Sources and licences
FITSORA ships a sky catalogue of 12,895 objects. It rests on other people’s work: this page names whose, under which terms, and what was changed. The images on this website are credited at the end.
In the application
The same credits are in FITSORA under Settings › Sky catalogues.
Each catalogue card names the publication the catalogue goes back to and the data FITSORA ships for it,
with its licence or terms. The section Sources, licences and acknowledgements
lists authors, release, DOI, licence, the changes made and the acknowledgements; Copy sources as text
puts all of it on the clipboard. The About window leads there with Data sources and licences.
The program’s file THIRD-PARTY.md holds the same facts.
OpenNGC
The objects of the catalogue: Messier, NGC, IC and the Caldwell, Barnard and Collinder entries of the addendum, with type, position, axes, position angle, constellation, common names and cross-references. 12,582 objects.
- Authors
- Mattia Verga, with Patrick Chevalley, Christian Dersch, Jean-Sebastien Dieu and Sebastian Godelet
- Source
- github.com/mattiaverga/OpenNGC
- Release
- v20260501, Commit
36cb178a0f69dba8bfc03a99c10512831edf1c6b - DOI
- 10.21938/y.1ejWUD_MQ6b_eDFoVbbw
- Licence
- Creative Commons Attribution-ShareAlike 4.0 International (CC BY-SA 4.0). Attribution is required, and the data file stays under CC BY-SA 4.0 wherever it is redistributed or modified. The licence covers the data file, not FITSORA’s program code, and FITSORA’s own licence does not cover the file.
- File in FITSORA
catalog_openngc.tsv.gz– names release, authors, DOI, licence and changes in its own header lines.- Changes
- Stars, double stars, duplicates (Dup) and non-existent objects (NonEx) are left out, but a Messier object is always kept (M 40 is a double star); a duplicate’s designation becomes an alias of the object it duplicates; right ascension is converted to degrees; a selection of cross-identifications is kept and written the way it is typed (C 20, Sh2-155); type codes are shown in words in the interface. All other values are used as published.
Acknowledgements, in their original wording
OpenNGC quotes these for the databases it was merged from; FITSORA passes them on, because its objects carry that data.
- NASA/IPAC Extragalactic Database (NED)
“This research has made use of the NASA/IPAC Extragalactic Database (NED) which is operated by the Jet Propulsion Laboratory, California Institute of Technology, under contract with the National Aeronautics and Space Administration.”
- HyperLEDA
“We acknowledge the usage of the HyperLeda database (http://leda.univ-lyon1.fr)”
- SIMBAD
“This research has made use of the SIMBAD database, operated at CDS, Strasbourg, France”
- HEASARC
“This research has made use of data and/or software provided by the High Energy Astrophysics Science Archive Research Center (HEASARC), which is a service of the Astrophysics Science Division at NASA/GSFC.”
- Harold Corwin
“Harold Corwin's NGC/IC Positions and Notes”
OpenNGC nebula outlines
The traced outlines of bright nebulae in the field preview: 441 rings around 182 objects, one to three per nebula (three brightness cuts of one survey picture). Same release, same authors and same licence as OpenNGC (CC BY-SA 4.0, share-alike), file catalog_outlines.tsv.gz (source).
The authors traced them in Aladin Sky Atlas, developed at CDS, Strasbourg Observatory, France, over the DSS2 colour survey. OpenNGC asks that this be acknowledged wherever its outlines are used. FITSORA does not use Aladin’s code.
Acknowledgements, in their original wording
- CDS
“This research has made use of "Aladin sky atlas" developed at CDS, Strasbourg Observatory, France”
Reference: Bonnarel, F. et al. 2000, A&AS 143, 33
FITSORA additions
Additions and German names, the author’s own work, part of FITSORA, in the same file as the Sharpless entries. Copyright © 2026 Marc Fischer.
Sky images: Digitized Sky Survey, coloured by CDS
The sky image behind the field preview is not part of FITSORA. When the view opens, the application asks the
CDS hips2fits service in Strasbourg for a cutout of the
CDS/P/DSS2/color survey and keeps it on your own computer. Beside the image it shows
the credit Aladin / CDS · DSS2 colour · © STScI/NASA, CDS · ODbL
. The screenshots of the project overview on this website contain such an
image (M 31); it is part of the screenshot, the website loads nothing from CDS.
