: 1074: 1043: 936: 809: 755: 524: 226: 1001: 713: 634:predicts Gamma Cephei should return to 291:Some bright visual double stars have a 1616: 1165: 1130: 1083:"Introduction and Growth of the WDS", 1049: 815: 722: 701: 690: 1336: 1201:Observing and Measuring Double Stars 1030:Observing and Measuring Double Stars 1009:Observing and Measuring Double Stars 343:Double star discoverer designations 1362: 1281:. Accessed on line August 20, 2008. 1258:. Accessed on line August 26, 2008. 1235:. Accessed on line August 20, 2008. 1121:, accessed on line August 20, 2008. 1098:, accessed on line August 20, 2008. 900:. New York: McGraw-Hill. p. 1. 13: 1416:List of most massive star clusters 1254:, Washington Double Star Catalog, 1222:The Washington Double Star Catalog 1085:The Washington Double Star Catalog 580: 533: 14: 1640: 864:Space Telescope Science Institute 1601: 1589: 1577: 1565: 1553: 1528: 1527: 949:, New York: Dover, 1964, p. 260. 322:, star) and B (for the fainter, 1309: 1284: 1279:United States Naval Observatory 1261: 1256:United States Naval Observatory 1238: 1233:United States Naval Observatory 1214: 1119:United States Naval Observatory 1101: 1096:United States Naval Observatory 984:"Masquerading as a double star" 976: 964: 952: 286: 274:, or if the stars have similar 179:, was observed to be double by 988:ESA/Hubble Picture of the Week 904: 889: 848: 502:Washington Double Star Catalog 80:bound to each other) or is an 1: 1421:List of largest star clusters 1141:Publishing Company. pp.  709:. New York: Dover. p. 1. 683: 448:Struve Appendix Catalogue II 61:, especially with the aid of 57:to each other as viewed from 642: 437:Struve Appendix Catalogue I 25:Double star (disambiguation) 19:For the Heinlein novel, see 7: 1428:Hypercompact stellar system 1396:Hypercompact stellar system 795:10.1088/0004-637X/709/2/733 520: 493:, and Σ2451, discovered by 472:Pulkova Appendix Catalogue 278:or the difference in their 223:Observation of double stars 10: 1645: 896:Aitken, Robert G. (1935). 167: 29: 18: 1523: 1487: 1451: 1373: 1245:Format of the current WDS 925:(March 1954), pp. 61–66, 765:The Astrophysical Journal 675:system (Aa/Ab/Ba/Bb) and 283:these two possibilities. 662:Kappa2 Coronae Australis 658:Kappa1 Coronae Australis 30:Not to be confused with 1250:April 12, 2008, at the 39:observational astronomy 1166:Heintz, W. D. (1978). 1131:Heintz, W. D. (1978). 1050:Heintz, W. D. (1978). 816:Heintz, W. D. (1978). 723:Heintz, W. D. (1978). 530: 236: 146:spectroscopic binaries 23:. For other uses, see 1533:Category:Star systems 1406:Dark globular cluster 609:Eta Coronae Australis 528: 230: 920:Astronomical Journal 630:, twin polar stars; 360:Brisbane Observatory 301:spectroscopic binary 154:astrometric binaries 1464:Stellar association 947:Robert Grant Aitken 931:1954AJ.....59...61S 916:Robert Grant Aitken 877:A New View of Mizar 787:2010ApJ...709..733Z 344: 148:), or anomalies in 130:Non-visual binaries 1479:Hypervelocity star 1273:2008-04-13 at the 1113:2009-04-12 at the 1090:2008-09-17 at the 882:2008-03-07 at the 531: 342: 237: 205:apparent magnitude 181:Benedetto Castelli 138:eclipsing binaries 63:optical telescopes 1541: 1540: 1324:978-0-399-57953-0 1296:ESO Press Release 638:by the year 3000. 