Licence and notices
Copyright (C) 2026 Laurence Horrocks-Barlow.
Valerian is free software under the GNU General Public Licence, version 3 or (at your option) any later version, with the additional terms below. The Valerian logo is not part of that licence. Back to the main site: 12hobbies.studio.
Additional terms under section 7 of the GNU General Public License version 3
Valerian is licensed under the GNU General Public License, version 3 or (at your option) any later version (see LICENSE). As permitted by section 7(b) and section 7(c) of that licence, the following additional terms apply to Valerian and to every work based on it.
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Author attribution and dedication must be preserved. The author attribution
Copyright (C) 2026 Laurence Horrocks-Barlow
and the dedication of Valerian, which forms part of that author attribution,
Valerian is dedicated to my son Xaviar. His middle name is Valerian, because he was a very sleepy child, which suits software made for the long, quiet hours of the night sky.
must be preserved, unaltered, in the source code notices and in the Appropriate Legal Notices displayed by the program (its About page and its version output).
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No misrepresentation of origin. Modified versions must be marked as changed from the original, and must not be presented as the original work or as made or endorsed by Laurence Horrocks-Barlow.
These terms are not "further restrictions" within the meaning of section 7 of the licence; they travel with the work and with every copy and modification of it.
Valerian logo licence
Copyright (C) 2026 Laurence Horrocks-Barlow. All rights reserved.
The Valerian source code is free software under the GPL-3.0-or-later with the
additional terms in ADDITIONAL-TERMS.md. The Valerian
logo is not part of that. The logo, and every image derived from it, is not
covered by the GPL. In the REUSE sense it is LicenseRef-Valerian-Logo (the text
is in LICENSES/LicenseRef-Valerian-Logo.txt).
What is covered
Everything under assets/branding/:
| File | What it is |
|---|---|
valerian-logo.png | The original artwork, unmodified. |
icons/valerian-*.png, valerian.ico, valerian.icns | The same artwork resized, unchanged otherwise, for the application icon, the installers and the packages. |
And two derived uses, which stay with the logo:
| File | What it is |
|---|---|
docs/book/src/images/valerian-logo.png | The galaxy part of the artwork, cropped and resized, for the header of the manual. |
The top bar of valerian-gui | The same crop, drawn from the embedded 128 pixel icon, which also appears in the screenshots in the manual . |
The original is identified by its SHA-256:
17c9c3a860119c912b4be2df7b325fd8e6e7366ba607a6747c415d538fcd4e7c valerian-logo.png
What you may do
- Use the logo, unmodified, in unmodified builds of Valerian, such as the releases published by the author.
- Use the unmodified logo to refer to the Valerian project: an article, a review, a link to the project page.
Anything else needs the author's written permission.
Forks and modified versions
If you distribute a modified version of Valerian, or a fork, you must replace the logo and every image derived from it with your own, so that your version is not mistaken for the original. This goes with ADDITIONAL-TERMS.md (GPLv3 section 7(c)): a modified version must not be presented as the original work or as made or endorsed by Laurence Horrocks-Barlow.
Star catalogue: Gaia DR3
Valerian ships a star catalogue, gaia-dr3-g11.vcat (star positions and G magnitudes
down to G = 11), built from Gaia Data Release 3. It is data read by valerian solve and
valerian photocal, not part of the program's code.
- Source: Gaia Collaboration, "Gaia Data Release 3", Astronomy and Astrophysics 674, A1 (2023), https://www.cosmos.esa.int/gaia. This work has made use of data from the European Space Agency (ESA) mission Gaia, processed by the Gaia Data Processing and Analysis Consortium (DPAC).
- Copyright: ESA/Gaia/DPAC.
- Licence: Creative Commons Attribution-ShareAlike 3.0 IGO (CC BY-SA 3.0 IGO), https://creativecommons.org/licenses/by-sa/3.0/igo/. Any copy or adaptation of the catalogue file must carry the same licence and this attribution. The file is data and is licensed separately from the GPL program code.