Lumara open data.

Published September 4, 2026 · Updated September 4, 2026

The numbers behind this site as plain JSON files, free to fetch, free to reuse. The same daily job that rewrites the guide pages writes these. Two of them are archives that grow one complete UTC day at a time and never rewrite a published value. The rest are regenerated in full and only change when the content does. Every file starts with a meta object naming its source, its license, and the date it last changed.

What files are there?

File	What it holds	Changes
`kp-3-hourly.json`	Planetary Kp at 3-hour cadence with the running A index, from NOAA SWPC. Archive, starts late August 2026.	Daily, appends yesterday
`flares.json`	Every GOES X-ray flare of C1.0 or greater: begin, peak, end, class, peak flux, satellite. Archive, starts late August 2026.	Daily, appends ended events
`sunspots-monthly.json`	Solar Cycle 25 monthly sunspot number, 13-month smoothed number, F10.7 flux since December 2019, plus the NOAA prediction to the cycle's end.	Monthly, when NOAA posts
`moon-phases-2026.json` to `-2030.json`	Every new moon, first quarter, full moon, last quarter, UTC to the minute. One file per year.	Fixed
`lunar-apsides.json`	Every lunar perigee and apogee 2026 to 2030 with distance in km.	Fixed
`earth-apsides.json`	Earth's perihelion and aphelion 2026 to 2030 with distance in km.	Fixed
`seasons.json`	Equinoxes and solstices 2026 to 2030, UTC to the minute.	Fixed
`eclipses-2027-2030.json`	All 20 solar and lunar eclipses 2027 to 2030: greatest eclipse UTC, magnitude, durations, path, visibility. Hand-compiled from the NASA catalogs, checked against EclipseWise.	Fixed

What does a file look like?

Each file is one JSON object. meta carries the title, description, source URL, license, attribution line, and updated date. The records sit in data (or observed and predicted for the sunspot file). Times are ISO 8601 in UTC. Distances are kilometres, center to center, rounded to 10 km.

{
 "meta": {
  "title": "Equinoxes and solstices 2026 to 2030 (UTC)",
  "source": "astronomy-engine ...",
  "license": "https://creativecommons.org/licenses/by/4.0/",
  "updated": "2026-09-04"
 },
 "data": [
  { "year": 2026, "event": "March equinox", "time": "2026-03-20T14:45Z" },
  { "year": 2026, "event": "June solstice", "time": "2026-06-21T08:25Z" }
 ]
}

How do I fetch one?

Any HTTP client works, and the files allow cross-origin requests, so a browser page on another site can fetch them directly. There is no key, no rate limit beyond ordinary politeness, and no tracking. Files are cached at the edge for up to an hour.

curl https://lumara-space.app/data/kp-3-hourly.json

fetch('https://lumara-space.app/data/seasons.json')
  .then(r => r.json())
  .then(d => console.log(d.data[0]));

Where do the numbers come from?

Kp, flares, and sunspot numbers are NOAA Space Weather Prediction Center products, republished as they were fetched. The sunspot number itself is the international number from SILSO at the Royal Observatory of Belgium. Moon phases, perigee and apogee, perihelion and aphelion, and the season instants are computed with the Astronomy Engine ephemeris library and were checked against Fred Espenak's catalogs at astropixels.com and the US Naval Observatory; the checks are described on the about page and on each guide page that uses the numbers.

What is the license?

Creative Commons Attribution 4.0. Use the files for anything, including commercial work, and credit "Lumara, lumara-space.app" with a link where practical. The underlying NOAA data is US government work in the public domain; the license covers the compilation, the archive, and the computed tables.

Can the archives change after publication?

A value published in an archive file is not rewritten. Kp rows are added only for complete UTC days, and flares only after the event has ended and its day is over, so nothing provisional enters the file. If NOAA later revises a value, the archive keeps what was published and the change is noted here. If a source feed is down on a given morning, the run skips that file and picks up the missing day from the 7-day feed the next morning, so single-day outages leave no gap.

See the sunspot data as a chart