# Caldwell catalogue

The Caldwell catalogue is an astronomical catalogue of 109 star clusters, nebulae, and galaxies for observation by amateur astronomers. The list was compiled by Patrick Moore as a complement to the Messier catalogue.
While the Messier catalogue is used by amateur astronomers as a list of deep-sky objects for observation, Moore noted that Messier's list was not compiled for that purpose and excluded many of the sky's brightest deep-sky objects, such as the Hyades, the Double Cluster (NGC 869 and NGC 884), and the Sculptor Galaxy (NGC 253). The Messier catalogue was actually compiled as a list of known objects that might be confused with comets. Moore also observed that since Messier compiled his list from observations in Paris, it did not include bright deep-sky objects visible in the Southern Hemisphere, such as Omega Centauri, Centaurus A, the Jewel Box, and 47 Tucanae. Moore compiled a list of 109 objects to match the commonly accepted number of Messier objects (he excluded M110), and the list was published in Sky & Telescope in December 1995.
Moore used his other surname – Caldwell – to name the list, since the initial of "Moore" is already used for the Messier catalogue. Entries in the catalogue are designated with a "C" and the catalogue number (1 to 109).
Unlike objects in the Messier catalogue, which are listed roughly in the order of discovery by Messier and his colleagues, the Caldwell catalogue is ordered by declination, with C1 being the most northerly and C109 being the most southerly, although two objects (NGC 4244 and the Hyades) are listed out of sequence. Other errors in the original list have since been corrected: it incorrectly identified the S Norma Cluster (NGC 6087) as NGC 6067 and incorrectly labelled the Lambda Centauri Cluster (IC 2944) as the Gamma Centauri Cluster.

## Reception

The Caldwell Catalogue has generated controversy in the amateur astronomy community for several reasons.
* Moore did not discover any of the objects in his catalogue which are often very well known objects and not 'neglected' as claimed by Moore.
* Its presentation as a catalogue with distinct designations, rather than a list, potentially may cause confusion amongst amateur astronomers as the 'C' Designation is not commonly used.
* The list was promoted as an extension of the Messier Catalogue, however the objects are often arbitrary with many easily viewable objects omitted while some objects not readily available to visual observers are included.
Caldwell advocates, however, see the catalogue as a useful list of some of the brightest and best known non-Messier deep-sky objects. Thus, advocates dismiss any "controversy" as being fabricated by older amateurs simply not able or willing to memorize the new designations despite every telescope database using the Caldwell IDs as the primary designation for over 25 years. NASA/Hubble also lists the 109 objects by their Caldwell number.

## Number of objects by type in the Caldwell catalogue

| Type of object | Number of objects |
| Dark nebulae | 1 |
| Galaxies | 35 |
| Globular clusters | 18 |
| Nebulae | 9 |
| Star clusters | 25 |
| Star clusters and nebulae | 6 |
| Planetary nebulae | 13 |
| Supernova remnants | 2 |
| Total | 109 |

