Public
Edited
Dec 3, 2022
Importers
2 stars
stars = Array.from(parse())
stars
Type Table, then Shift-Enter. Ctrl-space for more options.
buffer = FileAttachment("BSC5").arrayBuffer()
littleEndian = true
function* header() {
const view = new DataView(buffer)
for (let i = 0; i < 28; i += 4)
yield view.getInt32(i, littleEndian)
}
function* parse() {
const utf8decoder = new TextDecoder()
const [ star0, star1, starn, stnum, mprop, nmag, nbent ] = header()
const view = new DataView(buffer.slice(28))
let offset = 0
while (offset < -starn * nbent) {
const xno = view.getFloat32(offset, littleEndian); offset += 4
const sra0 = view.getFloat64(offset, littleEndian); offset += 8
const sdec0 = view.getFloat64(offset, littleEndian); offset += 8
const is = utf8decoder.decode(new Uint8Array([view.getUint8(offset, littleEndian), view.getUint8(offset+1, littleEndian)])); offset += 2
const mag = view.getInt16(offset, littleEndian) / 100; offset += 2
const xrpm = view.getFloat32(offset, littleEndian); offset += 4
const xdpm = view.getFloat32(offset, littleEndian); offset += 4
yield { xno, sra0, sdec0, is, mag, xrpm, xdpm }
}
}
catalog
Type Table, then Shift-Enter. Ctrl-space for more options.
catalog = (await FileAttachment('bsc5.dat.txt').text()).trim().split('\n').map(line => {
const name = line.substring(4, 14).trim()
const constellation = name && name.substring(name.length - 3)
return {
hr: +line.substring(0, 4).trim(),
name,
constellation,
bv: +line.substring(109, 114),
ub: +line.substring(115, 120),
// line
}
})
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