Herschel Objects not in the NGC
Only 4 or 5 of Herschel's objects are not listed in the NGC (but 2 of them
have been assigned IC numbers):
Herschel Name RA Dec Notes
H III.363 IC 4051 13:00.9 -28:00 Galaxy in Coma Berenices
H III.382 IC 2995 12:05.8 -27:56 Galaxy in Hydra
H III.969 AR 37 11:32.5 +74:32 Open Cluster in Draco
H V.35 Sh 276 05:41 -02: Diffuse Nebula in Orion; Barnards Loop ?
H III.968? UGC 6090 11:01.7 +75:13 Galaxy in Draco; also assigned non-existing NGC 3500?
In addition, there seem to be two entries not belonging to any objects,
and are not contained in the NGC:
Herschel Name RA Dec Notes
H I.7 12:42.3 +07:48: Either a comet, or re-observation of M49
H II.118 Nonexistent object in Coma near M88
In more detail:
- H I.7
- January 23, 1784; W. Herschel's Sweep 105, measured from 49 Leonis (this may
be a misidentification). Notes: "vB. L. R. The place inac." W.H. describes
it as "A beautiful nebula, not cometic," and first supposed it might be a
reobservation of M61. Later, and by comparing
his drawing, he assumed that his
early identification was probably erroneous: "This remarkable appearance
being no longer in the place it has been observed, we must look upon it as a
very considerable telescopic comet. It was visible in the finder and
resembled on of the bright nebulae of the 'Connoissance de Temps' [Messier's
Catalog] so much, that I took it for one of them till I came to settle its
place; but this not being done till a month or two after the observation, the
opportunity of pursuing and investigating its track was lost. [See Notes,
infra.]"
The value given above for declination is quite uncertain, according to
Herschel.
Based on Herschel's notes and drawing, J.L.E. Dreyer, the author of the NGC,
concluded that, contrary to Herschel's assumption, H I.7 was possibly a
reobservation of M49, because this "nebula" has
a star of mag 12 close to it, which might be that visible in the
drawing.
- H II.118
- April 8, 1784; observed as measured from 6 Comae, with note that it was
observed just following [east of] M88.
Thanks to Bob Erdmann and Richard Wilds for communicating these informations to
me!
- H II.6
-
Another perhaps spurious identification is that of H II.6 (GC 573) with
H I.1 (NGC 1055, GC 591, h 258). This object is described by William
Herschel on December 18, 1783 as preceding 82 Delta Ceti by 1m in RA and
1/2 deg N of it, as "S. C, between 2 L and 1 S st." (small, cometic,
between 2 large [bright] and 1 small [faint] stars). William Herschel
remarks in his notes at the end of the printed catalogue of 1786,
"II.6. This has probably been a telescopic comet, as I have not been
able to find it again, notwithstanding the assistance of a drawing which
represents the telescopic stars in its neighborhood."
Nevertheless, John Herschel included this object, or observation, in his
General Catalogue, gives a position of RA=02:231:35.5,
NPD=89:44:06.9 (1860.0) and repeats his father's description "small,
cometic". In his notes to the GC, he expresses his belief that this
object was actually another comet:
"This was probably really a comet, as indicated by its description,
having been subsequently looked for and not found."
So we arrive at two possible, or probable, telescopic comet sightings by
William Herschel in December 1783 (H II.6) and January 1784 (H I.7).
Please email me any additional
information on any of these entries in Herschel's catalogs, or other
Herschel objects which were perhaps not included in the NGC.
Back to Herschel Catalog page
Hartmut Frommert
(spider@seds.org).
Christine Kronberg
(smil@lrz.uni-muenchen.de)
Last Modification: 8 Feb 1998, 20:00 MET