482: 481: 351:Traditional code 293:Bayer designation 276:radial velocities 1636: 1606: 1605: 1604: 1594: 1593: 1592: 1582: 1581: 1580: 1570: 1569: 1558: 1557: 1556: 1549: 1531: 1530: 1443:Planetary system 1401:Globular cluster 1357: 1350: 1343: 1334: 1333: 1327: 1326:, First edition. 1313: 1307: 1306: 1304: 1302: 1288: 1282: 1265: 1259: 1242: 1236: 1218: 1212: 1197: 1188: 1187: 1163: 1157: 1156: 1128: 1122: 1105: 1099: 1081: 1072: 1071: 1047: 1041: 1026: 1020: 1005: 999: 998: 996: 994: 980: 974: 968: 962: 956: 950: 943:The Binary Stars 940: 934: 912:The Binary Stars 908: 902: 901: 898:The Binary Stars 893: 887: 874: 868: 867: 852: 846: 845: 813: 807: 806: 780: 759: 753: 752: 720: 711: 710: 707:The Binary Stars 699: 591:Alpha Capricorni 574:Proxima Centauri 572:system (AB) and 399:William Herschel 345: 341: 1644: 1643: 1639: 1638: 1637: 1635: 1634: 1633: 1614: 1613: 1612: 1602: 1600: 1590: 1588: 1578: 1576: 1564: 1554: 1552: 1544: 1542: 1537: 1519: 1488:Visual grouping 1483: 1447: 1369: 1361: 1331: 1330: 1314: 1310: 1300: 1298: 1290: 1289: 1285: 1275:Wayback Machine 1266: 1262: 1252:Wayback Machine 1243: 1239: 1219: 1215: 1198: 1191: 1184: 1164: 1160: 1153: 1129: 1125: 1115:Wayback Machine 1106: 1102: 1092:Wayback Machine 1082: 1075: 1068: 1048: 1044: 1027: 1023: 1006: 1002: 992: 990: 982: 981: 977: 969: 965: 957: 953: 941: 937: 909: 905: 894: 890: 884:Wayback Machine 875: 871: 854: 853: 849: 842: 814: 810: 760: 756: 749: 721: 714: 700: 691: 686: 645: 583: 581:Optical doubles 536: 534:Visual binaries 523: 495:F. G. W. Struve 425:F. G. W. Struve 328:α Canis Majoris 289: 268: 225: 170: 123:Visual binaries 116:Optical doubles 106:stellar systems 86:Mizar and Alcor 78:gravitationally 35: 28: 17: 12: 11: 5: 1642: 1632: 1631: 1626: 1611: 1610: 1598: 1586: 1574: 1562: 1539: 1538: 1536: 1535: 1524: 1521: 1520: 1518: 1517: 1512: 1507: 1502: 1497: 1491: 1489: 1485: 1484: 1482: 1481: 1476: 1471: 1466: 1461: 1459:Stellar stream 1455: 1453: 1449: 1448: 1446: 1445: 1440: 1435: 1430: 1425: 1424: 1423: 1418: 1413: 1408: 1403: 1398: 1388: 1383: 1377: 1375: 1371: 1370: 1360: 1359: 1352: 1345: 1337: 1329: 1328: 1308: 1283: 1260: 1237: 1227:2012-07-08 at 1213: 1189: 1182: 1158: 1151: 1123: 1100: 1073: 1066: 1042: 1021: 1000: 975: 963: 951: 935: 903: 888: 869: 847: 840: 808: 771:(2): 733–740. 754: 747: 712: 688: 687: 685: 682: 681: 680: 670: 664: 655: 644: 641: 640: 639: 621: 611: 602: 600:Theta Muscae B 593: 582: 579: 578: 577: 570:Alpha Centauri 567: 562: 557: 552: 547: 542: 535: 532: 522: 519: 480: 479: 476: 473: 469: 468: 465: 462: 456: 455: 452: 449: 445: 444: 441: 438: 434: 433: 430: 427: 421: 420: 417: 414: 408: 407: 404: 403:H I, II, etc. 401: 395: 394: 391: 388: 382: 381: 378: 375: 369: 368: 365: 362: 356: 355: 352: 349: 288: 285: 280:proper motions 267: 264: 255:apparent orbit 246:position angle 224: 221: 201:Southern