Subcategories named "Astronomical objects discovered in <year>" should be sorted by discovery year, month, and day. Please use the sortkey YYYYMMDD if all are known. Otherwise, use YYYYMM?? for unknown day, and ? for unknown month and day. Astronomical objects discovered by (before 1500) should be sorted similarly, but omitting the century. For instance, the supernova of 1054 AD would be sorted as 540704 as it was discovered on July 4, (10)54. Use this search to find all pages in these subcategories that are still missing a sortkey.

Pages in this category should be moved to subcategories where applicable. This category may require frequent maintenance to avoid becoming too large. It should directly contain very few, if any, pages and should mainly contain subcategories.