Celestial Atlas
Introduction to the NGC, IC and PGC Objects Pages On This Site
The Purpose of These Pages
References Used / Use of Those References / Image Sources and Copyright Information
History of the NGC/IC / Discoverers of the NGC/IC Objects
Introduction to the NGC/IC Objects Pages
Table Of NGC Object Pages / Table Of IC Object Pages / Table Of PGC Object Pages
Linking to Individual Objects


The Purpose Of These Pages, And Plans For Their Completion
     The discussion of deep space objects in my online text requires only a few hundred images to adequately illustrate all the topics involving such objects. But there are thousands of images which could be presented, and more are being taken every year. What should be done with old images when new ones become available, which beg to be used as replacements? Or with new images which are truly spectacular, but don't provide any better illustration than the ones already in the online text?
     The answer I have chosen is to create a set of pages listing various deep space objects according to one of the major catalogs of such objects compiled over the years -- Dreyer's New General Catalog (NGC) and Index Catalogs (IC), and Paturel's Catalog of Principal Galaxies (PGC). Those pages will be populated in stages, according to the following schedule:
     (1) Pages have been created to provide a place for every NGC and IC object, and every page has some content. For the PGC pages, this stage is still under consideration, as there are so many PGC objects, that covering all of them is impossible.
     (2) Every image already on the site which could be linked to an NGC/IC/PGC page will be linked to the appropriate page, and detailed information concerning those objects will be added to the linked pages, in addition to any information about them already on the site. This has been done for a small fraction of the images previously onsite, but should be completed by fall of 2010.
     (3) A very long-term stage will be to provide entries for every NGC and IC object, and every PGC object which appears in one of the NGC/IC object images. Since this will involve 20 to 30 thousand objects, collecting and collating the data and images required will require a considerable amount of time. Given the rate of progress so far, I estimate that it will take the best part of 10 years to complete this stage. However, references are provided below which will allow interested individuals to look up the information that I will provide on this site on their own, if the objects they are interested in have not yet been posted on this site.

References Used For This Project
     Needless to say, projects such as this collection of catalogs cannot be done by any individual, without relying on the work of others. The main references for my work are (1) The historic and modern NGC/IC data and list of NGC/IC discoverers compiled by Dr. Wolfgang Steinicke, (2) Positional and identification information from the HyperLeda database, (3) Extensive data listings from the NASA/IPAC NED database, (4) Dr. Harold Corwin's NGC/IC notes, (5) Malcolm Thomson's Corrections to the IC, and (6) in circumstances where no other information was available, the WikiSky visual database (unfortunately, WikiSky's correlation of images and data has many errors, but it does provide visual references which are not provided by the other sources). Much of the initial work on this project was based on the NGC/IC Project site, but most of the information of interest to me was obtained from the sources listed above, so I will be gradually replacing this second-hand information, and removing the links to it, as I revise individual pages.
     It should be noted that although some of the information referred to here is available on Wikipedia and similar websites, much of what is present there is basically stolen from other sites. Wikipedia is doing a better job of requiring citations and references to the original work than it used to, but whether those citations actually received permission from the original authors is often ignored. Similarly, many of the images in Wikimedia Commons, though supposedly in the public domain, have incorrect attribution, and are actually copyrighted. I have tried as much as possible to find the original source material, and to receive permission to use whatever material is not actually in the public domain, and offer my sincerest apologies to anyone whose work I have inadvertently used without receiving proper permission; and would appreciate their letting me know if such is the case, so that I may ask for permission and provide them with credit where credit is due.

Use Of Reference Material For Distances And Sizes
     Wherever possible, I have indicated the approximate distance and size of the objects included in these pages. Where extragalactic objects are concerned, I estimate distances from recessional velocities by assuming a Hubble expansion velocity of 73 km/sec/Mpc. Such distances are subject to substantial error due to peculiar (non-Hubble expansion) velocities for nearby objects, so wherever possible I have compared the results to redshift-independent distance estimates. Sizes of objects are then obtained by comparing their apparent size to their distance. If the recessional velocities of the objects were a substantial fraction of the speed of light, relativistic corrections would be required, to obtain accurate results. But because all NGC/IC objects are relatively close (a billion light years is an exceptionally large distance for objects discovered more than a century ago), such corrections are unnecessary.