Cross 169: 166: 158: 157: 127: 119: 102:Multiple stars 82:optical double 15: 9: 6: 4: 3: 2: 1641: 1630: 1627: 1625: 1622: 1621: 1619: 1609: 1599: 1597: 1587: 1585: 1575: 1573: 1568: 1563: 1561: 1551: 1550: 1547: 1534: 1526: 1525: 1522: 1516: 1515:Constellation 1513: 1511: 1508: 1506: 1503: 1501: 1500:Multiple star 1498: 1496: 1493: 1492: 1490: 1486: 1480: 1477: 1475: 1472: 1470: 1467: 1465: 1462: 1460: 1457: 1456: 1454: 1450: 1444: 1441: 1439: 1436: 1434: 1431: 1429: 1426: 1422: 1419: 1417: 1414: 1412: 1409: 1407: 1404: 1402: 1399: 1397: 1394: 1393: 1392: 1389: 1387: 1384: 1382: 1379: 1378: 1376: 1372: 1368: 1365: 1358: 1353: 1351: 1346: 1344: 1339: 1338: 1335: 1325: 1321: 1317: 1312: 1297: 1293: 1287: 1280: 1276: 1272: 1269: 1264: 1257: 1253: 1249: 1246: 1241: 1234: 1230: 1229:archive.today 1226: 1223: 1217: 1210: 1209:1-85233-558-0 1206: 1202: 1196: 1194: 1185: 1183:90-277-0885-1 1179: 1175: 1171: 1170: 1162: 1154: 1152:90-277-0885-1 1148: 1144: 1140: 1137:. Dordrecht: 1136: 1135: 1127: 1120: 1116: 1112: 1109: 1104: 1097: 1093: 1089: 1086: 1080: 1078: 1069: 1067:90-277-0885-1 1063: 1059: 1055: 1054: 1046: 1039: 1038:1-85233-558-0 1035: 1031: 1025: 1018: 1017:1-85233-558-0 1014: 1010: 1004: 989: 985: 979: 972: 967: 960: 955: 948: 944: 939: 932: 928: 924: 921: 917: 913: 907: 899: 892: 885: 881: 878: 873: 865: 861: 857: 851: 843: 841:90-277-0885-1 837: 833: 829: 825: 821: 820: 812: 804: 800: 796: 792: 788: 784: 779: 774: 770: 766: 758: 750: 748:90-277-0885-1 744: 740: 736: 732: 728: 727: 719: 717: 708: 704: 703:Aitken, R. G. 698: 696: 694: 689: 678: 674: 671: 668: 665: 663: 659: 656: 654: 650: 647: 646: 637: 633: 629: 625: 622: 619: 615: 612: 610: 606: 603: 601: 597: 594: 592: 588: 585: 584: 575: 571: 568: 566: 563: 561: 558: 556: 553: 551: 548: 546: 543: 541: 538: 537: 527: 518: 515: 511: 507: 503: 498: 496: 492: 488: 477: 474: 471: 470: 466: 463: 461: 458: 457: 453: 450: 447: 446: 442: 439: 436: 435: 431: 428: 426: 423: 422: 418: 415: 413: 410: 409: 406:H 1, 2, etc. 405: 402: 400: 397: 396: 392: 389: 387: 384: 383: 379: 376: 374: 373:S. W. Burnham 371: 370: 366: 363: 361: 358: 357: 353: 350: 347: 346: 340: 337: 333: 329: 325: 321: 316: 314: 310: 306: 302: 298: 294: 284: 281: 277: 273: 263: 260: 256: 252: 248: 247: 242: 234: 229: 220: 216: 214: 210: 206: 202: 198: 194: 193:Gamma Arietis 190: 186: 182: 178: 174: 165: 163: 155: 151: 150:proper motion 147: 143: 139: 135: 131: 128: 125: 124: 120: 117: 114: 113: 112: 109: 107: 103: 99: 98:proper motion 95: 89: 87: 83: 79: 75: 71: 66: 64: 60: 56: 52: 49:is a pair of 48: 47:visual double 44: 40: 33: 26: 22: 1629:Double stars 1608:Solar System 1494: 1474:Runaway star 1469:Moving group 1411:Open cluster 1391:Star cluster 1386:Dwarf galaxy 1315: 1311: 1299:. Retrieved 1295: 1286: 1263: 1240: 1216: 1200: 1199:p. 307–308, 1169:Double Stars 1168: 1161: 1134:Double Stars 1133: 1126: 1103: 1053:Double Stars 1052: 1045: 1029: 1024: 1008: 1003: 991:. Retrieved 987: 978: 966: 954: 942: 938: 922: 919: 911: 906: 897: 891: 872: 859: 850: 819:Double Stars 818: 811: 