ARCHINAL(M0): Archinal catalog of nonexistent RNGC clusters (19930530)
FILE: archinal.m0 (229 objects)
CONTENTS: Archinal catalog of nonexistent RNGC clusters
DATASET: This file comes in HyperSky dataset M-9, version 19930530. Availability on HyperSky CD-ROM: Vol. 1 (1993)
DESCRIPTION: This datafile contains a total of 229 misidentified or missing NGC star clusters which have not been satisfactorily located since their discovery in the 18th and 19th centuries, as compiled by Brent A. Archinal of the U.S. Naval Observatory, and presented in Monograph Number 1 of the Webb Society. In particular, the RNGC (Revised New General Catalog of Nonstellar Astronomical Objects, Sulentic and Tift, 1977) lists a relatively large number of NGC star clusters as nonexistent (or "type 7"), and contains errors related to other clusters and asterisms.
The monograph itself contains corrected and expanded RNGC information, as well as notes on all known modern observations of these objects (except in the case of a few well-known ones), plus many historical observations. All relevant observations by William and John Herschel are also included.
Of the 229 objects in the monograph catalog, one object was found probably nonexistent and 5 were found to be apparent duplicates of other NGC objects. The monograph and HyperSky catalogs give these six a status of "NO". Another 99 objects were were confirmed to exist in some form, though they are not always clusters (3 are galaxies, for instance). The monograph and HyperSky catalogs give these objects a status of "OK". For the remaining 124 objects, insufficient information was found to confirm or deny the object's existence. The monograph and HyperSky catalogs give these six a status of "YES", meaning that further observations and investigation are needed.
The Archinal catalog is a result of the collaborative work of a number of people in addition to the author. Foremost among many are Alister Ling, Brian Skiff, and Harold Corwin, Jr. The catalog is also an example of what can be accomplished by amateur astronomers working in a professional manner. Such projects are typical of those encouraged by the Webb Society, who have published the monograph associated with this catalog. Monograph copies may be obtained from the Webb Society at the following address:
Webb Society
96 Marmion Road
Southsea, Hants PO5 2BB
England
Internet: amateur@phastr.soton.ac.uk
The monograph and catalog author may be reached at the following address:
Brent A. Archinal
Earth Orientation Parameters Division
U.S. Naval Observatory
3450 Massachusetts Avenue, N.W.
Washington, D.C. 20392 U.S.A.
Internet: BAA@CasA.USNO.Navy.mil
Usage note: In order to easily find objects from this catalog in a general field, you can use HyperSky options to highlight all objects from this catalog with horizontal tickmarks, vertical tickmarks, or both.
DATA: The HyperSky datafile contains the following catalog data:
POSITION: Right Ascension and Declination are the catalog positions for equinix 2000.
MAG: Most objects in the catalog were not given magnitudes. For some clusters Archinal (see below) does provide either an approximate total visual magnitude, or failing that the magnitude of the brightest cluster stars. The HyperSky value may be either; hence this number should be used with caution.
TY: The approximate HyperSky object type, based on the description by Archinal (see below).
IDENTIFICATION: The NGC number of the object in all but one case, where a Herschel number is used in the catalog.
COMMENTS: The comment lines contain the following information, provided if available for each object:
* A line starting with "src:", identifying the discoverer or reference indicating the discovery information from the NGC. The NGC itself discusses these sources at length. Observers noted here are listed below. Archinal corrected these as necessary when the NGC was found to be in error:
d'Arrest - 28 cm (11 inch) refractor, Copenhagen.
Barnard - 15 cm (6 inch) refractor, Nashville, TN.
Bigourdan - 31 cm (12 inch) refractor, Paris, France.
Bond, G.P. Bond - 38 cm (15 inch), Harvard College Observatory, Cambridge, Mass.
S. Coolidge - see Bond.
DUN - Dunlop. 23 cm (9 inch) f/12 Newtonian.
H. - William Herschel 46.4 cm (18.25 inch), 6.1 meter (20 foot) focal length speculum mirror Newtonian/Herschelian reflector, England.
h. - John Herschel 46.4 cm (18.25 inch), 6.1 meter (20 foot) focal length speculum mirror Newtonian/Herschelian reflector, England and South Africa.
C H - Caroline Herschel.
L - F.P. Leavenworth; see O St.
Lal - Lalande.
M - Messier.
P - C.H.F. Peters.
Ld R, Ld R* - The two earls of Rosse, 91 cm (36 inch) and 183 cm (72 inch) speculum metal reflectors. Birr Castle, Ireland.
J.H. Safford - See Bond.
O St - Ormond Stone. Clark 66 cm (26 inch) refractor, University of Virginia, Charlottesville, VA. (still in operation!)
Struve - O. Struve
T - Tempel.
* A line starting with "ngc:", giving the original "OLD" description, as it appears in the RNGC. The abbreviations used follow a system first established by William Herschel, and subsequently used (with some changes) by many other observers as well as in the GC [Herschel, 1863], NGC and RNGC. See the NGC introduction for more detail.
* A line starting with "pss:", giving RNGC "NEW" description. These are mostly entries by Sulentic after examining the appropriate Palomar Observatory Sky Survey (POSS or PSS) ) O print. In many cases a POSS description is not actually given, but rather a reference to earlier investigators. Some of the abbreviations used in this description follow:
CL - cluster
COLLINDER - Collinder [1931]
DC (type 7) - D. Carlson [1940]
DESCRIP - description
EL - elongated
GRP - group
KN - knot
NEB - nebula
NF - not found
NO CL, NOCL - no cluster
NUC - nucleus
LINDSAY - E. Lindsay [1963, 1964]
R (type 7) - Alter, et. al [1970]
S - spiral
S (type 7) - J.W. Sulentic
SEV - several
STEL - stellar
ZWICKY - F. Zwicky [1961-1968]
* - star
** - double star
*** - triple star
= - same object as
xxxx - (1 to 4 digit number) RNGC object
) - means "?" or "not sure"
* A line starting with "arc:", giving Archinal's "True" desription, indicating what the object really is, as indicated by the monograph notes or derived entirely from the RNGC data. A question mark follows all entries where some question exists (particularly where the question is whether a star group is a true cluster or not) or the RNGC data should still be confirmed. A double question mark indicates the information given is derived entirely from the RNGC data. If known, the object size in arc minutes, the number of stars (n*), their magnitudes (including the brightest star first), and the total magnitude are given. Magnitudes are visual or approximate unless otherwise indicated. For objects now known to be galaxies, the size and total magnitude are given if available. Abbreviations used by Archinal include:
cent. - central part of
cl - a cluster of stars, physically associated
cl? - a cluster of stars, likely physically associated
galaxy - a galaxy
globular - globular star cluster
grp - group of stars, not a true cluster
grp? - group of stars, likely not a true cluster
grps? - groups of stars or Milky Way patches
HII - H II region
LMC - Large Magellanic Cloud
MW - Milky Way star cloud
=Mxx - is the same as Messier xx
=Nxxxx - is the same as NGC xxxx
nebula? - a "nebulous" object
no obj. - no object can be found matching this entry
* A line starting with "status:", giving the present status of knowledge about a given entry and whether further observations are needed or possible. A "NO" indicates that the object truly does not exist or is equal in identity to some other object. An "OK" indicates the identity of the object has been determined and it is observable. A "YES" indicates that there is still some uncertainty in the identity or description of the object, or else observation or examination of photographs is still needed. As indicated above, the number of objects in these catagories is 6(NO), 99(OK) and 124(YES).