Thực đơn
NGC 523 Tham khảoThực đơn
NGC 523 Tham khảoLiên quan
NGC NGC 5195 NGC 4302 NGC 4993 NGC 404 NGC 4889 NGC 6822 NGC 2392 NGC 6397 NGC 4298Tài liệu tham khảo
WikiPedia: NGC 523 http://cseligman.com/text/atlas/ngc5.htm#523 http://www.rochesterastronomy.org/sn2001/sn2001en.... http://spider.seds.org/ngc/ngc.cgi?523 http://spider.seds.org/ngc/revngcic.cgi?NGC523 http://server1.wikisky.org/starview?object=NGC+523 http://www.wikisky.org/?object=NGC+523&img_source=... http://www.wikisky.org/?object=NGC+523&img_source=... http://www.wikisky.org/?object=NGC+523&img_source=... http://www.wikisky.org/?object=NGC+523&img_source=... http://www.wikisky.org/?object=NGC+523&img_source=...