29:null 2a:["$","title",null,{"children":"Star map — Mars ephemeris (2022 and following years) | Christophe Yamahata | Observable"}] 2f:T1c92,chart = { const svg = d3.create("svg") .attr("viewBox", [0, 0, width, height]) .attr("width", Math.min(width,Math.max(document.documentElement.clientWidth || 0, window.innerWidth || 0)-10) ) .attr("max-width", "600px") .attr("font-family", "sans-serif") .attr("font-size", 16) .attr("text-anchor", "middle") .attr("fill", "textColor") .style("margin", "0 -5px") .style("display", "block"); svg.append("clipPath") // define a clip path .attr("id", "disk-clip") // clipPath an ID .append("circle") .attr('cx', width/2) .attr('cy', height/2) .attr('r',width/2-60); svg.append("circle") .attr('cx', width/2) .attr('cy', height/2) .attr('r',width/2) .attr("fill", darkGrey) .attr("fill-opacity", 0.2); svg.append("path") .attr("d", path(horizon)) .attr("fill", darkSky); if(visible.includes("celestial_poles")) { // North celestial pole let polaris = svg.append("circle") .attr("r", 4.2) .attr("fill", "darkblue") .attr("stroke", asterismColor) .attr("fill-opacity", 0.4) .attr("transform", d => { let coords = [0, 90]; let projectedCoords = projection(invertAzimuth(equatorial2horizontal(julianCentury(date), λo, φo)(coords))); return `translate(${projectedCoords})` }) // South celestial pole let south_celestial_pole = svg.append("circle") .attr("r", 4.2) .attr("fill", "darkblue") .attr("stroke", asterismColor) .attr("fill-opacity", 0.4) .attr("transform", d => { let coords = [0, -90]; let projectedCoords = projection(invertAzimuth(equatorial2horizontal(julianCentury(date), λo, φo)(coords))); return `translate(${projectedCoords})` }) } // Big dipper asterism let asterismPath = svg.append("path") .attr("clip-path", "url(#disk-clip)") .attr("fill", "none") .attr("stroke", asterismColor) .attr("stroke-opacity", 0.6); // Crux let southernCross1 = svg.append("path") .attr("clip-path", "url(#disk-clip)") .attr("fill", "none") .attr("stroke", asterismColor) .attr("stroke-opacity", 0.9); let southernCross2 = svg.append("path") .attr("clip-path", "url(#disk-clip)") .attr("fill", "none") .attr("stroke", asterismColor) .attr("stroke-opacity", 0.9); if(visible.includes("graticule")) { svg.append("path") .attr("d", path(graticule)) .attr("fill", "none") .attr("stroke", lightGrey) .attr("stroke-opacity", 0.25); } let eclipticPath = svg.append("path") .attr("clip-path", "url(#disk-clip)") .attr("fill", "none") .attr("stroke", eclipticColor) .attr("stroke-dasharray", "2,4") .attr("stroke-opacity", 0.4); let MarsPath = svg.append("path") .attr("clip-path", "url(#disk-clip)") .attr("fill", "none") .attr("stroke", eclipticColor) .attr("stroke-opacity", 0.6); let MarsPos = svg.append("circle") .attr("r", planetRadius) .attr("fill", planetColor); // The equator doesn’t change (much), so just render it once. const equator = circle_ .map(equatorial2horizontal(julianCentury(date), λo, φo)) .map(invertAzimuth); if(visible.includes("equator")) { let equatorPath = svg.append("path") .attr("clip-path", "url(#disk-clip)") .attr("fill", "none") .attr("stroke", equatorColor) .attr("stroke-opacity", 0.8) .attr("d", path({type: "LineString", coordinates: equator})); }; let planetSVG = svg.append("g") .attr("clip-path", "url(#disk-clip)") .selectAll("g"); let starSVG = svg.append("g") .selectAll("g"); svg.append("g") .call(xAxis); if(visible.includes("graticule")) { svg.append("g") .call(yAxis) .attr("fill", lightGrey) .attr("fill-opacity", 0.7); } return Object.assign(svg.node(), { update(date) { const T = julianCentury(date); starSVG = starSVG.data(stars) .join( enter => enter.append("g") .call(g => g.append("circle") .attr("r", d => d.radius) .attr("fill", starColor)), update => update, exit => exit.remove() ) .attr("transform", d => { let coords = [d.ra, d.dec]; let projectedCoords = projection(invertAzimuth(equatorial2horizontal(T, λo, φo)(coords))); return `translate(${projectedCoords})` }) // Compute the ecliptic. Note: D3 will apply adaptive resampling! if(visible.includes("ecliptic")) { let ecliptic = circle_ .map(ecliptic2equatorial(T)) .map(equatorial2horizontal(T, λo, φo)) .map(invertAzimuth); eclipticPath .attr("d", path({type: "LineString", coordinates: ecliptic})); }; // Compute the orbit of Mars if(visible.includes("planetPath")) { let Mars_orbit = Mars_path_RA_Dec .map(equatorial2horizontal(T, λo, φo)) .map(invertAzimuth); MarsPath .attr("d", path({type: "LineString", coordinates: Mars_orbit})); } if(visible.includes("celestial_poles")) { // Big dipper asterism let asterism = big_dipper .map(equatorial2horizontal(T, λo, φo)) .map(invertAzimuth); asterismPath.attr("d", path({type: "LineString", coordinates: asterism})); // Crux let Crux_constellation1 = crux1 .map(equatorial2horizontal(T, λo, φo)) .map(invertAzimuth); southernCross1.attr("d", path({type: "LineString", coordinates: Crux_constellation1})); let Crux_constellation2 = crux2 .map(equatorial2horizontal(T, λo, φo)) .map(invertAzimuth); southernCross2.attr("d", path({type: "LineString", coordinates: Crux_constellation2})); } // Compute the planetary positions. Note: azimuth is already North-oriented! const planets = Object.entries(ephemeris.getAllPlanets(dateHour, λo, φo, 0).observed) .map(([name, {raw: {position: {altaz: {topocentric: {altitude, azimuth}}}}}]) => ({ name: name.slice(0, 1).toUpperCase() + name.slice(1), altitude, azimuth })) .filter( planets => planetList.includes(planets.name)); planetSVG = planetSVG.data(planets) .join( enter => enter.append("g") .call(g => g.append("circle") .attr("r", planetRadius) .attr("fill", planetColor)) .call(g => g.append("text") .attr("fill", planetColor) .attr("dx", "-1em") .attr("dy", "1em") .attr("font-size", 16) .attr("font-face", "Open Sans") .text(d => visible.includes("planetNames") ? (d.name == "Mars" ? `♂` : d.name) : ``)), update => update, exit => exit.remove() ) .attr("transform", d => `translate(${projection([d.azimuth, d.altitude])})`); } }); }30:T9a2,// Adapted from https://observablehq.com/@jashkenas/inputs#worldMapCoordinatesDemo function worldMapCoordinates(config = {}) { var n_point; var lon, lat; const { value = [], title, description, width = width_small_map } = Array.isArray(config) ? {value: config} : config; const height = Math.round((210 / 400) * width); [lon, lat] = value[0]; lon = lon != null ? lon : null; lat = lat != null ? lat : null; const formEl = html``; const context = DOM.context2d(width, height); const canvas = context.canvas; canvas.style.margin = "10px 0 3px"; const projection = d3geo .geoNaturalEarth1() .precision(0.1) .fitSize([width, height], { type: "Sphere" }); const path = d3geo.geoPath(projection, context).pointRadius(point_radius); formEl.append(canvas); function draw() { context.fillStyle = "#fff"; context.fillRect(0, 0, width, height); context.beginPath(); path(graticule_Earth); context.lineWidth = 0.35; context.strokeStyle = "#ddd"; context.stroke(); context.beginPath(); path(land); context.fillStyle = "#f4f4f4"; context.fill(); context.beginPath(); path(countries); context.strokeStyle = "#aaa"; context.stroke(); if (lon != null && lat != null) { const pointPath = { type: "MultiPoint", coordinates: [[lon, lat]] }; context.beginPath(); path.pointRadius(point_radius); path(pointPath); context.fillStyle = color; context.fill(); } } canvas.onclick = function(ev) { const { offsetX, offsetY } = ev; var coords = projection.invert([offsetX, offsetY]); lon = +coords[0].toFixed(2); lat = +coords[1].toFixed(2); draw(); canvas.dispatchEvent(new CustomEvent("input", { bubbles: true })); }; draw(); const form = input({ type: "worldMapCoordinates", title, description, display: v => html`

