223:
20:
84:
147:, since there are no additional design parameters one can vary to eliminate them. With two non-spherical mirrors, such as the Ritchey–Chrétien telescope, coma can be eliminated as well, by making the two mirrors' contribution to total coma cancel. This allows a larger useful field of view. However, such designs still suffer from astigmatism.
1149:
hard-to-test curvatures, and
Ritchey left the project. Both projects were then built with traditional optics. Since then, advances in optical measurement and fabrication have allowed the RCT design to take over – the Hale telescope, dedicated in 1948, turned out to be the last world-leading telescope to have a parabolic primary mirror.
1100:
The hyperbolic curvatures are difficult to test, especially with equipment typically available to amateur telescope makers or laboratory-scale fabricators; thus, older telescope layouts predominate in these applications. However, professional optics fabricators and large research groups test their
197:
can deliver even wider fields up to about 7°. However, the
Schmidt requires a full-aperture corrector plate, which restricts it to apertures below 1.2 meters, while a Ritchey–Chrétien can be much larger. Other telescope designs with front-correcting elements are not limited by the practical
174:
When focused midway between the sagittal and tangential focusing planes, stars appear as circles, making the
Ritchey–Chrétien well suited for wide field and photographic observations. The remaining aberrations of the two-element basic design may be improved with the addition of smaller optical
1148:
to be RCTs. His designs would have provided sharper images over a larger usable field of view compared to the parabolic designs actually used. However, Ritchey and Hale had a falling-out. With the 100-inch project already late and over budget, Hale refused to adopt the new design, with its
214:(MTF) over a range of low spatial frequencies, compared to a full-aperture design such as a refractor. This MTF notch has the effect of lowering image contrast when imaging broad features. In addition, the support for the secondary (the spider) may introduce diffraction spikes in images.
23:
George Willis
Ritchey's original 24-inch (0.6 m) reflecting telescope with a parabolic mirror and two foci: Newtonian and Cassegrain. Part of the Smithsonian's collection, it has been on loan to the Chabot Space and Science Center since
123:. The RCT offers good off-axis optical performance, but its mirrors require sophisticated techniques to manufacture and test. Hence the Ritchey–Chrétien configuration is most commonly found on high-performance professional telescopes.
103:. Ritchey constructed the first successful RCT, which had an aperture diameter of 60 cm (24 in) in 1927 (e.g. Ritchey 24-inch reflector). The second RCT was a 102 cm (40 in) instrument constructed by Ritchey for the
868:
415:
315:
210:
In a
Ritchey–Chrétien design, as in most Cassegrain systems, the secondary mirror blocks a central portion of the aperture. This ring-shaped entrance aperture significantly reduces a portion of the
988:
1132:, used to bend the optical path into more convenient configurations. This article only discusses the mirrors required for forming an image, not those for placing it in a convenient location.
182:. Alternatively, a RCT may use one or several low-power lenses in front of the focal plane as a field-corrector to correct astigmatism and flatten the focal surface, as for example the
1113:, this device was built incorrectly (a reflection from an un-intended surface leading to an incorrect measurement of lens position) leading to the error in the Hubble primary mirror.
704:
1153:
63:
configuration. Since the mid 20th century, a majority of large professional research telescopes have been
Ritchey–Chrétien configurations; some well-known examples are the
538:
1095:
1046:
1019:
796:
769:
736:
609:
119:
As with the other
Cassegrain-configuration reflectors, the Ritchey–Chrétien telescope (RCT) has a very short optical tube assembly and compact design for a given
1347:
1069:
629:
582:
562:
490:
468:
442:
1982:
1729:
108:
88:
1830:
1564:
1268:
804:
326:
1302:
240:
2053:
1927:"The optical design of the 40 in. telescope and of the Irenee DuPont telescope at Las Campanas Observatory, Chile"
879:
178:
Astigmatism can be cancelled by including a third curved optical element. When this element is a mirror, the result is a
1661:
1362:
1174:
2092:
1909:
1343:
163:
1141:
2070:
1855:
1631:
104:
1571:
1426:
1287:
1097:), so both mirrors are hyperbolic. (The primary mirror is typically quite close to being parabolic, however.)
