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
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 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”
Measures for Class I
Class II Less than 5” Sep
Measures for Class II
Class III 5” to 15” Sep
Measures for Class III
Class IV 15” to 30” Sep
Measures for Class IV
Class V 30” to 60” Sep
Measures for Class V
Class VI > 60” Sep
Measures for Class VI
Cataloue N - all Classes
Measures for Group N
Caroline Sir John
The 40’ Telescope