Image Sources and Copyright Information
     All images on this site are either in the public domain, or are posted with the permission of the copyright holder; but as explained on my Copyright and Fair Use Page, that permission does not extend to commercial use, and even noncommercial use requires some credit to be given where credit is due (so read the Fair Use page in detail, before you consider using any of these images anywhere else). Hence many images have the original source credited, along with a link to that source. The one exception (and a major one, because of the number of images for which it applies) is that for many objects, the only images available are Wikisky "cutouts" of DSS2 or SDSS full- or part-sky photomosaics. This paragraph constitutes acknowledgement of the copyrights associated with the images Wikisky used to create those photomosaics. Which of the two photomosaics are used for a given image is shown by mousing over or clicking on an image which is otherwise uncredited. If the tag which pops up reads "Wikisky image", it is from a DSS2 photomosaic. If it reads "Wikisky SDSS image", it is from an SDSS photomosaic.

History of the New General and Index Catalogs
(INCOMPLETE DISCUSSION; for a fascinating and very thorough discussion of the history and contents of the NGC, refer to Wolfgang Steinicke's book on the subject.)
      When the New General Catalog was done, in the late 1800's and early 1900's, NGC numbers were assigned in order of right ascension, so NGC 1 had the smallest right ascension, NGC 2 the next smallest, and so on. Since then, precession has altered the positions of the Poles and the Celestial Equator by more than a degree, changing the right ascensions in different ways in different regions. As a result, objects at very different declinations may have their right ascensions slightly out of order. Objects in the same area, however, such as NGC 1 and NGC 2, still have increasing right ascension for increasing NGC numbers.
     Epoch 2000.0 positions and basic object descriptions are based on the NASA/IPAC extragalactic database (NED), or where no description is available there, on Wolfgang Steinicke's databases. Where reasonably reliable, independent physical data are not available, estimates of size and distance are also based on that database. Where high-quality public-domain images are posted, credits are listed and links are provided to the original source material. Objects for which no other images are available are taken from, as indicated by their "mouse-over" descriptions, Wikisky cutouts.
     Discovery data are taken from Wolfgang Steinicke's Historic NGC/IC databases, for which links are provided on the Discoverers page. Each observer's name is linked to an entry on that page, where additional links and biographical data links are provided.
     I should note that the descriptions in Dreyer's catalogs are brief combinations of letters, which allowed for a lot of information in a very brief format. For instance, "F, S, dif, Epf" meant "faint, small, diffuse, extended east and west". To eliminate the need for readers of these pages to learn the abbreviations, I have expanded the abbreviations to full-word descriptions. However, there is an interesting historical aspect preserved in the abbreviation. Strictly speaking, Epf means extended preceding and following, not extended east and west; but historically, observers who cataloged hundreds or thousands of objects would measure their positions by letting them slowly drift across the field of view of their telescopes, as the sky rotated. As a result of the westward rotation of the sky, objects to the west would cross the field of view at a time preceding, and objects to the east would cross the field of view at a time following, the time at which the object in question did so. This relationship between the time that objects cross the sky and their position is in fact the reason that east-west positions (right ascension) are measured in time units.

Linking to Individual Objects

     To link to individual Messier, NGC, IC or PGC objects, use the following format, where XX is the number of the object in question:


Messier Objects: http://cseligman.com/text/stars/messierpageaddress.htm#XX
NGC objects: http://cseligman.com/text/atlas/ngcpageaddress.htm#XX
IC objects: http://cseligman.com/text/atlas/icpageaddress.htm#icXX
PGC objects: http://cseligman.com/text/atlas/pgcpageaddress.htm#pgcXX

The catch-all page for PGC objects, pgcmisc.htm, uses the same format as shown above. When one of those objects is moved to a permanent location, the original pgcmisc.htm#pgcXX target will be replaced by a link to the new location.