1545:
1385:
798:
of the two mirrors are chosen so as to eliminate third-order spherical aberration and coma; the solution is:
159:
144:
1560:
634:
1840:
1549:
1437:
1358:
1313:
1105:. A Ritchey–Chrétien then requires minimal additional equipment, typically a small optical device called a
231:
211:
199:
1672:
1328:
1695:
1515:
1332:
2116:
2175:
2045:
1746:
1497:
1493:
1474:
1396:
1381:
1170:
1117:
183:
139:. If the mirror is made parabolic, to correct the spherical aberration, then it still suffers from
234:
of the primary and secondary mirrors, respectively, in a two-mirror
Cassegrain configuration are:
1926:
1835:
1780:
179:
1810:
1750:
1530:
1508:
1411:
1110:
497:
64:
1875:
1116:
Incorrect null correctors have led to other mirror fabrication errors as well, such as in the
2103:
1582:
1238:
1223:
1197:
96:
1074:
2135:
1991:
1973:
1938:
1850:
1710:
1586:
1448:
1208:
1024:
997:
774:
747:
709:
587:
155:
136:
72:
60:
59:). The RCT has a wider field of view free of optical errors compared to a more traditional
41:
135:, will always have aberrations. If the mirror is spherical, it will suffer primarily from
8:
1765:
1597:
1456:
1257:
132:
2139:
1995:
1942:
1051:
158:. However, the two-surface design does suffer from fifth-order coma, severe large-angle
1845:
1620:
1234:
1219:
1157:
614:
567:
547:
475:
453:
427:
1109:
that makes the hyperbolic primary look spherical for the interferometric test. On the
95:
The
Ritchey–Chrétien telescope was invented in the early 1910s by American astronomer
2049:
1977:
1954:
1905:
1601:
1253:
1161:
187:
222:
100:
1999:
1946:
1422:
1298:
1283:
52:
2026:
1676:
2132:
Reflecting
Telescope Optics I. Basic Design Theory and its Historical Development
1806:
1795:
1736:
68:
1272:
2093:"Advanced Techniques for Measuring Primary Mirrors for Astronomical Telescopes"
1725:
1609:
1482:
1370:
1193:
1182:
1145:
1106:
1102:
742:
194:
48:
2004:
1816:
The 0.208 m LOng Range Reconnaissance Imager (LORRI) camera on board the
2169:
1754:
1590:
1575:
1430:
1404:
1291:
1242:
1227:
1201:
151:
140:
56:
1958:
1817:
1699:
1519:
445:
120:
198:
problems of making a multiply-curved Schmidt corrector plate, such as the
1950:
1691:
45:
470:
is the back focal length (the distance from the secondary to the focus),
1773:
1642:
1534:
1501:
1400:
1128:
In practice, each of these designs may also include any number of flat
1761:
1665:
1646:
1553:
1336:
150:
The basic Ritchey–Chrétien two-surface design is free of third-order
1624:
1605:
1523:
1478:
1366:
1178:
584:, the known quantities are the focal length of the primary mirror,
19:
1783:, infrared space telescope in an Earth-trailing orbit (retired by
1791:
1317:
1135:
83:
1718:
1703:
1684:
1680:
1654:
1321:
863:{\displaystyle K_{1}=-1-{\frac {2}{M^{3}}}\cdot {\frac {B}{D}}}
2134:. Vol. 1. Springer-Verlag: Berlin, Heidelberg, New York.
410:{\displaystyle R_{2}=-{\frac {2DB}{F-B-D}}=-{\frac {2B}{M-1}}}
1769:
1714:
1635:
1613:
1538:
1486:
1460:
1415:
1389:
1374:
1351:
1306:
1276:
1261:
1246:
1212:
1186:
2077:
1784:
1650:
1441:
611:, and the distance to the focus behind the primary mirror,
190:; this can allow a field-of-view up to around 3° diameter.
1732:(the final telescope made by G. Ritchey before his death).