## Caldwell objects

Open cluster  Globular cluster  Dark nebula  Diffuse nebula  Planetary nebula  Supernova remnant  Galaxy
| Caldwell number | NGC number | Common name | Image | Type | Distance (1000 ly) | Constellation | Apparent magnitude |
| C1 | NGC 188 | Polarissima Cluster | | Open Cluster | 4.8 | Cepheus | 8.1 |
| C2 | NGC 40 | Bow-Tie Nebula | | Planetary Nebula | 3.5 | Cepheus | 11 |
| C3 | NGC 4236 | | | Barred Spiral Galaxy | 7,000 | Draco | 9.7 |
| C4 | NGC 7023 | Iris Nebula | | Open Cluster and Nebula | 1.4 | Cepheus | 7 |
| C5 | IC 342 | Hidden Galaxy | | Spiral Galaxy | 10,000 | Camelopardalis | 9 |
| C6 | NGC 6543 | Cat's Eye Nebula | | Planetary Nebula | 3 | Draco | 9 |
| C7 | NGC 2403 | | | Spiral Galaxy | 14,000 | Camelopardalis | 8.4 |
| C8 | NGC 559 | | | Open Cluster | 3.7 | Cassiopeia | 9.5 |
| C9 | Sh2-155 | Cave Nebula | | Nebula | 2.8 | Cepheus | 7.7 |
| C10 | NGC 663 | | | Open Cluster | 7.2 | Cassiopeia | 7.1 |
| C11 | NGC 7635 | Bubble Nebula | | Nebula | 7.1 | Cassiopeia | 10 |
| C12 | NGC 6946 | Fireworks Galaxy | | Spiral Galaxy | 18,000 | Cepheus | 8.9 |
| C13 | NGC 457 | Owl Cluster, E.T. Cluster | | Open Cluster | - | Cassiopeia | 6.4 |
| C14 | NGC 869 & NGC 884 | Double Cluster, h & χ Persei | | Open Cluster | 7.3 | Perseus | 4 |
| C15 | NGC 6826 | Blinking Planetary | | Planetary Nebula | 2.2 | Cygnus | 10 |
| C16 | NGC 7243 | | | Open Cluster | 2.5 | Lacerta | 6.4 |
| C17 | NGC 147 | | | Dwarf Spheroidal Galaxy | 2,300 | Cassiopeia | 9.3 |
| C18 | NGC 185 | | | Dwarf Spheroidal Galaxy | 2,300 | Cassiopeia | 9.2 |
| C19 | IC 5146 | Cocoon Nebula | | Open Cluster and Nebula | 3.3 | Cygnus | 7.2 |
| C20 | NGC 7000 | North America Nebula | | Nebula | 2.6 | Cygnus | 4 |
| C21 | NGC 4449 | | | Irregular galaxy | 10,000 | Canes Venatici | 9.4 |
| C22 | NGC 7662 | Blue Snowball | | Planetary Nebula | 3.2 | Andromeda | 9 |
| C23 | NGC 891 | Silver Sliver Galaxy | | Spiral Galaxy | 31,000 | Andromeda | 10 |
| C24 | NGC 1275 | Perseus A | | Supergiant Elliptical Galaxy | 230,000 | Perseus | 11.6 |
| C25 | NGC 2419 | | | Globular Cluster | 275 | Lynx | 10.4 |
| C26 | NGC 4244 | | | Spiral Galaxy | 10,000 | Canes Venatici | 10.2 |
| C27 | NGC 6888 | Crescent Nebula | | Nebula | 4.7 | Cygnus | 7.4 |
| C28 | NGC 752 | | | Open Cluster | 1.2 | Andromeda | 5.7 |
| C29 | NGC 5005 | | | Spiral Galaxy | 69,000 | Canes Venatici | 9.8 |
| C30 | NGC 7331 | | | Spiral Galaxy | 47,000 | Pegasus | 9.5 |
| C31 | IC 405 | Flaming Star Nebula | | Nebula | 1.6 | Auriga | 13 |
| C32 | NGC 4631 | Whale Galaxy | | Barred Spiral Galaxy | 22,000 | Canes Venatici | 9.3 |
| C33 | NGC 6992 | East Veil Nebula | | Supernova Remnant | 2.5 | Cygnus | 7 |
| C34 | NGC 6960 | West Veil Nebula | | Supernova Remnant | 2.5 | Cygnus | 7 |
| C35 | NGC 4889 | Coma B | | Supergiant Elliptical Galaxy | 300,000 | Coma Berenices | 11.4 |