Longitude: ${lon != null ? lon.toFixed(2) : " "}° Latitude: ${lat != null ? lat.toFixed(2) : ""}°

`, getValue: () => [lon != null ? lon : null, lat != null ? lat : null], form: formEl }); return form; }31:T951,// From https://observablehq.com/@jashkenas/inputs#worldMapCoordinatesDemo function input(config) { let { form, type = "text", attributes = {}, action, getValue, title, description, format, display, submit, options } = config; const wrapper = html`

`; if (!form) form = html``; Object.keys(attributes).forEach(key => { const val = attributes[key]; if (val != null) form.input.setAttribute(key, val); }); if (submit) form.append( html`` ); form.append( html`` ); if (title) form.prepend( html`

${title}

` ); if (description) form.append( html`

${description}

` ); if (format) format = typeof format === "function" ? format : d3format.format(format); if (action) { action(form); } else { const verb = submit ? "onsubmit" : type == "button" ? "onclick" : type == "checkbox" || type == "radio" ? "onchange" : "oninput"; form[verb] = e => { e && e.preventDefault(); const value = getValue ? getValue(form.input) : form.input.value; if (form.output) { const out = display ? display(value) : format ? format(value) : value; if (out instanceof window.Element) { while (form.output.hasChildNodes()) { form.output.removeChild(form.output.lastChild); } form.output.append(out); } else { form.output.value = out; } } form.value = value; if (verb !== "oninput") form.dispatchEvent(new CustomEvent("input", { bubbles: true })); }; if (verb !== "oninput") wrapper.oninput = e => e && e.stopPropagation() && e.preventDefault(); if (verb !== "onsubmit") form.onsubmit = e => e && e.preventDefault(); form[verb](); } while (form.childNodes.length) { wrapper.appendChild(form.childNodes[0]); } form.append(wrapper); return form; }32:[{"id":"b72a112dc112a45fd0512dc049a9fc9576e35356e0fa6bc6cca995c1036c4317cfa3cb9db9679eadcca9b1a85b46bdbf8c70eb8907d5208ac30f33f25da5ebd3","href":"https://static.observableusercontent.com/files/b72a112dc112a45fd0512dc049a9fc9576e35356e0fa6bc6cca995c1036c4317cfa3cb9db9679eadcca9b1a85b46bdbf8c70eb8907d5208ac30f33f25da5ebd3","name":"stars_(from_star-map_Mike_Bostock).csv","type":"text/csv","lastModified":1714058109889.734,"size":60896},{"id":"a1053ffe25ff79a39968a52028df663d5ff9e0d9dd420e9b79ccf10da4899bcf97b79c3e54d8d3f36b993e437d6a66f1541f59fb3b0f7e7ff254a5d1573310fe","href":"https://static.observableusercontent.com/files/a1053ffe25ff79a39968a52028df663d5ff9e0d9dd420e9b79ccf10da4899bcf97b79c3e54d8d3f36b993e437d6a66f1541f59fb3b0f7e7ff254a5d1573310fe","name":"ephemeris-2.0.0.js","type":"application/javascript","lastModified":1659088543961.087,"size":230067},{"id":"70b8357f6d7630f60808aee7d0f0d52832e42ee8c29f0ff10354fb800223db3b98c8ecee79b68b33e609806ae9da56cc97a6b7cd1d5f62736756f8f4dd9ac8ab","href":"https://static.observableusercontent.com/files/70b8357f6d7630f60808aee7d0f0d52832e42ee8c29f0ff10354fb800223db3b98c8ecee79b68b33e609806ae9da56cc97a6b7cd1d5f62736756f8f4dd9ac8ab","name":"stars.csv","type":"text/csv","lastModified":1659088543961.087,"size":60896},{"id":"5667cf6ea53cdbed31600d60556314bcefb28a3bbd66abb351464ab8cf0665cc3a4d508f73841f6ffa78ec215f8ee8acf29e09b8429409b30a3c7e4a18cc2f7f","href":"https://static.observableusercontent.com/files/5667cf6ea53cdbed31600d60556314bcefb28a3bbd66abb351464ab8cf0665cc3a4d508f73841f6ffa78ec215f8ee8acf29e09b8429409b30a3c7e4a18cc2f7f","name":"world-110m_withlakes.topo.json","type":"application/json","lastModified":1659115992615.723,"size":92469}] 