310:{\displaystyle R_{1}=-{\frac {2DF}{F-B}}=-{\frac {2F}{M}}}
2156:
An acre of glass: a history and forecast of the telescope
2071:
The Hubble Space Telescope Optical Systems Failure Report
1452:
1152:
169:
1799:
1348:
Aryabhatta Research Institute of Observational Sciences
1077:
1054:
1027:
1000:
882:
807:
777:
750:
712:
637:
617:
590:
570:
550:
500:
478:
456:
430:
329:
243:
983:{\displaystyle K_{2}=-1-{\frac {2}{(M-1)^{3}}}\left}
1254:
Visible and Infrared Survey Telescope for Astronomy
131:A telescope with only one curved mirror, such as a
1899:
1089:
1063:
1040:
1013:
982:
862:
790:
763:
730:
698:
623:
603:
576:
556:
532:
484:
462:
436:
409:
309:
1983:Monthly Notices of the Royal Astronomical Society
1730:United States Naval Observatory Flagstaff Station
226:Diagram of a Ritchey–Chrétien reflector telescope
89:United States Naval Observatory Flagstaff Station
2167:
55:designed to eliminate off-axis optical errors (
107:; that telescope is still in operation at the
1900:Rutten, Harrie; van Venrooij, Martin (2002).
1831:List of largest optical reflecting telescopes
1630:The 2.0 m Himalayan Chandra Telescope of the
1136:Examples of large Ritchey–Chrétien telescopes
2153:
2129:
1924:
1876:"Classical and aplanatic two-mirror systems"
2090:
1971:
492:is the distance between the two mirrors and
1978:"A simple wide-field Cassegrain telescope"
1565:National Astronomical Observatory (Mexico)
1123:
2003:
1269:Southern Astrophysical Research Telescope
1207:The four 8.2 m telescopes comprising the
1772:dedicated to the search for Earth-sized
1233:The two 8.0 m telescopes comprising the
1151:
221:
126:
82:
18:
1893:
1303:Cerro Tololo Inter-American Observatory
205:
2168:
2098:. Ph.D. Thesis, University of Arizona.
699:{\displaystyle D=f_{1}(F-b)/(F+f_{1})}
170:Further corrections by a third element
2068:
2039:
2027:"Effects of the aperture obstruction"
1873:
1867:
1796:University College London Observatory
1820:space craft, currently beyond Pluto.
1511:currently in orbit around the Earth.
1925:Bowen, I.S.; Vaughan, A.H. (1973).
1882:. Notes on amateur telescope optics
741:For a Ritchey–Chrétien system, the
109:Naval Observatory Flagstaff Station
13:
1363:Roque de los Muchachos Observatory
1314:Eastern Anatolia Observatory (DAG)
1175:Roque de los Muchachos Observatory
40:) is a specialized variant of the
14:
2187:
1344:3.6 m Devasthal Optical Telescope
1192:The two 10.0 m telescopes of the
2069:Allen, Lew; et al. (1990).
1874:Sacek, Vladimir (14 July 2006).
1662:Molėtai Astronomical Observatory
1414:telescope at mount Calar Alto, (
175:elements near the focal plane.
16:Specialized Cassegrain telescope
2147:
1794:design Perren Telescope at the
1632:Indian Astronomical Observatory
1496:telescope (modified design) at
540:is the secondary magnification.
105:United States Naval Observatory
87:The 40-inch (1.0 m) Ritchey at
2123:
2084:
2062:
2033:
2019:
1965:
1918:
1572:Kitt Peak National Observatory
1436:The 3.4 m INO340 Telescope at
1427:Kitt Peak National Observatory
1288:Kitt Peak National Observatory
1144:(1917) and the 200-inch (5 m)
1140:Ritchey intended the 100-inch
959:
944:
924:
911:
693:
674:
666:
654:
519:
507:
1:
1904:. Willmann-Bell. p. 67.
1861:
1813:in Victoria, British Columbia
1546:Leoncito Astronomical Complex
1386:European Southern Observatory
1160:truss telescope, part of the
1142:Mount Wilson Hooker telescope
1856:Schmidt–Cassegrain telescope
1438:Iranian National Observatory
1359:Telescopio Nazionale Galileo
212:modulation transfer function
7:
2158:. Johns Hopkins Univ Press.
