XALEN Ephemeris
Copyright 2024-2026 XALEN Technology Pvt Ltd

This product includes software developed at
XALEN Technology Pvt Ltd (https://vedika.io).

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

    http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.

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Third-Party Acknowledgments:

- VSOP87 planetary theory: P. Bretagnon, G. Francou (1987), Bureau des Longitudes
- ELP2000-82 lunar theory: M. Chapront-Touze, J. Chapront (1982), Bureau des Longitudes
- Pluto analytical theory: J. Meeus, based on Goffin/Steyaert fit to JPL DE200
- DE440 ephemeris data: NASA/JPL (Jet Propulsion Laboratory)
- IAU 2006 precession: N. Capitaine, P.T. Wallace, J. Chapront (2003)
- IAU 2000B nutation: D.D. McCarthy, G. Petit (IERS TN 32)
- Delta-T model: F.R. Stephenson, L.V. Morrison, C.Y. Hohenkerk (2016)
- Fixed-star catalog: The Hipparcos and Tycho Catalogues, (C) ESA 1997
  (ESA SP-1200), distributed by CDS Strasbourg as catalogue I/239. The
  expanded fixed-star catalog (Vmag <= 6.5) is generated directly from
  I/239 hip_main.dat (positions, magnitudes, proper motions).
- Fixed-star traditional names: IAU Catalog of Star Names (IAU-CSN),
  IAU Division C Working Group on Star Names (WGSN), used under
  Creative Commons Attribution; names carried onto HIP identifiers.
- Star identities additionally cross-checked against the CDS/SIMBAD
  Astronomical Database, Strasbourg.
- I-Ching (Yi King) text: James Legge, Sacred Books of the East Vol. XVI (1882), public domain.

NOTE ON COMMERCIAL SCOPE: A 'comprehensive' COMMERCIAL claim over the
Hipparcos-derived catalog still requires CDS/ESA license clearance for
redistribution. This release ships under the attribution above; the
clearance gate is tracked in docs and is NOT yet resolved.

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ERFA (Essential Routines for Fundamental Astronomy) — BSD 3-Clause

The precession and frame-bias matrix numerics in crates/xalen-coords
(precession.rs: pfw06, fw2m, bi00, bp00, pmat06) are an independent Rust
port of the corresponding ERFA routines and are therefore additionally
distributed under the BSD 3-Clause License below.

  Copyright (C) 2013-2023, NumFOCUS Foundation.
  All rights reserved.

  Redistribution and use in source and binary forms, with or without
  modification, are permitted provided that the following conditions are met:

  1. Redistributions of source code must retain the above copyright notice,
     this list of conditions and the following disclaimer.
  2. Redistributions in binary form must reproduce the above copyright notice,
     this list of conditions and the following disclaimer in the documentation
     and/or other materials provided with the distribution.
  3. Neither the name of the Standards Of Fundamental Astronomy Board, the
     International Astronomical Union nor the names of its contributors may be
     used to endorse or promote products derived from this software without
     specific prior written permission.

  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
  AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
  LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  POSSIBILITY OF SUCH DAMAGE.

  ERFA upstream: https://github.com/liberfa/erfa

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Commercial licensing available at https://vedika.io/ephemeris