| C36 | NGC 4559 | | | Spiral Galaxy | 32,000 | Coma Berenices | 9.9 |
| C37 | NGC 6885 | | | Open Cluster | 1.95 | Vulpecula | 6 |
| C38 | NGC 4565 | Needle Galaxy | | Spiral Galaxy | 32,000 | Coma Berenices | 9.6 |
| C39 | NGC 2392 | Eskimo Nebula, Clown Face Nebula | | Planetary Nebula | 4 | Gemini | 10 |
| C40 | NGC 3626 | | | Lenticular Galaxy | 86,000 | Leo | 10.9 |
| C41 | Mel 25 | Hyades | | Open Cluster | 0.151 | Taurus | 0.5 |
| C42 | NGC 7006 | | | Globular Cluster | 135 | Delphinus | 10.6 |
| C43 | NGC 7814 | | | Spiral Galaxy | 49,000 | Pegasus | 10.5 |
| C44 | NGC 7479 | Superman Galaxy | | Barred Spiral Galaxy | 106,000 | Pegasus | 11 |
| C45 | NGC 5248 | | | Spiral Galaxy | 74,000 | Boötes | 10.2 |
| C46 | NGC 2261 | Hubble's Variable Nebula | | Nebula | 2.5 | Monoceros | - |
| C47 | NGC 6934 | | | Globular Cluster | 57 | Delphinus | 8.9 |
| C48 | NGC 2775 | | | Spiral Galaxy | 55,000 | Cancer | 10.3 |
| C49 | NGC 2237 | Rosette Nebula | | Nebula | 4.9 | Monoceros | 9.0 |
| C50 | NGC 2244 | Satellite Cluster | | Open Cluster | 4.9 | Monoceros | 4.8 |
| C51 | IC 1613 | | | Irregular galaxy | 2,300 | Cetus | 9.3 |
| C52 | NGC 4697 | | | Elliptical galaxy | 76,000 | Virgo | 9.3 |
| C53 | NGC 3115 | Spindle Galaxy | | Lenticular Galaxy | 22,000 | Sextans | 9.2 |
| C54 | NGC 2506 | | | Open Cluster | 10 | Monoceros | 7.6 |
| C55 | NGC 7009 | Saturn Nebula | | Planetary Nebula | 1.4 | Aquarius | 8 |
| C56 | NGC 246 | Skull Nebula | | Planetary Nebula | 1.6 | Cetus | 8 |
| C57 | NGC 6822 | Barnard's Galaxy | | Barred irregular galaxy | 2,300 | Sagittarius | 9 |
| C58 | NGC 2360 | Caroline's Cluster | | Open Cluster | 3.7 | Canis Major | 7.2 |
| C59 | NGC 3242 | Ghost of Jupiter | | Planetary Nebula | 1.4 | Hydra | 9 |
| C60 | NGC 4038 | Antennae Galaxies | | Interacting galaxy | 83,000 | Corvus | 10.7 |
| C61 | NGC 4039 | Antennae Galaxies | | Interacting galaxy | 83,000 | Corvus | 13 |
| C62 | NGC 247 | | | Spiral Galaxy | 6,800 | Cetus | 8.9 |
| C63 | NGC 7293 | Helix Nebula | | Planetary Nebula | 0.522 | Aquarius | 7.3 |
| C64 | NGC 2362 | Tau Canis Majoris Cluster | | Open Cluster and Nebula | 5.1 | Canis Major | 4.1 |
| C65 | NGC 253 | Sculptor Galaxy | | Spiral Galaxy | 9,800 | Sculptor | 7.1 |
| C66 | NGC 5694 | | | Globular Cluster | 113 | Hydra | 10.2 |
| C67 | NGC 1097 | | | Barred Spiral Galaxy | 47,000 | Fornax | 9.3 |
| C68 | NGC 6729 | R CrA Nebula | | Nebula | 0.424 | Corona Australis | - |
| C69 | NGC 6302 | Bug Nebula | | Planetary Nebula | 5.2 | Scorpius | 13 |
| C70 | NGC 300 | Sculptor Pinwheel Galaxy | | Spiral Galaxy | 3,900 | Sculptor | 9 |
| C71 | NGC 2477 | | | Open Cluster | 3.7 | Puppis | 5.8 |
| C72 | NGC 55 | String of Pearls Galaxy | | Barred Spiral Galaxy | 4,200 | Sculptor | 8 |