1824:
1395:The 3.5 m ARC telescope at
162:, and comparatively severe
10:
2192:
2042:Modern Optical Engineering
1329:Anglo-Australian Telescope
217:
78:
30:Ritchey–Chrétien telescope
2040:Smith, Warren J. (2008).
1696:Pico dos Dias Observatory
1673:Mont-Mégantic Observatory
1516:Thai National Observatory
1333:Siding Spring Observatory
533:{\displaystyle M=(F-B)/D}
114:
2046:McGraw-Hill Professional
1841:Lurie–Houghton telescope
1809:CCT-32 telescope at the
1747:Embry-Riddle Observatory
1660:The 1.65 m telescope at
1559:The 2.12 m telescope at
1498:Apache Point Observatory
1494:Sloan Digital Sky Survey
1475:Nordic Optical Telescope
1397:Apache Point Observatory
1382:New Technology Telescope
1312:The 3.94 m telescope at
1171:Gran Telescopio Canarias
1118:New Technology Telescope
2005:10.1093/mnras/177.1.25P
1836:List of telescope types
1798:in Mill Hill, London, (
1781:Spitzer Space Telescope
1709:The 1.3 m telescope at
1619:The 2.0 m telescope at
1570:The 2.1 m telescope at
1124:Additional flat mirrors
180:three-mirror anastigmat
2111:Cite journal requires
1811:University of Victoria
1751:Daytona Beach, Florida
1531:Calar Alto Observatory
1509:Hubble Space Telescope
1412:Calar Alto Observatory
1165:
1111:Hubble Space Telescope
1091:
1090:{\displaystyle M>1}
1065:
1042:
1015:
984:
864:
792:
765:
732:
700:
625:
605:
578:
558:
534:
486:
464:
438:
411:
311:
227:
99:and French astronomer
92:
65:Hubble Space Telescope
25:
2154:Zirker, J.B. (2005).
2130:Wilson, R.N. (1996).
1583:Otto Struve Telescope
1466:The 2.56 m effective
1239:Mauna Kea Observatory
1224:Mauna Kea Observatory
1198:Mauna Kea Observatory
1155:
1092:
1066:
1043:
1041:{\displaystyle K_{2}}
1016:
1014:{\displaystyle K_{1}}
985:
865:
793:
791:{\displaystyle K_{2}}
766:
764:{\displaystyle K_{1}}
733:
731:{\displaystyle B=D+b}
701:
626:
606:
604:{\displaystyle f_{1}}
579:
559:
535:
487:
465:
439:
412:
312:
225:
200:Lurie–Houghton design
127:Two-mirror foundation
97:George Willis Ritchey
86:
22:
2091:Burge, J.H. (1993).
2048:. pp. 508–510.
1951:10.1364/AO.12.001430
1880:telescope-optics.net
1851:Reflecting telescope
1787:on 30 January 2020).
1711:Skinakas Observatory
1587:McDonald Observatory
1449:VLT Survey Telescope
1209:Very Large Telescope
1075:
1052:
1025:
998:
880:
805:
775:
748:
710:
635:
615:
588:
568:
548:
498:
476:
454:
428:
327:
241:
206:Aperture obstruction
156:spherical aberration
137:spherical aberration
73:Very Large Telescope
61:reflecting telescope
42:Cassegrain telescope
2140:1996rtob.book.....W
1996:1976MNRAS.177P..25H
1943:1973ApOpt..12.1430B
1766:Paranal Observatory
1713:, in the island of
1598:Liverpool Telescope
1533:telescope at mount
1457:Paranal Observatory
1258:Paranal Observatory
133:Newtonian telescope
1846:Maksutov telescope
1764:telescopes at the
1621:Rozhen Observatory
1235:Gemini Observatory
1166:
1158:RC Optical Systems
1087:
1064:{\displaystyle -1}
1061:
1038:
1011:
980:
860:
788:
761:
728:
696:
621:
601:
574:
554:
530:
482:
460:
434:
407:
307:
232:radii of curvature
228:
186:telescope and the
93:
26:
2080:. NASA-TM-103443.
