Description

The star maps below give a graphical representation of Flamsteed's catalog, one constellation at a time, illustrating some of the features of the catalog described on the previous page. They use the equatorial coordinate system corresponding to the catalog's equinox January 1st 1690 (old style), or Julian Day 2,338,331.

Ordinary stars from Flamsteed's catalog are represented at the positions given by Flamsteed by blue disks. The bright stars from the Yale Bright Star Catalogue and less bright stars associated to Flamsteed stars are represented by black crosses at the positions given by the Hipparcos Catalogue, adjusted to the epoch 1690 according to their proper motion and precessed to the equinox 1690. Each Flamsteed star is linked to its corresponding cross, if any, by a line segment. Flamsteed's positions are so accurate that the line segment is often invisible and the cross falls almost exactly at the center of the circle.

The radius of the disk is proportional to the magnitude assigned to the star by Flamsteed. For magnitudes given as a range, I have used an interpolated value according to the common convention which translates the range 3-4 to the value 3.33 and 4-3 to 3.66, for instance. For some stars, the magnitude is replaced by the abbreviation tel (telescopic), neb (nebulous), obs (obscure), or completely absent. I have assigned arbitrary magnitude values to these special star types according to the following table and given a dotted border to nebulous stars.

MagnitudeAssigned valueCases
none6.0(10 cases)
obs7.07 Cap, 10 Cap, 12 Cap
tel8.07 Ari
neb4.033 And, 55 And

The maps also represent as red disks the positions corrected or supplied by F. Baily in his updated version of the British Catalogue, as explained on the previous page. These corrections bring all the existing stars of the catalog in pretty good agreement with their modern positions.

Modern constellation boundaries precessed to the equinox 1690 are represented for reference. Flamsteed designations are given (in blue, or red if the position has been corrected) for the stars of the constellation under consideration and stars from neighboring constellations that fall within its modern boundary. The label includes the constellation abbreviation when it doesn't match the modern constellation corresponding to the star's position.

With these conventions in place, all the Flamsteed stars appear on the maps except 5 Cyg and 38 Cyg which remain without position even after applying the corrections (they are listed as non-existent anyway). The other non-existent stars appear as lonely disks. The wildly erroneous position of 33 Com from Flamsteed's catalog is not represented. Duplicate entries are recognizable by their double labels on the map corresponding to their actual constellation.

Maps

The maps are arranged in the same order as the constellations in Flamsteed's catalog. Maps covering Microscopium and Scutum have been added because they contain stars respectively assigned by Flamsteed to Piscis Austrinus and Aquila that would not be visible on any other map.

Aries
ARI
Taurus
TAU
Gemini
GEM
Cancer
CNC
Leo
LEO
Virgo
VIR
Libra
LIB
Scorpius
SCO
Sagittarius
SGR
Capricornus
CAP
Aquarius
AQR
Pisces
PSC
Cetus
CET
Eridanus (N)
ERI_N
Orion
ORI
Lepus
LEP
Monoceros
MON
Canis Major
CMA
Canis Minor
CMI
Puppis
PUP
Hydra (W)
HYA_W
Crater
CRT
Hydra (E)
HYA_E
Corvus
CRV
Sextans
SEX
Centaurus
CEN
Lupus
LUP
Piscis Austrinus
PSA
PsA (in Mic)
MIC
Cassiopeia
CAS
Andromeda
AND
Triangulum
TRI
Perseus
PER
Camelopardalis
CAM
Auriga
AUR
Lynx
LYN
Leo Minor
LMI
Ursa Major
UMA
Draco
DRA
Coma Berenices
COM
Canes Venatici
CVN
Bo├Âtes
BOO
Corona Borealis
CRB
Ursa Minor
UMI
Hercules
HER
Serpens Caput
SER1
Serpens Cauda
SER2
Ophiuchus
OPH
Lyra
LYR
Aquila
AQL
Aquila (in Sct)
SCT
Sagitta
SGE
Vulpecula
VUL
Cygnus
CYG
Delphinus
DEL
Equuleus
EQU
Pegasus
PEG
Lacerta
LAC
Cepheus
CEP

The maps are framed around the modern constellation boundaries exactly like these reference maps in order to facilitate the comparison. The Flamsteed map and the corresponding reference map can be superposed on the monitor, and flipping from one to the other reveals the modern star designations and star names, the precession of the coordinate systems from Flamsteed's epoch to J2000.0, and even the change of position of stars with high proper motion.


Acknowledgments.

  • This research has made use of the VizieR catalogue access tool, CDS, Strasbourg, France. The original description of the VizieR service was published in A&AS 143, 23.
  • This research has made use of the SIMBAD database, operated at CDS, Strasbourg, France.