- Survey
- DSS colored (CDS/P/DSS2/color)
- Creators
- Space Telescope Science Institute (STScI) / NASA; CDS, Strasbourg - A. Oberto, P. Fernique
- Copyright
- Digitized Sky Survey - STScI/NASA, Colored & Healpixed by CDS; HiPS copyright CNRS/Unistra
- Licence
- Open Database License (ODbL 1.0), as the survey’s HiPS properties state
- DOI
- 10.26093/cds/aladin/ht9n-7r
- References
- Lasker, B. M. et al. 1996, ASP Conf. Ser. 101, 88Boch, T. & Fernique, P. 2014, ASP Conf. Ser. 485, 277
Acknowledgements, in their original wording
- Digitized Sky Survey
“The Digitized Sky Surveys were produced at the Space Telescope Science Institute under U.S. Government grant NAG W-2166. The images of these surveys are based on photographic data obtained using the Oschin Schmidt Telescope on Palomar Mountain and the UK Schmidt Telescope. The plates were processed into the present compressed digital form with the permission of these institutions. The National Geographic Society - Palomar Observatory Sky Atlas (POSS-I) was made by the California Institute of Technology with grants from the National Geographic Society. The Second Palomar Observatory Sky Survey (POSS-II) was made by the California Institute of Technology with funds from the National Science Foundation, the National Geographic Society, the Sloan Foundation, the Samuel Oschin Foundation, and the Eastman Kodak Corporation. The Oschin Schmidt Telescope is operated by the California Institute of Technology and Palomar Observatory. The UK Schmidt Telescope was operated by the Royal Observatory Edinburgh, with funding from the UK Science and Engineering Research Council (later the UK Particle Physics and Astronomy Research Council), until 1988 June, and thereafter by the Anglo-Australian Observatory. The blue plates of the southern Sky Atlas and its Equatorial Extension (together known as the SERC-J), as well as the Equatorial Red (ER), and the Second Epoch [red] Survey (SES) were all taken with the UK Schmidt. Supplemental funding for sky-survey work at the ST ScI is provided by the European Southern Observatory.”
- CDS
“This research has made use of "Aladin sky atlas" developed at CDS, Strasbourg Observatory, France”
Not included until their terms are confirmed
The Lynds Bright Nebulae were part of the catalogue up to version 0.9.58 (1,031 entries that OpenNGC does not cross-reference). They were withdrawn on 22 October 2026: the electronic edition at CDS states no redistribution terms. The terms have been asked for from CDS; until an answer is on record, they stay out. LBN numbers that OpenNGC lists for its own objects (for example LBN 974 for M 42) stay searchable, because they are OpenNGC’s data. The following editions are not bundled for the same reason:
| Catalogue | Electronic edition | Original publication |
|---|---|---|
| Lynds Bright Nebulae (LBN) | CDS VII/9 | Lynds, B. T. 1965, ApJS 12, 163 |
| Lynds Dark Nebulae (LDN) | CDS VII/7A | Lynds, B. T. 1962, ApJS 7, 1 |
| Barnard (B) | CDS VII/220A | Barnard, E. E. 1919, ApJ 49, 1 |
| van den Bergh (vdB) | CDS VII/21 | van den Bergh, S. 1966, AJ 71, 990 |
Barnard objects that OpenNGC lists itself remain part of the catalogue; what is withheld is the complete CDS edition of all 349.
Original publications of the catalogues
Each catalogue switch in FITSORA names the publication its catalogue goes back to, as SIMBAD’s Dictionary of Nomenclature of Celestial Objects lists it. The data itself comes from the sources above, not from these publications.
- Messier (M)
- Messier, C. 1781, Connaissance des Temps pour 1784, 227
- NGC
- Dreyer, J. L. E. 1888, Mem. R. Astron. Soc. 49, 1
- IC
- Dreyer, J. L. E. 1895, Mem. R. Astron. Soc. 51, 185Dreyer, J. L. E. 1908, Mem. R. Astron. Soc. 59, 105
- Caldwell (C)
- Moore, P. 1995, Sky & Telescope 90 (6), 38
- Sharpless (Sh2)
- Sharpless, S. 1959, ApJS 4, 257
- Lynds Bright Nebulae (LBN)
- Lynds, B. T. 1965, ApJS 12, 163
- Barnard (B)
- Barnard, E. E. 1919, ApJ 49, 1Barnard, E. E. 1927, A Photographic Atlas of Selected Regions of the Milky Way (Carnegie Institution of Washington)
- Collinder (Cl)
- Collinder, P. 1931, Ann. Obs. Lund 2, 1
- Melotte (Mel)
- Melotte, P. J. 1915, Mem. R. Astron. Soc. 60, 175
- Hickson Compact Groups (HCG)
- Hickson, P. 1982, ApJ 255, 382
- ESO
- Lauberts, A. 1982, The ESO/Uppsala Survey of the ESO(B) Atlas (European Southern Observatory)
- MWSC
- Kharchenko, N. V. et al. 2013, A&A 558, A53
- PGC
- Paturel, G. et al. 1989, A&AS 80, 299
- UGC
- Nilson, P. 1973, Uppsala General Catalogue of Galaxies, Nova Acta Regiae Soc. Sci. Upsaliensis, Ser. V:A
Images and fonts of this website
- Screenshots are drawn from FITSORA itself, with a synthetic demo archive in an isolated profile. The sky image in the project overview is credited above.
- The sky picture in the page headers, the preview image of shared links and the star figure on the 404 page were generated with AI (Higgsfield, GPT Image 2.5). They are illustrations, not photographs, and show no real region of the sky.
- Fonts, served from this server: Inter (Copyright 2016 The Inter Project Authors); Space Grotesk (Copyright 2020 The Space Grotesk Project Authors); JetBrains Mono (Copyright 2020 The JetBrains Mono Project Authors) , each under the SIL Open Font License 1.1.
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