768: 764: 757: 726:Double Stars 725: 706: 628:Gamma Cephei 596:Theta Muscae 513: 509: 505: 499: 491:James Dunlop 486: 483: 386:James Dunlop 323: 319: 317: 313:ξ Sagittarii 305:α Capricorni 290: 287:Designations 269: 254: 250: 244: 240: 238: 217: 189:Robert Hooke 171: 159: 142:spectroscopy 129: 121: 115: 110: 90: 81: 67: 55:appear close 46: 42: 36: 1596:Outer space 1584:Spaceflight 1495:Double star 1438:Binary star 1433:Star system 830:. pp.  460:Otto Struve 412:N. Lacaille 348:Discoverer 134:occultation 70:binary star 43:double star 32:Binary star 21:Double Star 1624:Star types 1618:Categories 1505:Star cloud 1028:p. 53–67, 959:Fraunhofer 860:HubbleSite 737:. p.  684:References 636:prominence 632:Precession 618:Messier 40 614:Winnecke 4 309:ξ Centauri 241:separation 177:Ursa Major 1560:Astronomy 1139:D. Reidel 971:Pickering 828:D. Reidel 824:Dordrecht 778:0912.1597 735:D. Reidel 731:Dordrecht 653:Albireo B 649:Albireo A 643:Uncertain 550:p Eridani 354:WDS code 336:ADS 16402 332:44 Boötis 324:secondary 213:telescope 209:magnitude 199:, in the 1510:Asterism 1301:1 August 1271:Archived 1248:Archived 1225:Archived 1111:Archived 1088:Archived 993:25 March 880:Archived 705:(1964). 521:Examples 297:α Crucis 251:measures 1546:Portals 1452:Unbound 1367:systems 1364:Stellar 927:Bibcode 803:6052794 783:Bibcode 624:Polaris 560:Procyon 555:Polaris 545:Capella 320:primary 185:Galileo 168:History 162:Polaris 1381:Galaxy 1322:  1207:  1180:  1149:  1064:  1036:  1015:  1007:p. 2, 973:, 1889 961:, 1814 838:  801:  745:  667:Castor 565:Sirius 311:, and 1572:Stars 1374:Bound 1143:17–18 799:S2CID 773:arXiv 677:Alcor 673:Mizar 587:Alpha 540:Acrux 487:RHD 1 478:STTA 454:STFB 451:Σ II 443:STFA 364:Brs0 272:orbit 259:orbit 233:J 900 197:Acrux 175:, in 173:Mizar 94:orbit 74:orbit 59:Earth 53:that 51:stars 1320:ISBN 1303:2014 1205:ISBN 1178:ISBN 1147:ISBN 1062:ISBN 1034:ISBN 1013:ISBN 995:2013 910:See 836:ISBN 832:4–10 743:ISBN 660:and 651:and 626:and 607:and 598:and 589:and 500:The 475:OΣΣ 467:STT 440:Σ I 432:STF 419:LCL 416:Lac 393:DUN 367:BSO 183:and 41:, a 791:doi 769:709 605:Eta 464:OΣ 380:BU 140:), 45:or 37:In 1620:: 1294:. 1277:, 1231:, 1192:^ 1176:. 1174:19 1145:. 1076:^ 1060:. 1058:12 986:. 945:, 923:59 914:, 862:. 858:. 834:. 826:: 822:. 797:. 789:. 781:. 767:. 741:. 739:17 733:: 729:. 715:^ 692:^ 514:Aa 497:. 429:Σ 390:Δ 377:β 307:, 215:. 156:). 76:, 65:. 1548:: 1356:e 1349:t 1342:v 1305:. 1211:. 1186:. 1155:. 1070:. 1040:. 1019:. 997:. 933:. 929:: 866:. 844:. 805:. 793:: 785:: 775:: 751:. 620:) 616:( 510:n 506:n 152:( 144:( 136:( 34:. 27:.

Index

Double Star
Double star (disambiguation)
Binary star
observational astronomy
stars
appear close
Earth
optical telescopes
binary star
orbit
gravitationally
Mizar and Alcor
orbit
proper motion
Multiple stars
stellar systems
Visual binaries
occultation
eclipsing binaries
spectroscopy
spectroscopic binaries
proper motion
astrometric binaries
Polaris
Mizar
Ursa Major
Benedetto Castelli
Galileo
Robert Hooke
Gamma Arietis

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