William Derham; Phil. Trans. XXXVIII, 70 (1733)

III. Observations of the Appearance among the Fix'd Stars, called Nebulous Stars. By W. Derham, D.D. Canon of Windsor, F.R.S.

HAVING last Autumn made good Observations, with my eight Foot Reflecting Telescope, of the Appearance of the Heavens, called Nebulous Stars, I think it proper to acquaint this Illustrious Society with them, to instigate others to make farther Observations of them, because I think there is much more in them worthy ofthe Inquiry of the Curious, than hath hitherto been imagined, and because I fear I shall not be able to pursue my Observations much farther, by reason my Reflecter loseth its Excellence and Power, by beginning to be tarnished.

But if any one would have a good View of these Nebulosae, it is of absolute Necessity that he makes use of very good Glasses, else all his Labour will be lost, as I found by Experience.

These Appearances in the Heavens, have born the Name Nebulous Stars : But neither are they Stars, nor such Bodies as emit, or reflect Light, as the Sun, Moon, and Stars do; nor are they Congeries, or Clusters of Stars, as the Milky Way : but whitish Areae, like a Collection of Milky Vapours : whence they have their Name.

There are many of them dispersed about, in diverse Parts of the Heavens. This Catalogue of them (which I transcribed from Hevelius's Prodomus Astronomiae) may be of good use to such as are minded to enquire into them.

A Catalogue of the Nebulosae, extracted from Hevelius.

The Places of the Nebulosae   Their R. As-   Their Declinat.
                                     cent. A 1660.   A.D. 1660.

                                     gr.  ' "       gr. ' "

In Andromeda's Girdle,                 6 04 45      39 27 57 N.
In Forehead of Capricorn,            300 02 53      20 01 53 S.
Another preceding the
  Eye of Capricorn,                  301 59 55      19 11 30 S.
Another following it,                302 35 09      19 36 00 S.
One above those, adjoin-
  ing to the Eye of Ca-
  pricorn,                           302 25 31      18 48 58 S. 
Preceding above the 
  Swan's Tail, and last
  in its N. Foot,                    304 54 08      47 54 20 N. 
One following a Star a-
  bove the Swan's Tail,
  out of the Constellation,          312 10 05      53 05 20 N. 
On the outside of Hercu-
  les left Foot,                     264 52 64      48 09 10 N. 
In the left Leg of Hercules,         265 38 37      38 05 50 N. 
On the Top of Hercu-
  les's Head,                        252 24 03      13 18 37 N. 
At the Ear of Pegasus,               332 38 45      03 03 12 N. 
In the Western Border of
  Sobieski's Shield,                 272 32 34      14 23 35 S. 
Under the Beam of the
  Scales of Libra,                   219 26 15      09 16 27 S. 
Above the Back of Ursa
  major,                             183 32 41      60 20 33 N. 
In the third joint of Scor-           12 43 00      19 01 00
  pio's Tail,                       Scorpio Long.       S. Lat.
Between Scorpio's Tail,
  and the Bow of Sagit-               14 32 00      11 25 00
  tarius,                           Scorpio Long.       S. Lat.

Besides these Dr. Halley, in Phil. Trans. No. 347, hath mentioned one in Orion's Sword ; another in Sagittary ; a third in the Centaur (never seen in England) a fourth preceding the right Foot of Antinous ; a fifth in Hercules ; and that in Andromeda's Girdle.
Five of these six I have carefully viewed with my excellent eight Foot Reflecting Telescope, and find them to be Phaenomena much alike ; all except that preceding the right Foot of Antinous, which is not a Nebulose, but a Cluster of Stars, somewhat like that which is the Milky-Way.
Between the other four, I find no material Difference, only some are rounder, some of a more oval Form, without any Fix'd Stars in them to cause their Light; only that in Orion, hath some Stars in it, visible only with the Telescope, but by no Means sufficient to cause the Light of the Nebulose there. But by htese Stars it was, that I first perceived the Distance of the Nebulosae to be greater than that of the Fix'd Stars, and put me upon enquiring into the rest of them. Every one of which I could very visibly, and plainly discern, to be at immense Distance beyond the Fix'd Stars near them, whether visible to the naked Eye, or Telescopick only; yea, they seemed to be as far beyond the Fix'd Stars, as any of those Stars are from Earth.
And now from this Relation of what I have observed from very good, and frequent Views of the Nebulosae, I conclude them certainly not to be Lucid Bodies, that send their Light to us, as the Sun and Moon. Neither are they the combined Light of Clusters of Stars, like that of the Milky-Way : But I take them to be vast Areae, or Regions of Light, infallibly beyond the Fix'd Stars, and devoid of them. I say Regions, meaning Spaces of vast Extent, large enough to appear of such a Size as they do to us, at so great a Distance as they are from us.
And since those Spaces are devoid of Stars, and even that in Orion itself, hath its Stars bearing a very small Proportion to its Nebulose, and they are visible not the Cause of it, I leave it to the great Sagacity and Penetration of this Illustrious Society, to judge whether these Nebulosae are particular Spaces of Light; or rather, whether they may not, in all Probability, be Charms, or Openings into an immense Region of Light, beyond the Fix'd Stars. Because I find in this Opinion most of the Learned in all Ages (both Philosophers, and I may add Divines too) thus far concurred, that there was a Region beyond the Stars. Those that imagined there were Crystalline, or Solid Orbs, thought a Coelum Empyraeum was beyond them and the Primum Mobile : and they, that maintained there were no such Orbs, but that the Heavenly Bodies floated in the Aether, imagined that the Starry Region was not the Bounds of the Universe, but that there was a Region beyond that, which they called the Third Region, and Third Heaven.
To conclude these Remarks, it may be of use to take Notice, that in Hevelius's Nebulosae, some seem to be more large, and remarkable than others; but whether they are really so, or no, I confess I have not had Opportunity to see, except that in Andromeda's Girdle, which is as considerable as any I have seen. In his Maps of the Constellations, the most remarkable are the three near the Eye of Capricorn; that in Hercules's Foot; that in the third Joint of Scorpio's Tail; and that between Scorpio's Tail and the Bow of Sagittary. But if any one is desirous to have a good View of these, or any other of the Nebulosae, it is absolutely necessary that he should make use of very good Glasses, else all his Labour will be in vain, as I found by Experience, and before noted.

Html'ed by H. Frommert

Derham's Catalog of Nebulous Stars
History of the Discovery of the Deepsky Objects
More Deepsky Catalogs and Observing Lists
Some other historical catalogs

Hartmut Frommert (spider@seds.org)
Christine Kronberg (smil@lrz.uni-muenchen.de)

Last Modification: 31 Mar 2001, 23:59 MET