2055:978-0-07-147687-4
1937:(77): 1430–1435.
1726:Ritchey Telescope
1602:robotic telescope
1162:PROMPT Telescopes
973:
934:
858:
845:
624:{\displaystyle b}
577:{\displaystyle D}
557:{\displaystyle B}
485:{\displaystyle D}
463:{\displaystyle B}
444:is the effective
437:{\displaystyle F}
405:
376:
305:
284:
51:and a hyperbolic
2183:
2161:
2159:
2151:
2145:
2143:
2127:
2121:
2120:
2114:
2109:
2107:
2099:
2097:
2088:
2082:
2081:
2075:
2066:
2060:
2059:
2044:(4th ed.).
2037:
2031:
2030:
2023:
2017:
2016:
2014:
2012:
2007:
1976:(October 1976).
1972:Harmer, C.F.W.;
1969:
1963:
1962:
1922:
1916:
1915:
1902:Telescope Optics
1897:
1891:
1890:
1888:
1887:
1871:
1779:The 0.85 m
1744:
1742:
1561:San Pedro Martir
1472:
1470:
1423:WIYN Observatory
1299:Blanco telescope
1284:Mayall Telescope
1220:Subaru telescope
1194:Keck Observatory
1096:
1094:
1093:
1088:
1070:
1068:
1067:
1062:
1047:
1045:
1044:
1039:
1037:
1036:
1020:
1018:
1017:
1012:
1010:
1009:
989:
987:
986:
981:
979:
975:
974:
966:
935:
933:
932:
931:
906:
892:
891:
869:
867:
866:
861:
859:
851:
846:
844:
843:
831:
817:
816:
797:
795:
794:
789:
787:
786:
770:
768:
767:
762:
760:
759:
737:
735:
734:
729:
705:
703:
702:
697:
692:
691:
673:
653:
652:
630:
628:
627:
622:
610:
608:
607:
602:
600:
599:
583:
581:
580:
575:
563:
561:
560:
555:
539:
537:
536:
531:
526:
491:
489:
488:
483:
469:
467:
466:
461:
443:
441:
440:
435:
416:
414:
413:
408:
406:
404:
393:
385:
377:
375:
358:
347:
339:
338:
316:
314:
313:
308:
306:
301:
293:
285:
283:
272:
261:
253:
252:
53:secondary mirror
2191:
2190:
2186:
2185:
2184:
2182:
2181:
2180:
2176:Telescope types
2166:
2165:
2164:
2152:
2148:
2128:
2124:
2112:
2110:
2101:
2100:
2095:
2089:
2085:
2073:
2067:
2063:
2056:
2038:
2034:
2025:
2024:
2020:
2010:
2008:
1970:
1966:
1923:
1919:
1912:
1898:
1894:
1885:
1883:
1872:
1868:
1864:
1827:
1807:DFM Engineering
1792:Astelco Systems
1760:The four 1.0 m
1740:
1739:
1737:DFM Engineering
1468:
1467:
1138:
1126:
1103:interferometers
1076:
1073:
1072:
1053:
1050:
1049:
1032:
1028:
1026:
1023:
1022:
1005:
1001:
999:
996:
995:
965:
940:
936:
927:
923:
910:
905:
887:
883:
881:
878:
877:
850:
839:
835:
830:
812:
808:
806:
803:
802:
782:
778:
776:
773:
772:
755:
751:
749:
746:
745:
743:conic constants
711:
708:
707:
687:
683:
669:
648:
644:
636:
633:
632:
616:
613:
612:
595:
591:
589:
586:
585:
569:
566:
565:
549:
546:
545:
544:If, instead of
522:
499:
496:
495:
477:
474:
473:
455:
452:
451:
429:
426:
425:
394:
386:
384:
359:
348:
346:
334:
330:
328:
325:
324:
294:
292:
273:
262:
260:
248:
244:
242:
239:
238:
220:
208:
188:VISTA telescope
172:
164:field curvature
129:
117:
81:
69:Keck telescopes
17:
12:
11:
5:
2189:
2179:
2178:
2163:
2162:
2146:
2122:
2113:|journal=
2083:
2061:
2054:
2032:
2018:
1964:
1931:Applied Optics
1917:
1910:
1892:
1865:
1863:
1860:
1859:
1858:
1853:
1848:
1843:
1838:
1833:
1826:
1823:
1822:
1821:
1814:
1803:
1788:
1777:
1758:
1733:
1722:
1707:
1688:
1669:
1658:
1645:telescopes at
1639:
1628:
1617:
1610:Canary Islands
1594:
1579:
1568:
1557:
1542:
1527:
1512:
1505:
1490:
1483:Canary Islands
1464:
1445:
1434:
1419:
1408:
1393:
1378:
1371:Canary Islands
1355:
1340:
1325:
1310:
1295:
1280:
1265:
1250:
1231:
1216:
1205:
1190:
1183:Canary Islands
1146:Hale Telescope
1137:
1134:
1125:
1122:
1107:null corrector
1086:
1083:
1080:
1060:
1057:
1048:are less than
1035:
1031:
1008:
1004:
992:
991:
978:
972:
969:
964:
961:
958:
955:
952:
949:
946:
943:
939:
930:
926:
922:
919:
916:
913:
909:
904:
901:
898:
895:
890:
886:
871:
870:
857:
854:
849:
842:
838:
834:
829:
826:
823:
820:
815:
811:
785:
781:
758:
754:
727:
724:
721:
718:
715:
695:
690:
686:
682:
679:
676:
672:
668:
665:
