Hoshi Stars documentation

Hoshi Stars 星 — stars you can see without a telescope, as data and as sky charts

The stars you can see without a telescope, with names, colours and distances; the 88 constellations with their lines and boundaries; the Messier objects; and seven map projections to draw them on.

Install

npm install @johnmorrisdotca/hoshi-stars

Start here

• Getting startedLook up a star, find its constellation and draw a small sky chart with its lines, in a few minutes and with no dependency.

Entry points

Guides

How-to

• The starsThe 5,080 stars of the Yale Bright Star Catalogue, how to find one by name, number or brightness, what each field means, and how a star moves.
• Colour and distanceTurn a star's colour index into a temperature and a colour to draw, and its parallax into light-years.
• Constellations and their linesThe 88 constellations by name in English or Japanese, which one a point is in, their boundaries to draw, and a stick figure for each.
• A star in 3DShow a star as a slowly turning 3D ball drawn from its numbers, with its limb darkening, its colour, its measured shape where it has one and the Sun at the same scale, in the demo or in an iframe.
• A star's size, temperature and portraitWork out how hot, how big and how bright a star is, with the uncertainty of each figure, and draw it from those numbers next to the Sun.
• Constellation pictures and factsA picture of each of the 88 constellations, in light and dark, as SVG and PNG files or drawn by a function, and a table of facts for a gallery or a list.
• Sky chartsPut stars, constellation lines and boundaries on a flat chart with the seven projections, and turn a point on the chart back into a point of the sky.
• What is nearThe stars and Messier objects nearest a star, an object or a point, by angle on the sky or by distance in space, and the constellations that touch a constellation.
• Printable sheetsConnect-the-dots constellations, the constellations for your country and region, a cut-out star wheel for your latitude and a sky map for each month, on A4 or US Letter, in English and Japanese, with ready-made PDFs.
• The Sun on your birthdayThe demo's page that shows which constellation the Sun was really in on a day, such as a birthday, on a chart around it, with the days it went in and came out, and the 13 constellations its path crosses in a year.
• The constellation quizThe demo's quiz page. A chart centred on one constellation with no names on it, six names to choose from, three styles and three levels, a streak and the ones you missed, all kept in the address.
• Deep-sky sizes and picturesHow big a galaxy, cluster or nebula is on the sky, which way it lies, its outline, the pictures of the brightest ones laid at their true place and size, what is measured and what is only drawn, and how far away a galaxy is.
• Nearby stars5,565 more stars with a measured distance and its error, among them Proxima Centauri, Barnard's Star and Wolf 359, as their own import so the bright-star table stays small.
• Faint starsAbout 2.5 million more stars, to magnitude 12, from UCAC4, in sky tiles that a page loads for the part of the sky it shows. Zooming into the map, or into the whole-sky page, draws them. Only the rows UCAC4 measured itself: nothing copied from Hipparcos or Tycho. The ghosts beside bright stars are left out, and the magnitudes of the bright end are APASS DR10's.
• The sky from another starMove the stars to where they would be seen from Alpha Centauri, Sirius or any point in space, with the Sun as one of them, and draw that sky with the same charts.
• A constellation in 3DPlace the stars of a constellation in space from their parallaxes, with the range each error allows, and draw it from the side, or embed the demo's turnable 3D view.
• Sky culturesThe same stars under Western, traditional Japanese and traditional Chinese figures and names: the 88 constellations and asterisms, 昴 and 北斗七星, the Twenty-Eight Mansions, in English, Japanese, Simplified and Traditional Chinese.
• Plain HTML and a CDNDraw a sky chart on a page with no build step, from jsDelivr or unpkg, and show a star's facts from a single small import.
• The whole sky on one mapThe whole sky on a wide 2:1 map, galactic or equatorial, with lines that are cut cleanly at the seam, and the demo's page that draws all 88 constellations on it and prints it as a poster.
• Black holes301 black holes with a place on the sky, a mass and a distance with their ranges, the companion star, how each was found and the paper behind each fact: Cygnus X-1, V404 Cygni, Gaia BH1, Sagittarius A*, M87* and more.
