stars.gripe

Sources and licences for the star map. Back to the map.

Stars

The Yale Bright Star Catalogue, 5th revised edition (Hoffleit and Warren, 1991; CDS catalogue V/50), as distributed by NASA's HEASARC (table bsc5p). It is a public-domain US Government data product. stars.gripe uses the 9,096 entries that are stars (the 14 novae and non-stellar objects are left out): J2000 positions, proper motions, visual magnitudes, B−V colours, spectral types, trigonometric parallaxes and Bayer/Flamsteed designations. Positions are moved to the date shown for proper motion and precession (IAU 1976). Distances come from the catalogue's pre-Hipparcos parallaxes and are rough beyond a few hundred light years.

Star names

The IAU Catalog of Star Names maintained by the IAU Working Group on Star Names (WGSN), as published at iau.org. 331 of its names belong to stars in the Bright Star Catalogue.

Constellations

Constellation names, label positions, stick figures and boundaries come from d3-celestial by Olaf Frohn (BSD 3-Clause licence, below). The boundaries are the IAU's (Delporte, 1930), from Davenhall and Leggett's digitisation; stars.gripe takes them back to their 1875 equinox, where each edge is a line of constant right ascension or declination, and precesses them to the date. The English meanings of the names are ours.

Copyright (c) 2015, Olaf Frohn
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 copyright holder 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.

Sun, Moon and planets

Astronomy Engine 2.1.19 by Don Cross (MIT licence; the full notice is at the top of /vendor/astronomy.js). It also finds rise, transit and set times and twilight. Our tests check it against NASA JPL Horizons and against worked examples in Meeus's Astronomical Algorithms: the planets agree with Horizons to within half an arcminute.

Compass correction

The World Magnetic Model 2025 (NOAA's National Centers for Environmental Information and the British Geological Survey), public domain, turns the phone's magnetic heading into a true one.

Cities

The city list is our own (city centres, rounded).

Milky Way

We didn't find a traced Milky Way outline under a licence we could use, so the "Milky Way (rough)" option draws a soft band along the galactic plane, brighter toward the centre in Sagittarius. It shows where the Milky Way runs, not its shape.