2d:{"id":"fbea01f55becbc82","slug":"star-map-mars-ephemeris-year-2022-and-following","title":"Star map — Mars ephemeris (2022 and following years)","thumbnail":"2514a005cfa034a1f070158ec004956976882972cebe10b7d7feee79dc81c0be","access_level":"public","create_time":"$D2022-07-29T09:55:43.961Z","update_time":"$D2024-06-08T13:01:27.247Z","view_time":null,"first_public_time":"$D2022-07-29T19:16:38.119Z","has_unpublished_edits":null,"fork":{"id":"f8305470e0d78ed1","slug":"star-map-visualizing-the-retrograde-motion-of-mars","title":"Star map — Visualizing the apparent retrograde motion of Mars (1582-1600)","owner":{"id":"dd67891d326bcfb1","login":"christophe-yamahata","name":"Christophe Yamahata"}},"stars":2,"starred":false,"owner":{"type":"team","id":"dd67891d326bcfb1","login":"christophe-yamahata","name":"Christophe Yamahata","avatar_url":"https://avatars-next.observableusercontent.com/8256ac716aa8395babba412b2835913d186874fa4190df57a4a28f2e60129876","tier":"starter_2024"},"version":5945,"publish_version":null,"role":null,"authored":false,"authors":[{"type":"individual","id":"06f083eba60f5a76","login":"christophe-yamahata","name":"Christophe Yamahata","avatar_url":"https://avatars-next.observableusercontent.com/8256ac716aa8395babba412b2835913d186874fa4190df57a4a28f2e60129876","tier":null}],"members":[{"type":"individual","id":"06f083eba60f5a76","login":"christophe-yamahata","name":"Christophe Yamahata","avatar_url":"https://avatars-next.observableusercontent.com/8256ac716aa8395babba412b2835913d186874fa4190df57a4a28f2e60129876","tier":null,"role":"editor"}],"comments":[],"custom_thumbnail":true,"trashed":false,"lapsed":null,"subscribed":null,"forks":2,"collection":{"id":"b9eb9f21a877b3c2","slug":"tycho-brahe-and-mars","title":"Tycho Brahe and Mars (♂)","owner":{"id":"dd67891d326bcfb1","login":"christophe-yamahata","name":"Christophe Yamahata"}},"type":"notebook","body":{"title":"Star map — Mars ephemeris (2022 and following years)","cells":[{"id":2327,"value":"# Star map — Mars ephemeris (2022 and following years)","pinned":false,"hidden":false,"mode":"md","author":"$undefined","summary":"$undefined","output":"","database":"$undefined"},{"id":0,"value":"

\n This is a fork of my notebook on the observations of Mars completed by Tycho Brahe during the period 1582-1600. \n

\n","pinned":false,"hidden":false,"mode":"html","author":"$undefined","summary":"$undefined","output":"","database":"$undefined"},{"id":5585,"value":"

Star map

","pinned":false,"hidden":false,"mode":"html","author":"$undefined","summary":"$undefined","output":"","database":"$undefined"},{"id":2489,"value":"

\n The star map shows the night sky as you could observe it in our time (year ${new Date().getFullYear()}, period 2020 – ${new Date().getFullYear()+10}) from the location selected on the map.\n

\n Location: [ Lat. ${φo > 0 ? '+'+φo.toFixed(2)+'° (North)' : (φo < 0 ? φo.toFixed(2)+'° (South)' : φo.toFixed(2)+'°')}, Lon. ${λo > 0 ? '+'+λo.toFixed(2)+'° (East)' : (λo < 0 ? λo.toFixed(2)+'° (West)' : λo.toFixed(2)+'°')} ]\n
\n Selected period: 01/${observation_period[0]} … 12/${observation_period[1]} \n