| C73 | NGC 1851 | | | Globular Cluster | 39.4 | Columba | 7.3 |
| C74 | NGC 3132 | Eight Burst Nebula | | Planetary Nebula | 2 | Vela | 8 |
| C75 | NGC 6124 | | | Open Cluster | 1.5 | Scorpius | 5.8 |
| C76 | NGC 6231 | | | Open Cluster and Nebula | 6 | Scorpius | 2.6 |
| C77 | NGC 5128 | Centaurus A | | Elliptical or Lenticular Galaxy | 16,000 | Centaurus | 7 |
| C78 | NGC 6541 | | | Globular Cluster | 22.3 | Corona Australis | 6.6 |
| C79 | NGC 3201 | | | Globular Cluster | 17 | Vela | 6.8 |
| C80 | NGC 5139 | Omega Centauri | | Globular Cluster | 17.3 | Centaurus | 3.7 |
| C81 | NGC 6352 | | | Globular Cluster | 18.6 | Ara | 8.2 |
| C82 | NGC 6193 | | | Open Cluster | 4.3 | Ara | 5.2 |
| C83 | NGC 4945 | | | Barred Spiral Galaxy | 17,000 | Centaurus | 9 |
| C84 | NGC 5286 | | | Globular Cluster | 36 | Centaurus | 7.6 |
| C85 | IC 2391 | Omicron Velorum Cluster | | Open Cluster | 0.5 | Vela | 2.5 |
| C86 | NGC 6397 | | | Globular Cluster | 7.5 | Ara | 5.7 |
| C87 | NGC 1261 | | | Globular Cluster | 55.5 | Horologium | 8.4 |
| C88 | NGC 5823 | | | Open Cluster | 3.4 | Circinus | 7.9 |
| C89 | NGC 6087 | S Normae Cluster | | Open Cluster | 3.3 | Norma | 5.4 |
| C90 | NGC 2867 | | | Planetary Nebula | 5.5 | Carina | 10 |
| C91 | NGC 3532 | Wishing Well Cluster | | Open Cluster | 1.6 | Carina | 3 |
| C92 | NGC 3372 | Eta Carinae Nebula | | Nebula | 7.5 | Carina | 3 |
| C93 | NGC 6752 | Great Peacock Globular | | Globular Cluster | 13 | Pavo | 5.4 |
| C94 | NGC 4755 | Jewel Box | | Open Cluster | 4.9 | Crux | 4.2 |
| C95 | NGC 6025 | | | Open Cluster | 2.5 | Triangulum Australe | 5.1 |
| C96 | NGC 2516 | Southern Beehive Cluster | | Open Cluster | 1.3 | Carina | 3.8 |
| C97 | NGC 3766 | Pearl Cluster | | Open Cluster | 5.8 | Centaurus | 5.3 |
| C98 | NGC 4609 | | | Open Cluster | 4.2 | Crux | 6.9 |
| C99 | - | Coalsack Nebula | | Dark Nebula | 0.61 | Crux | - |
| C100 | IC 2944 | Lambda Centauri Nebula | | Open Cluster and Nebula | 6 | Centaurus | 4.5 |
| C101 | NGC 6744 | | | Spiral Galaxy | 34,000 | Pavo | 9 |
| C102 | IC 2602 | Theta Car Cluster | | Open Cluster | 0.492 | Carina | 1.9 |
| C103 | NGC 2070 | Tarantula Nebula | | Open Cluster and Nebula | 170 | Dorado | 8.2 |
| C104 | NGC 362 | | | Globular Cluster | 27.7 | Tucana | 6.6 |
| C105 | NGC 4833 | | | Globular Cluster | 19.6 | Musca | 7.4 |
| C106 | NGC 104 | 47 Tucanae | | Globular Cluster | 14.7 | Tucana | 4 |
| C107 | NGC 6101 | | | Globular Cluster | 49.9 | Apus | 9.3 |
| C108 | NGC 4372 | | | Globular Cluster | 18.9 | Musca | 7.8 |
| C109 | NGC 3195 | | | Planetary Nebula | 5.4 | Chamaeleon | 11.6 |
| Caldwell number | NGC number | Common name | Image | Object type | Distance to object in thousands of light years | Constellation | Apparent magnitude |
* ↑ C89 was mistakenly written as NGC 6067 in the original, but its description is that of NGC 6087.