William Herschel's catalog of Deep Sky objects
Thanks to Bill Arnett,
William Herschel's catalog is available online. Bill acknowledges
David Bishop for making it available.
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More material on Friedrich Wilhelm (William) Herschel:
William Herschel got interested in systematically looking for, and observing,
"nebulae" and star clusters when he was presented a copy of the
Messier Catalogue in December, 1781.
Up to that time, he had recorded observations of only 4 nebulae (in particular,
the Orion Nebula M42 and
M43 as early as March 4, 1774).
He started observing these objects about August, 1782, and made his first own
original discovery on September 7, 1782 (of the Saturn Nebula,
After researching for some time how to do these observations, discoveries and
recordings most efficiently, he started a systematical survey with
considerable effort, assisted by his sister Caroline, on October 23, 1783,
with his 18.7-inch aperture, 20-foot focal length reflector, with standard
magnification 157 and a field of view of 15'4".
He made his next discovery on October 28, 1783: NGC 7184, Herschel's H II.1,
a little conspicuous galaxy in Aquarius of 11.2 mag.
Astronomical League's selection of 400 Herschel objects, for which the
AL grants the Herschel Award. This list was compiled by
Brenda Branchett of Deltona, Florida.
full Herschel list of 2500 (actually 2514), which according to
David was originally compiled by
Fr. Lucian J. Kemble (1922-1999),
a Franciscan monk then living in Cochrane, Canada, who later moved to
Lumsden, Saskaschewan, Canada, but the list partially lost;
(astronomer from England, now at ESO)
helped to restore. The list may still be somewhat buggy, though.
Moreover, besides these (mostly typing) errors, Herschel's list is indeed
considerably less reliable than Messier's smaller catalog):
Herschel's catalog contains 36 duplications, 4 entries belong to two objects
each, two further are listed twice as it is uncertain which object
corresponds to them, and 87 objects marked as nonexistent in our lists
(for whatever reason). Thus it seems that actually 2397 objects belong to
the total of 2520 entries in our list (some of these objects are still
multiple stars, or asterism).
- I have created a Herschel 2500 list sorted by Herschel number, available
in html (linked to our pages) or as
plain ascii file.
- I extracted the "Notes" on Herschel's catalog of
David Bishop from Bill's README
- Goto Bill Arnett's
complete Herschel directory.
At that time, Caroline had already started to make a number of own deepsky
discoveries with her smaller Newtonian telescope;
look at her list (of about 13).
In only 1 1/2 years until April 1785 he cataloged 1000 deepsky objects, a
second catalog of 1000 objects followed to 1788 (published 1789), and a
further 500 objects to 1802.
William Herschel was usually carefully avoiding to number the Messier objects,
in appreciation of Messier's prior work.
However, he of course numbered the missing
and the additional (i.e., later added)
objects, as he did not look at them as Messier's "nebulae". Erroneously, he
also numbered some of the Messier objects though, and in some cases, parts of
Look at the complete list.
Almost all of Herschel's objects (even the non-existing, erroneous entries)
have also obtained an NGC number; there are only
four or five exceptions.
As the most renowned astronomer of his time, William Herschel contributed
significantly to most branches of astronomy: Besides searching clusters and
nebulae, he discovered planet Uranus in 1781, two satellites of Uranus, Titania
and Oberon, in 1787, and Saturn's moons Mimas and Enceladus in 1789, he
investigated the proper motion of stars and derived the peculiar motion of the
solar system toward the direction of constellation Hercules, modelled the
Milky Way galaxy from stellar statistics, and speculated about the nature of
the nebulae, including a discussion of the possibility of external island
universes (galaxies) which had been brought up by Kant. He also contributed to
physics (especially optics) and, e.g., discovered the infrared light.
Thanks to Arild Mikalsen from Norway for contributing some corrections
to this page !
Other Deep Sky catalogs suitable for the
History of the Discovery of the Deepsky Objects
Last Modification: 6 Aug 1999, 13:40 MET