\n All calulations are based on the ephemeris JavaScript library (v. 2.0.0). Note that this library suffers from few minor inaccuracies.\n

","pinned":false,"hidden":false,"mode":"html","author":"$undefined","summary":"$undefined","output":"","database":"$undefined"},{"id":5860,"value":"
\n

Select a location on Earth

","pinned":false,"hidden":false,"mode":"html","author":"$undefined","summary":"$undefined","output":"","database":"$undefined"},{"id":5778,"value":"viewof location = worldMapCoordinates([[λo_initial, φo_initial]])","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":5547,"value":"
\n

Set the observation period

","pinned":false,"hidden":false,"mode":"html","author":"$undefined","summary":"$undefined","output":"","database":"$undefined"},{"id":2529,"value":"viewof observation_period = interval([2020, new Date().getFullYear()+10], {\n step: 1,\n value: [new Date().getFullYear(), new Date().getFullYear()+3],\n format: ([start, end]) => `January ${start} … December ${end}`,\n label: 'Observation period'\n})","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":5598,"value":"
","pinned":false,"hidden":false,"mode":"html","author":"$undefined","summary":"$undefined","output":"","database":"$undefined"},{"id":1630,"value":" viewof date = Scrubber(d3.utcDays(Date.parse(dateStart), Date.parse(dateEnd)), {\n autoplay: true, loopDelay: 2000, delay: 0, loop: true,\n format: d3.utcFormat(\"%b %d, %Y\")})","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":2334,"value":"viewof visible = checkbox({\n title: \"Set visibility\",\n options: [\n { value: \"planetNames\", label: \"♂ symbol\" },\n { value: \"planetPath\", label: \"Planet's path\" },\n { value: \"ecliptic\", label: \"Ecliptic plane\" },\n { value: \"equator\", label: \"Equatorial plane\" },\n { value: \"graticule\", label: \"Graticule (azimuthal grid)\" },\n { value: \"celestial_poles\", label: \"Big dipper asterism, Crux & Celestial poles\" }\n ],\n value: [\"planetPath\", \"ecliptic\", \"equator\", \"graticule\", \"celestial_poles\"]\n})","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":17,"value":"$2f","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":2553,"value":"viewof hour_angle = slider({\n title: \"Observation angle (hour angle)\",\n description: \"Slide to change the observation angle (i.e., hour of observation)\",\n min: -180,\n max: 180,\n step: 30,\n value: 0,\n format: v => html`${v > 0? '+'+v : v}° (${v > 0? '+'+v/15 : v/15}^h)`,\n})","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":4078,"value":"Inputs.table(Mars_altaz, {\n columns: [\n \"date\",\n \"altitude\",\n \"azimuth\",\n \"Dec\",\n \"RA\"\n ],\n\n header: {\n date: \"Date of observation of ♂\",\n altitude: \"Altitude (°)\",\n azimuth: \"Azimuth (°)\",\n Dec: \"Declination (°)\",\n RA: \"Right Ascension (°)\"\n },\n \n align: {\n date: \"left\",\n altitude: \"center\",\n azimuth: \"center\",\n Dec: \"center\",\n RA: \"center\"\n },\n \n width: {\n date: 120,\n altitude: 80,\n azimuth: 80,\n Dec: 110,\n RA: 110\n },\n\n maxWidth: 800,\n maxHeight: 50,\n height: 50\n})","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":5881,"value":"
","pinned":false,"hidden":false,"mode":"html","author":"$undefined","summary":"$undefined","output":"","database":"$undefined"},{"id":5866,"value":"### Mars retrograde periods (2020 – 2031)\n\n| Year (start) | Period | \n|--------------|----------------------------------|\n| 2020 | Sept. 9 – Nov. 13 | \n| 2022 | Oct. 30, 2022 – Jan. 12, 2023 |\n| 2024 | Dec. 6, 2024 – Feb. 23, 2025 |\n| 2027 | Jan. 10 – April 1 |\n| 2029 | Feb. 14 – March 5 |\n| 2031 | March 28 – June 13 |","pinned":false,"hidden":false,"mode":"md","author":"$undefined","summary":"$undefined","output":"","database":"$undefined"},{"id":2495,"value":"