Index to the New General Catalog, Index Catalog, and Principal Galaxies Catalog Pages

     The 265 NGC/IC pages listed in the tables below will eventually contain pictures and detailed descriptions of every NGC/IC object already shown on this site, plus any others mentioned on the constellation pages, linked to their constellation pages (and vice-versa). Each incomplete NGC page also contains a link to the corresponding NGCIC Project page, so that every NGC object can be looked up, whether posted on this site or not (Even though the NGC/IC Project pages are lifted from other material, they do represent a convenient starting place, in the absence of other data.). Every NGC/IC page has some content, but only about 2% of the nearly 13 thousand objects have any post at all, and only about half those are as fully covered as they will be, once the catalog is complete.
     See the first NGC or IC page for a reasonably complete example of what the content of these pages will look like.
     I have no intention of listing the millions of PGC objects; but every NGC/IC object, every PGC object shown in one of the NGC/IC object images, and a selection of other PGC objects will eventually be entered on the PGC pages.


New General Catalog (NGC) Objects
1-49
50-99
100-149
150-199
200-249
250-299
300-349
350-399
400-449
450-499
500-549
550-599
600-649
650-699
700-749
750-799
800-849
850-899
900-949
950-999		 1000-1049
1050-1099
1100-1149
1150-1199
1200-1249
1250-1299
1300-1349
1350-1399
1400-1449
1450-1499
1500-1549
1550-1599
1600-1649
1650-1699
1700-1749
1750-1799
1800-1849
1850-1899
1900-1949
1950-1999		 2000-2049
2050-2099
2100-2149
2150-2199
2200-2249
2250-2299
2300-2349
2350-2399
2400-2449
2450-2499
2500-2549
2550-2599
2600-2649
2650-2699
2700-2749
2750-2799
2800-2849
2850-2899
2900-2949
2950-2999		 3000-3049
3050-3099
3100-3149
3150-3199
3200-3249
3250-3299
3300-3349
3350-3399
3400-3449
3450-3499
3500-3549
3550-3599
3600-3649
3650-3699
3700-3749
3750-3799
3800-3849
3850-3899
3900-3949
3950-3999		 4000-4049
4050-4099
4100-4149
4150-4199
4200-4249
4250-4299
4300-4349
4350-4399
4400-4449
4450-4499
4500-4549
4550-4599
4600-4649
4650-4699
4700-4749
4750-4799
4800-4849
4850-4899
4900-4949
4950-4999		 5000-5049
5050-5099
5100-5149
5150-5199
5200-5249
5250-5299
5300-5349
5350-5399
5400-5449
5450-5499
5500-5549
5550-5599
5600-5649
5650-5699
5700-5749
5750-5799
5800-5849
5850-5899
5900-5949
5950-5999		 6000-6049
6050-6099
6100-6149
6150-6199
6200-6249
6250-6299
6300-6349
6350-6399
6400-6449
6450-6499
6500-6549
6550-6599
6600-6649
6650-6699
6700-6749
6750-6799
6800-6849
6850-6899
6900-6949
6950-6999		 7000-7049
7050-7099
7100-7149
7150-7199
7200-7249
7250-7299
7300-7349
7350-7399
7400-7449
7450-7499
7500-7549
7550-7599
7600-7649
7650-7699
7700-7749
7750-7799
7800-7840

Index Catalog (IC) I / II Objects
1-49
50-99
100-149
150-199
200-249
250-299
300-349
350-399
400-449
450-499
500-549
550-599
600-649
650-699
700-749
750-799
800-849
850-899
900-949
950-999		 1000-1049
1050-1099
1100-1149
1150-1199
1200-1249
1250-1299
1300-1349
1350-1399
1400-1449
1450-1499
1500-1549
1550-1599
1600-1649
1650-1699
1700-1749
1750-1799
1800-1849
1850-1899
1900-1949
1950-1999		 2000-2049
2050-2099
2100-2149
2150-2199
2200-2249
2250-2299
2300-2349
2350-2399
2400-2449
2450-2499
2500-2549
2550-2599
2600-2649
2650-2699
2700-2749
2750-2799
2800-2849
2850-2899
2900-2949
2950-2999		 3000-3049
3050-3099
3100-3149
3150-3199
3200-3249
3250-3299
3300-3349
3350-3399
3400-3449
3450-3499
3500-3549
3550-3599
3600-3649
3650-3699
3700-3749
3750-3799
3800-3849
3850-3899
3900-3949
3950-3999		 4000-4049
4050-4099
4100-4149
4150-4199
4200-4249
4250-4299
4300-4349
4350-4399
4400-4449
4450-4499
4500-4549
4550-4599
4600-4649
4650-4699
4700-4749
4750-4799
4800-4849
4850-4899
4900-4949
4950-4999		 5000-5049
5050-5099
5100-5149
5150-5199
5200-5249
5250-5299
5300-5349
5350-5386

