, German Empire
517: Geneva (from 1967), Switzerland
518: Marine Observatory, Hamburg
519: Meschede
520: Bonn
521: Bamberg
522: Observatory of Strasbourg (Observatoire de Strasbourg)
523: Frankfurt
524: Mannheim
525: Marburg
526: Kiel
527: Altona
528: G?ttingen
529: Christiania
530: Lübeck
531: Collegio Romano, Rome (Osservatorio del Collegio Romano)
532: Munich, Germany (Universit?ts-Sternwarte München, Bogenhausener Sternwarte; a.k.a. K?niglichen Sternwarte zu Bogenhausen)
533: Padua
534: Leipzig (since 1861)
535: Palermo (Osservatorio Astronomico di Palermo "Giuseppe S. Vaiana", Sicily)
536: Berlin-Babelsberg (Berlin Observatoryafter 1913)
537: Urania Observatory, Berlin (Urania Sternwarte)
538: Pola, Croatia (Kaiserlichen und Koniglichen Kriegsmarine Pola Sternwarte; Austro-Hungarian Imperial [and Royal] Naval Observatory in Pola, now Pula, Croatia)
539: Kremsmünster
540: Linz (Davidschlag Observatory; Private Observatory Meyer/Obermair; Sternwarte Davidschlag, Austria)
541: Prague Observatory
542: Falkensee
543: Leipzig (before 1861), German Empire
544: Wilhelm Foerster Observatory, Berlin (Wilhelm-Foerster-Sternwarte)
545: Vienna Observatory (before 1879), Austria-Hungary
546: Oppolzer Observatory, Vienna
547: Breslau
548: Berlin (1835-1913) (Berliner Sternwarte, Berlin Observatory, before 1913)
549: Uppsala (Uppsala Astronomical Observatory(UAO); Astronomiska observatoriet i Uppsala)
550: Schwerin
551: Hurbanovo, formerly O'Gyalla
552: Osservatorio S. Vittore, Bologna (Osservatorio San Vittore, Italy)
553: Chorzów
554: Burgsolms Observatory, Wetzlar
555: Cracow-Fort Ska?a
556: Reintal, near Munich
557: 奥德热幽夫天文台 (Observato? Ond?ejov, 捷克)
558: Warsaw
559: Serra La Nave
560: Madonna di Dossobuono (Osservatorio Madonna di Dossobuono, Italy)
561: Piszkéstet? Stn. (Konkoly) (Piszkéstet? Station, Konkoly Obszervatórium, Budapest)
562: Figl Observatory, Vienna
563: Seewalchen
564: Herrsching
565: Bassano Bresciano (Osservatorio Astronomico di Bassano Bresciano, Italy)
566: Haleakala-NEAT/GEODSS
567: Chions (Osservatorio di Chions; Chaonis Observatory, Italy)
568: Mauna Kea Observatory, Hawaii
569: Helsinki
570: Vilnius (since 1939)
571: Cavriana (Osservatorio "Giordano Bruno", Italy)
572: Cologne
573: Eldagsen
574: Gottolengo
575: La Chaux de Fonds
576: Burwash
577: Metzerlen Observatory
578: Linden Observatory
579: Novi Ligure
580: Graz
581: Sedgefield
582: Orwell Park
583: Odessa-Mayaki
584: Leningrad
585: Kiev comet station
586: Pic du Midi (Observatoire du Pic du Midi, France)
587: Sormano (Osservatorio Astronomico Sormano, Italy)
588: Eremo di Tizzano
589: Osservatorio Astrometrico Santa Lucia Stroncone
590: Metzerlen
591: Resse Observatory
592: Solingen, Germany
593: Monte Argentario
594: Monte Autore
595: Farra d'Isonzo (Osservatorio Astronomico di Farra d'Isonzo, Italy)
596: Colleverde di Guidonia (Osservatorio Colleverde di Guidonia, Italy)
597: Springe
598: Loiano (Osservatorio Astronomico di Loiano, Italy)
599: Campo Imperatore-CINEOS (Osservatorio di Campo Imperatore, Italy)
600-699600: TLC Observatory, Bologna
601: Engelhardt Observatory, Dresden
602: Urania Observatory, Vienna
603: Bothkamp, near Kiel, Germany (Sternwarte Bothkamp, Bothkamp Observatory)