The sources, datasets, and tools the lab leans on.
We do not produce primary observational data. Everything we publish is a synthesis or calibration against the work of others. This page lists what we cite, organised by category, with direct links where the source is publicly accessible.
Items are alphabetised within section by first author or institutional name. If you spot a missing reference that should be here, write to contact@loklab.org.
Ephemerides and reference frames
The numerical backbone of every reconstruction the lab publishes. Each computation we do calls one of these and we identify which in the methodology header of every post.
JPL Development Ephemeris DE441 (Park et al., AJ 2021).
Planetary positions and velocities, 1550-2650, used for all our calculations beyond the lunar/Moon work.
Swiss Ephemeris (Astrodienst). [link]
Our software interface to DE441; provides convenient time-standard conversions and historical Julian/Gregorian handling.
IAU 2006 precession-nutation model (Capitaine, Wallace & Chapront, A&A 2003-2008 series).
Standard for moving between ICRF and date-of-observation coordinates.
ICRF3 (Charlot et al., A&A 2020).
The third realisation of the International Celestial Reference Frame, anchored on 4,536 extragalactic radio sources.
IERS Earth Orientation Parameters (IERS Bulletin A). [link]
ΔT, UT1-UTC, polar motion, leap seconds. Continuously updated.
Stephenson & Morrison, Phil. Trans. R. Soc. A, 2016.
Historical ΔT compilation used for all reconstructions before 1955.
Stellar and galactic surveys
Catalogue-grade datasets we cite in cosmic-pattern, Milky Way, and distance-ladder work.
Gaia Data Release 3 (Gaia Collaboration, A&A 2023). [link]
1.8 billion stars with astrometric, photometric, and spectroscopic data. The single most-cited dataset on this site.
Hipparcos Catalogue (ESA, 1997).
Predecessor to Gaia, still used for very-bright-star astrometry and pre-Gaia reductions.
Sloan Digital Sky Survey, DR18 (Almeida et al., ApJS 2023). [link]
Large-scale structure mapping, cosmic-web context, galaxy redshift surveys.
Cosmicflows-3 (Tully, Courtois, Sorce, AJ 2016).
The peculiar-velocity survey used to define the Laniakea Supercluster.
NASA Extragalactic Database (NED). [link]
Galaxy catalogue and cross-identifications.
SIMBAD astronomical database (CDS Strasbourg). [link]
Stellar identifications and bibliographic lookups for every named object in our reconstructions.
Cosmology
Standard references for cosmic-scale claims and the parameters of the current cosmological model.
Planck Collaboration, A&A 2020 (final results).
Cosmological parameters including H₀, Ωₘ, ΩΛ, and the age of the universe (13.787 ± 0.020 Gyr).
Pantheon+ supernova compilation (Scolnic et al., ApJ 2022).
Type Ia distance-modulus database used in low-redshift Hubble-constant determinations.
Riess et al., SH0ES collaboration papers, ApJ 2016-2024.
Local distance-ladder Hubble constant determinations.
Tully, Courtois, Hoffman, Pomarède, Nature 2014.
Definition of the Laniakea Supercluster.
Exoplanets
NASA Exoplanet Archive (continuously updated). [link]
Our reference for all exoplanet count and parameter claims.
Borucki et al., ApJ 2010 (Kepler mission overview).
Ricker et al., JATIS 2015 (TESS mission).
Mayor & Queloz, Nature 1995.
First exoplanet around a sun-like star (51 Peg b).
Wolszczan & Frail, Nature 1992.
First confirmed exoplanets (pulsar planets).
Eclipses and historical reconstructions
NASA/GSFC Five Millennium Canon of Solar Eclipses (Espenak & Meeus). [link]
Definitive reference for solar-eclipse circumstances from −1999 to +3000.
Meeus, Astronomical Algorithms, 2nd ed. (Willmann-Bell, 1998).
Standard reference for the algorithms underlying most ephemeris computations.
Dyson, Eddington, Davidson, Phil. Trans. R. Soc. 1920.
The Príncipe and Sobral 1919 eclipse measurements that confirmed general relativity.
Galileo, Sidereus Nuncius (1610).
Primary source for the January 1610 Jupiter-moon observations.
Comets
JPL Small-Body Database (Horizons system). [link]
Orbital elements for every numbered and unnumbered comet and asteroid.
Yeomans, Comets: A Chronological History (Wiley, 1991).
Standard reference for historical comet apparitions.
Reinhard, Schwehm, Battrick, eds., The Giotto Mission (ESA SP-1077).
Primary scientific results from the 1986 Halley flyby.
Tools and software
Astropy (Astropy Collaboration, A&A 2022). [link]
Python astronomical computing library; used in our pipeline for unit handling and coordinate transformations.
Skyfield (Brandon Rhodes). [link]
Pure-Python ephemeris library; used for sanity-checking cross-implementation results.
Stellarium. [link]
Open-source planetarium; used for visual cross-checks of historical sky reconstructions.
History of astronomy
Neugebauer, A History of Ancient Mathematical Astronomy (Springer, 1975).
The standard scholarly reference for Babylonian and early Greek mathematical astronomy.
Sachs & Hunger, Astronomical Diaries and Related Texts from Babylonia (Austrian Academy of Sciences, 1988 onward).
Critical edition of the Babylonian Astronomical Diaries, ~747 BCE through the Seleucid era.
Pingree, From Astral Omens to Astrology, From Babylon to Bīkāner (Istituto Italiano per l'Africa e l'Oriente, 1997).
Scholarly history of pre-Hellenistic mathematical astronomy traditions and their philological dating.
Reiner & Pingree, Babylonian Planetary Omens (Brill, multiple volumes, 1975 onward).
Critical edition of the Enuma Anu Enlil (approximately 7,000 omens across 68 to 70 tablets).
Needham, Science and Civilisation in China, Vol. 3 (Cambridge, 1959).
Comprehensive history of Chinese astronomical records, including the 1054 supernova and comet catalogues.
Witzel, in Klostermaier ed., A Survey of Hinduism (SUNY, 1989) and subsequent papers on Vedic chronology.
Mainstream philological framework for dating Vedic texts.
Subbarayappa, The Tradition of Astronomy in India: Jyotihśāstra (Pearson Longman, 2008).
Surya Siddhanta and the Indian astronomical tradition in scholarly framing.
Hartner, Copernicus, the Man, the Work, and Its History, Proc. American Philosophical Soc. 117 (1973): 413-422.
The paper that first identified al-Tusi's Arabic letter labels in Copernicus's De revolutionibus.
Saliba, Islamic Science and the Making of the European Renaissance (MIT, 2007).
How the work of al-Battani, al-Tusi, ibn al-Shatir, and others reached Copernicus.
The bibliography is updated as the lab publishes. Versions are timestamped in the public changelog of the repository. Where a primary reference is paywalled, we cite the preprint if one exists.