\n
\n

Appendices

","pinned":false,"hidden":false,"mode":"html","author":"$undefined","summary":"$undefined","output":"","database":"$undefined"},{"id":2500,"value":"### Parameters / Constants","pinned":false,"hidden":false,"mode":"md","author":"$undefined","summary":"$undefined","output":"","database":"$undefined"},{"id":5811,"value":"geolocation = new Promise((resolve, reject) => {\n let myPositionCallbackFunction = (position) => resolve(position.coords);\n let myPositionErrorCallbackFunction = (error) => reject(error.message);\n \n navigator.geolocation.getCurrentPosition(\n myPositionCallbackFunction,\n myPositionErrorCallbackFunction,\n { enableHighAccuracy: true, timeout: 5000 }\n );\n}).catch(error => error);","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":5814,"value":"browser_lat_lon = [geolocation.latitude, geolocation.longitude]","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":2523,"value":"φo_initial = browser_lat_lon[0]? browser_lat_lon[0] : 56.0881 // observer’s latitude (degrees)","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":2527,"value":"λo_initial = browser_lat_lon[1]? browser_lat_lon[1] : 12.6966 // Observer's longitude (degrees)","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":5520,"value":"φo = location[1]","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":5511,"value":"λo = location[0]","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":2046,"value":"J2000 = Date.UTC(2000, 0, 1, 12)","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":2918,"value":"julianCentury = date => {\n var Year = d3.utcFormat(\"%Y\");\n var Month = d3.utcFormat(\"%m\");\n var Day = d3.utcFormat(\"%d\");\n var Hour = hour_angle/15;\n return (Date.UTC(Year(date), Month(date)-1, Day(date), Hour) - Date.UTC(2000, 0, 1, 12) ) / 315576e7 ;\n}","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":5180,"value":"observationStart = observation_period[0]","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":5183,"value":"observationEnd = observation_period[1]","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":5163,"value":"dateStart = observationStart+'-01-01'","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":5167,"value":"dateEnd = observation_period[1]+'-12-31'","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":3108,"value":"dateHour = new Date(Date.parse(date)+0.5*86400000*hour_angle/180)","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":5753,"value":"---\n### Earth","pinned":false,"hidden":false,"mode":"md","author":"$undefined","summary":"$undefined","output":"","database":"$undefined"},{"id":5766,"value":"color = \"#228\"","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":5742,"value":"width_small_map = Math.min(550,Math.max(document.documentElement.clientWidth || 0, window.innerWidth || 0)-20)","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":5748,"value":"point_radius = 3","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":5796,"value":"graticule_Earth = d3.geoGraticule10()","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":5756,"value":"world = FileAttachment(\"world-110m_withlakes.topo.json\").json();","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":5751,"value":"land = topojson.feature(world, world.objects.land)","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":5759,"value":"countries = topojson.feature(world, world.objects.countries)","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":2114,"value":"---\n### Stars","pinned":false,"hidden":false,"mode":"md","author":"$undefined","summary":"$undefined","output":"","database":"$undefined"},{"id":2200,"value":"nStars = 500","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":2118,"value":"starRadius = d3.scaleLinear([6, -1], [0, 2])","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":2760,"value":"starColor = \"#fafafa\"","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":2772,"value":"darkSky = \"#000028\"","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":2116,"value":"// Edit 25.04.2024 \n// > await FileAttachment(\"stars.csv\").txt()\n// replaced with > await