662:
659:
656:
651:
647:
643:
640:
620:
598:
594:
573:
553:
542:
541:
529:
525:
521:
518:
515:
512:
509:
506:
503:
493:
481:
471:
459:
449:
448:of the system,
433:
419:
418:
403:
400:
397:
392:
389:
383:
380:
374:
371:
368:
365:
362:
357:
354:
351:
345:
342:
337:
333:
318:
317:
304:
300:
297:
291:
288:
282:
279:
276:
271:
268:
265:
259:
256:
251:
247:
219:
216:
207:
204:
195:Schmidt camera
171:
168:
128:
125:
116:
113:
101:Henri Chrétien
80:
77:
49:primary mirror
15:
9:
6:
4:
3:
2:
2188:
2177:
2174:
2173:
2171:
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2150:
2141:
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2133:
2126:
2118:
2105:
2094:
2087:
2079:
2072:
2065:
2057:
2051:
2047:
2043:
2036:
2028:
2022:
2006:
2001:
1997:
1993:
1989:
1985:
1984:
1979:
1975:
1968:
1960:
1956:
1952:
1948:
1944:
1940:
1936:
1932:
1928:
1921:
1913:
1911:0-943396-18-2
1907:
1903:
1896:
1881:
1877:
1870:
1866:
1857:
1854:
1852:
1849:
1847:
1844:
1842:
1839:
1837:
1834:
1832:
1829:
1828:
1819:
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1812:
1808:
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1793:
1789:
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1778:
1775:
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1755:United States
1752:
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1734:
1731:
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1694:telescope on
1693:
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1677:Mont-Mégantic
1675:telescope on
1674:
1670:
1667:
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1652:
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1517:
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1101:mirrors with
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896:
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855:
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847:
840:
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818:
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739:
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680:
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670:
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660:
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645:
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618:
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592:
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510:
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501:
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423:
422:
401:
398:
395:
390:
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381:
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372:
369:
366:
363:
360:
355:
352:
349:
343:
340:
335:
331:
323:
322:
321:
302:
298:
295:
289:
286:
280:
277:
274:
269:
266:
263:
257:
254:
249:
245:
237:
236:
235:
233:
224:
215:
213:
203:
201:
196:
191:
189:
185:
181:
176:
167:
165:
161:
157:
153:
148:
146:
142:
138:
134:
124:
122:
112:
110:
106:
102:
98:
90:
85:
76:
74:
70:
66:
62:
58:
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39:
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2155:
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2125:
2104:cite journal
2086:
2064:
2041:
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2021:
2009:. Retrieved
1987:
1981:
1967:
1934:
1930:
1920:
1901:
1895:
1884:. Retrieved
1879:
1869:
1818:New Horizons
1700:Minas Gerais
1692:Perkin-Elmer
1520:Doi Inthanon
1273:Cerro Pachón
1139:
1130:fold mirrors
1129:
1127:
1115:
1099:
993:
872:
740:
543:
446:focal length
420:
319:
229:
209:
192:
177:
173:
149:
130:
121:focal length
118:
94:
71:and the ESO
37:
33:
29:
27:
1974:Wynne, C.G.