Principal Galaxy Catalog (PGC) Objects 1 - 69999
(links to be activated as pages are added)
1-499
500-999
1000-1499
1500-1999
2000-2499
2500-2999
3000-3499
3500-3999
4000-4499
4500-4999
5000-5499
5500-5999
6000-6499
6500-6999
7000-7499
7500-7999
8000-8499
8500-8999
9000-9499
9500-9999		 10000-10499
10500-10999
11000-11499
11500-11999
12000-12499
12500-12999
13000-13499
13500-13999
14000-14499
14500-14999
15000-15499
15500-15999
16000-16499
16500-16999
17000-17499
17500-17999
18000-18499
18500-18999
19000-19499
19500-19999		 20000-20499
20500-20999
21000-21499
21500-21999
22000-22499
22500-22999
23000-23499
23500-23999
24000-24499
24500-24999
25000-25499
25500-25999
26000-26499
26500-26999
27000-27499
27500-27999
28000-28499
28500-28999
29000-29499
29500-29999		 30000-30499
30500-30999
31000-31499
31500-31999
32000-32499
32500-32999
33000-33499
33500-33999
34000-34499
34500-34999
35000-35499
35500-35999
36000-36499
36500-36999
37000-37499
37500-37999
38000-38499
38500-38999
39000-39499
39500-39999		 40000-40499
40500-40999
41000-41499
41500-41999
42000-42499
42500-42999
43000-43499
43500-43999
44000-44499
44500-44999
45000-45499
45500-45999
46000-46499
46500-46999
47000-47499
47500-47999
48000-48499
48500-48999
49000-49499
49500-49999		 50000-50499
50500-50999
51000-51499
51500-51999
52000-52499
52500-52999
53000-53499
53500-53999
54000-54499
54500-54999
55000-55499
55500-55999
56000-56499
56500-56999
57000-57499
57500-57999
58000-58499
58500-58999
59000-59499
59500-59999		 60000-60499
60500-60999
61000-61499
61500-61999
62000-62499
62500-62999
63000-63499
63500-63999
64000-64499
64500-64999
65000-65499
65500-65999
66000-66499
66500-66999
67000-67499
67500-67999
68000-68499
68500-68999
69000-69499
69500-69999

Principal Galaxy Catalog (PGC) Objects 70000 - 129999
(links to be activated as pages are added)
70000-70499
70500-70999
71000-71499
71500-71999
72000-72499
72500-72999
73000-73499
73500-73999
74000-74499
74500-74999
75000-75499
75500-75999
76000-76499
76500-76999
77000-77499
77500-77999
78000-78499
78500-78999
79000-79499
79500-79999		 80000-80499
80500-80999
81000-81499
81500-81999
82000-82499
82500-82999
83000-83499
83500-83999
84000-84499
84500-84999
85000-85499
85500-85999
86000-86499
86500-86999
87000-87499
87500-87999
88000-88499
88500-88999
89000-89499
89500-89999		 90000-90499
90500-90999
91000-91499
91500-91999
92000-92499
92500-92999
93000-93499
93500-93999
94000-94499
94500-94999
95000-95499
95500-95999
96000-96499
96500-96999
97000-97499
97500-97999
98000-98499
98500-98999
99000-99499
99500-99999		 100000-100499
100500-100999
101000-101499
101500-101999
102000-102499
102500-102999
103000-103499
103500-103999
104000-104499
104500-104999
105000-105499
105500-105999
106000-106499
106500-106999
107000-107499
107500-107999
108000-108499
108500-108999
109000-109499
109500-109999		 110000-110499
110500-110999
111000-111499
111500-111999
112000-112499
112500-112999
113000-113499
113500-113999
114000-114499
114500-114999
115000-115499
115500-115999
116000-116499
116500-116999
117000-117499
117500-117999
118000-118499
118500-118999
119000-119499
119500-119999		 120000-120499
120500-120999
121000-121499
121500-121999
122000-122499
122500-122999
123000-123499
123500-123999
124000-124499
124500-124999
125000-125499
125500-125999
126000-126499
126500-126999
127000-127499
127500-127999
128000-128499
128500-128999
129000-129499
129500-129999
PGC 130000+