FileAttachment(\"stars_(from_star-map_Mike_Bostock).csv\").text()\n// CSV file on that notebook: https://observablehq.com/@d3/star-map\nstars = (d3.csvParse(await FileAttachment(\"stars_(from_star-map_Mike_Bostock).csv\").text(), d => {\n d3.autoType(d);\n return {\n magnitude: d.magnitude,\n radius: starRadius(d.magnitude),\n ra: hms(d.RA_hour, d.RA_min, d.RA_sec),\n dec: dms(d.dec_deg, d.dec_min, d.dec_sec),\n };\n})).sort((a, b) => d3.ascending(a.magnitude, b.magnitude)).slice(0, nStars)","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":4437,"value":"// δ UMa / RA 12h 15m 25.56063s / Dec +57° 01′ 57.4156″\n\n// α UMa / RA 11h 03m 43.67152s / Dec\t+61° 45′ 03.7249″\n// β UMa / RA 11h 01m 50.47654s / Dec\t+56° 22′ 56.7339″\n// γ UMa / RA 11h 53m 49.84732s / Dec\t+53° 41′ 41.1350″\n\n// ε UMa / RA 12h 54m 01.74959s / Dec\t+55° 57′ 35.3627″\n// ζ UMa / RA 13h 23m 55.54048s / Dec\t+54° 55′ 31.2671″\n// η UMa / RA \t13h 47m 32.43776s / Dec\t+49° 18′ 47.7602″\n\nbig_dipper = [[183.857,57.033],[165.932,61.751],[165.460,56.382],[178.458,53.695],[183.857,57.033],[193.507,55.960],[200.981,54.925],[207.089,49.313]] ","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":5689,"value":"// α Cru A / RA 12h 26m 35.94s /\tDec −63° 05′ 56.6″\n// γ Cru / RA 12h 31m 09.93s / Dec\t−57° 06′ 45.2″\ncrux1 = [[186.65,-63.1], [187.79,-57.1]];\n","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":5707,"value":"// δ Cru / RA 12h 15m 08.76s / Dec −58° 44′ 56.0″\t(-58.75°)\n// β Cru / RA 12h 47m 43.26877s/ Dec −59° 41′ 19.5792″ (-59.69°)\ncrux2 = [[183.79,-57.25], [191.93,-58.3]]; ","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":2222,"value":"### Planet Mars","pinned":false,"hidden":false,"mode":"md","author":"$undefined","summary":"$undefined","output":"","database":"$undefined"},{"id":2460,"value":"planetRadius = 3","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":2753,"value":"planetColor = \"#ffbb22\"","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":3234,"value":"eclipticColor = planetColor","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":2229,"value":"planetList = [\"Mars\"]","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":5254,"value":"function Mars_path(i) { return Object.entries(ephemeris.getAllPlanets(i, λo, φo, 0).observed)\n .map(([name, {raw: {position: {altaz: {topocentric: {dRA, dec}}}}}]) => ({\n name: name.slice(0, 1).toUpperCase() + name.slice(1),\n date: i,\n RA: 15*(dRA.hours+dRA.minutes/60+(dRA.seconds+dRA.milliseconds/1000)/3600),\n Dec: dec*180/(Math.PI),\n }))\n .filter( planet => planet.name == \"Mars\");\n}","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":4074,"value":"Mars_altaz = Object.entries(ephemeris.getAllPlanets(dateHour, λo, φo, 0).observed)\n .map(([name, {raw: {position: {altaz: {topocentric: {altitude, azimuth, dRA, dec}}}}}]) => ({\n name: name.slice(0, 1).toUpperCase() + name.slice(1),\n date: dateHour,\n altitude, \n azimuth,\n RA: 15*(dRA.hours+dRA.minutes/60+(dRA.seconds+dRA.milliseconds/1000)/3600),\n Dec: dec*180/(Math.PI),\n }))\n .filter( planet => planet.name == \"Mars\");","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":5428,"value":"Mars_path_RA_Dec = {\n var array = [];\n for(var i = 0; i < 10; i++) {\n var row = [[Mars_path(previousDate(i*20))[0].RA, Mars_path(previousDate(i*20))[0].Dec]];\n array = array.concat(row);\n }\n return array;\n}","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":695,"value":"---\n### Plotting","pinned":false,"hidden":false,"mode":"md","author":"$undefined","summary":"$undefined","output":"","database":"$undefined"},{"id":13,"value":"width = 600","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":11,"value":"height = width","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":1639,"value":"chart.update(date);","pinned":true,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":5282,"value":"function previousDate(i) {\n var Year = d3.utcFormat(\"%Y\");\n var Month = d3.utcFormat(\"%m\");\n var Day = d3.utcFormat(\"%d\");\n return new Date(Year(date),Month(date)-1,Day(date)-i,0,0,0);\n}","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":43,"value":"graticule = d3.geoGraticule()\n .stepMinor([10, 15])\n .extentMajor([[-180, 0], [180, 89]])\n .extentMinor([[-180, 0], [180, 89]])()","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":3199,"value":"textColor = \"#B0A0A0\"","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":3397,"value":"lightGrey = \"#B0B0B0\"","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":3808,"value":"darkGrey = \"F0F0F0\"","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":3615,"value":"equatorColor = \"#FF0044\"","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":4462,"value":"asterismColor = \"orange\"","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":33,"value":"path = d3.geoPath(projection)","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":8,"value":" projection = d3.geoStereographic()\n .scale((width-115) / 2)\n .clipExtent([[0, 0], [width, height]]) \n .rotate([180, -90]) // use North-oriented azimuth\n .translate([width / 2, height / 2])\n .precision(0.1) ","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":98,"value":"xAxis = g => g\n .call(g => g.append(\"g\")\n .attr(\"stroke\", \"currentColor\")\n .selectAll(\"line\")\n .data(d3.range(360))\n .join(\"line\")\n .datum(d => [\n projection([d, 0]),\n projection([d, d % 10 ? -1 : -2])\n ])\n .attr(\"x1\", ([[x1]]) => x1)\n .attr(\"x2\", ([, [x2]]) => x2)\n .attr(\"y1\", ([[, y1]]) => y1)\n .attr(\"y2\", ([, [, y2]]) => y2))\n .call(g => g.append(\"g\")\n .selectAll(\"text\")\n .data(d3.range(0, 360, 10))\n .join(\"text\")\n .attr(\"dx\", d => d === 0 ? 0 : (d === 90 ? -12 : (d === 180 ? 0 : (d === 270 ? 12 : (d > 180 ? \"0.4em\" : (d < 90 ? \"-0.3em\" :\"-0.6em\"))))))\n .attr(\"dy\", d => d === 0 ? \"-0.1em\" : (d === 180 ? \"0.9em\" : \"0.4em\"))\n .text(d => d === 0 ? \"N\" : d === 90 ? \"E\" : d === 180 ? \"S\" : d === 270 ? \"W\" : `${d}°`)\n .attr(\"font-size\", d => d % 90 ? 12 : 26)\n .attr(\"font-weight\", d => d % 90 ? null : \"bold\")\n .datum(d => projection([d, -4]))\n .attr(\"x\", ([x]) => x)\n .attr(\"y\", ([, y]) => y))","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":1954,"value":"yAxis = g => g\n .call(g => g.append(\"g\")\n .selectAll(\"text\")\n .data(d3.range(15, 90, 15))\n .join(\"text\")\n .attr(\"dy\", \"0.3em\")\n .attr(\"font-size\", 12)\n .text(d => `${d}°`)\n .datum(d => projection([-45, d]))\n .attr(\"x\", ([x]) => x)\n .attr(\"y\", ([, y]) => y))","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":1729,"value":"circle_ = d3.range(10).map(i => [i / 9 * 360, 0]) // will be resampled by D3","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":41,"value":"horizon = d3.geoCircle().radius(90).center([0, 90])()","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":2447,"value":"---\n## Imports","pinned":false,"hidden":false,"mode":"md","author":"$undefined","summary":"$undefined","output":"","database":"$undefined"},{"id":1580,"value":"ephemeris = require(await FileAttachment(\"ephemeris-2.0.0.js\").url())","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":1989,"value":"import { ecliptic2equatorial, equatorial2horizontal, invertAzimuth, hms, dms } from \"@mbostock/star-map/2\"","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":1915,"value":"import {slider, checkbox, select, date as dateSelector } from \"@jashkenas/inputs\"","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":5745,"value":"d3geo = require(\"d3-geo@1\")","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":5775,"value":"d3format = require(\"d3-format@1\")","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":4,"value":"d3 = require(\"d3@6\")","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":1627,"value":"import {Scrubber} from \"@mbostock/scrubber\"","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":2531,"value":"import {interval} from \"@mootari/range-slider\"","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":5736,"value":"$30","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":5772,"value":"$31","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"}],"files":"$W32","stdlib":"1","titling":"auto"}} 2e:"$2d:body"