1581:The 2.08 m
1544:The 2.15 m
1492:The 2.50 m
1447:The 2.65 m
1421:The 3.50 m
1380:The 3.58 m
1357:The 3.58 m
1169:The 10.4 m
160:astigmatism
145:astigmatism
44:that has a
2076:(Report).
1886:2010-04-24
1862:References
1805:The 0.8 m
1790:The 0.8 m
1774:exoplanets
1735:The 1.0 m
1724:The 1.0 m
1690:The 1.6 m
1671:The 1.6 m
1643:Pan-STARRS
1641:The 1.8 m
1634:, Hanle, (
1596:The 2.0 m
1535:Calar Alto
1529:The 2.2 m
1514:The 2.4 m
1507:The 2.4 m
1502:New Mexico
1410:The 3.5 m
1401:New Mexico
1327:The 3.9 m
1297:The 4.0 m
1282:The 4.0 m
1267:The 4.1 m
1252:The 4.1 m
1218:The 8.2 m
994:Note that
46:hyperbolic
36:or simply
2160:, p. 317.
2011:29 August
1990:: 25–30.
1762:SPECULOOS
1666:Lithuania
1647:Haleakala
1554:Argentina
1337:Australia
1056:−
954:−
918:−
903:−
897:−
848:⋅
828:−
822:−
661:−
514:−
399:−
382:−
370:−
364:−
344:−
290:−
278:−
258:−
2170:Category
1959:20125543
1825:See also
1625:Bulgaria
1606:La Palma
1550:San Juan
1524:Thailand
1479:La Palma
1367:La Palma
1179:La Palma
1156:A 41 cm
2136:Bibcode
1992:Bibcode
1939:Bibcode
1728:at the
1384:at the
1318:Erzurum
1301:at the
1256:at the
1071:(since
631:, then
218:Mirrors
79:History
2144:P. 454
2052:
1957:
1908:
1719:Greece
1704:Brazil
1685:Canada
1681:Quebec
1655:Hawaii
1504:, U.S.
1322:Turkey
1245:) and
1164:array.
421:where
115:Design
67:, the
2096:(PDF)
2074:(PDF)
1770:Chile
1745:8 at
1715:Crete
1636:India
1614:Spain
1604:) on
1539:Spain
1487:Spain
1461:Chile
1416:Spain
1390:Chile
1375:Spain
1352:India
1307:Chile
1277:Chile
1262:Chile
1247:Chile
1213:Chile
1187:Spain
24:2004.
2117:help
2078:NASA
2050:ISBN
2013:2017
1955:PMID
1906:ISBN
1785:NASA
1651:Maui
1442:Iran
1342:The
1082:>
1021:and
873:and
771:and
706:and
564:and
320:and
230:The
193:The
184:SDSS
154:and
152:coma
143:and
141:coma
57:coma
2000:doi
1988:177
1947:doi
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1177:on
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2106:}}
2102:{{
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977:]
971:D
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912:(
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819:=
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694:)
689:1
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678:F
675:(
671:/
667:)
664:b
658:F
655:(
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642:=
639:D
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597:1
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552:B
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524:/
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517:B
511:F
508:(
505:=
502:M
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458:B
432:F
417:,
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391:B
388:2
379:=
373:D
367:B
361:F
356:B
353:D
350:2
341:=
336:2
332:R
303:M
299:F
296:2
287:=
281:B
275:F
270:F
267:D
264:2
255:=
250:1
246:R
91:.
32:(
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