The Herschel Double Star Object Listings

Sir William Herschel (1738 - 1822 ), his sister Caroline  (1750-1848), and his son Sir John Herschel (1792 - 1871) are credited with the discovery and documentation of roughly 2518 objects in the night sky, now known as the Herschel Objects, to include the famous Herschel 400 Observing List, the H2 Observing List. In his “classifications” system, no reference to the term “Galaxy” was made. Today, we know that roughly 75% of the Herschel objects are indeed “Galaxies”. But to them, they appeared as “Nebulae”. In addition to his DSO discoveries as outlined above, Herschel was very busy with Double Stars as well. He discovered and documented over 800 (827 minus Dups and Non-Documented objects) of them, and categorized them into the groups as shown below.  During 1821, he discovered a number of additional objects, which were grouped in “Catalogue N”, a collection of various separations. Bruce MacEvoy has documented his “restoration” of the Herschel Double Star List of the over 800 objects at his website: http://www.handprint.com/ASTRO/herschel.html.   My spreadsheets linked below are based upon his work. Herschel     Herschel Double Star Excel Spreadsheets -   Groups  1-2-3   4-5-6-N  Double Star Classifications:     Shows Common Names, WDS Numbers, and Flamsteed/Bayer .      Designations. Links to the imaged objects. Last 200 Observations               1782 / 1784:        Class I “Most Difficult” (096) Measures for Class I Class II Less than 5” Sep (103) Measures for Class II Class III 5” to 15” Sep (108) Measures for Class III Class IV 15” to 30” Sep (128) Measures for Class IV Class V  30” to 60” Sep (131)   Measures for Class V Class VI > 60” Sep (112)   Measures for Class VI 1821: Cataloue N - all Classes (128) Measures for Group N

The 40’ Telescope