• BundlersUse the package with Vite or webpack, and keep the bundle to the parts a chart needs.
• FrameworksDraw a chart in React, Vue, Svelte and Angular, each as one small component that writes the package's SVG.
• Near stars and their planetsThe 73 star systems within 20 light-years and the nearest and best-known stars with confirmed planets, with names in English and Japanese, a place on the sky, a distance and the source of every value.
• Names on the stars and faint constellation linesHow to put the names of the brightest stars, and the constellation figures as very faint lines, on a sky you draw yourself, with the figure under the pointer at full strength, a body that covers part of the sky, and a look you change by settings alone.
• The sky by distanceHow to show the stars and galaxies out to 10, 50, 100, 500 or 1,000 light-years, each distance band in its own colour, on the sky map and in 3D, with the things whose distance is uncertain kept apart and none placed at a guess.
• A sky chart in your pageThe sky chart of the demo in your own page: <hoshi-chart> with the family's hands, or chartSvg as one SVG string for a server, a build or a print; its attributes, its events, its sizes and the frameworks.
• TypeScript and NodeThe types the package ships, how a wrong projection or a missing star is caught, and drawing the sky on a server.
• Embed a chart in an iframePut a sky chart on a page you cannot run script on, by the address of the embed page, and what each part of the address does.
• Your own points on the chartPut your own dated points on the sky chart: an observing log, a comet's track, the stars you have seen. A time range shows only what was there when, a track joins a group in date order, a click or Enter says which point, and the data never leaves the page.
• What you can see tonightThe stars you can see from a place at a moment, with the Sun, the sky's darkness and the air taken into account: visibleStars, the twilight, the airmass and how easy each star is.
• How well a star is knownFor each star, which catalogue its position, magnitude, colour, parallax and proper motion come from, the error that catalogue states, and a grade A, B or C by a rule you can read.
• The colour and brightness of the stars (the Hertzsprung-Russell diagram)Plot the stars by colour and brightness, or by temperature and luminosity: absoluteMagnitude, starProfile, and the demo's life-of-a-star page.
• A names index for a search boxOne row for each bright star and Messier object, and a chunk for the NGC and IC objects: names in English and Japanese, designations, constellation, rank weight, an address-safe id and where to point, with lookup by id and by name.
• A digital planisphereThe star wheel on screen: drag the disc or pick a date and a time, and the horizon window of your latitude shows what is up. The rings, the geometry, the address and the limits.
• Planets and the Moon on the chartPut the Moon and the planets on the sky chart from a plain list your page passes in: each is drawn by its magnitude, the Moon with its phase, with its name in English or Japanese, a tap says which, and an optional ecliptic line shows the Sun's yearly path.
• Data filesDownload the tables as CSV or Parquet and use them in other languages.
• Serve it yourselfRun your own small HTTP query service.
• Outside data, the data doorHow to hand the package your own stars or deep-sky objects as a source with its own licence and credit, how to switch one off, and how a page shows whose data is on the screen. Non-commercial and share-alike sources are allowed from a caller, with the licence printed beside the credit.

Explanation

• Data and licencesWhere each part of the data comes from, what each licence lets an MIT package pass on, and what is deliberately left out.
• One sky, three traditions: a guide for teachersFive well-known star patterns, Orion, the Big Dipper, the Pleiades, the Summer Triangle and Scorpius, as the Western, Japanese and Chinese skies name them, with readings, the stories behind them and a link to each in the demo.

Troubleshooting & FAQ

• Troubleshooting and FAQFixes for a chart that is empty or upside down, a line across the whole chart, a missing star, a constellation that is not what a book shows, and other questions.

Upgrading

• UpgradingWhat changes between versions, and how a script written for the stars in wakusei-planets moves to this package.

• ChangelogMade from the source of @johnmorrisdotca/hoshi-stars 0.47.0.
• Every export on one pageapi.html
• The docs for language modelsllms.txt · llms-full.txt