60 lines
2.8 KiB
HTML
60 lines
2.8 KiB
HTML
<p>
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There are a couple of online services that offer the creation of a poster that contains the night's sky at a certain
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point in time and space, but they all want to be paid handsomely. So, do it ourselves then! A quick search for input
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data resulted in the following database:
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</p>
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<p>
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<a target="_blank" href="https://github.com/astronexus/HYG-Database">https://github.com/astronexus/HYG-Database</a>
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</p>
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<p>
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After a failed attempt at trying to understand the basics of astronomy I found a
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<a target="_blank" href="http://jknight8.tripod.com/CelestialToAzEl.html#the%20source%20code">concise explanation</a>
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of how you can calculate the visible night sky for a specific observer.
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I implemented this algorithm, quick and dirty, in a Kotlin project (check out
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<a target="_blank" href="https://github.com/CountZukula/hygsvg">my github repository</a> if you want to try it out).
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The code outputs a vector image and I'm pretty pleased with the
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result. As it's in vector format, it can be easily modified without loss of quality, meaning you can produce posters
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of whichever size you desire.
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</p>
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<p>Below are some sample screenshots. I'm not rendering the full image here, to avoid a slow load of this page, but you
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can download an example <a href="https://github.com/CountZukula/hygsvg/blob/master/example/stars.svg">here</a> to open
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with your favorite image viewer.</p>
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<div class="row">
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<div class="col-md-12">
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<figure class="figure">
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<img src="/assets/post/hygsvg/img/stars1.png" class="figure-img img-fluid rounded"
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alt="The whole hemisphere, projected on a circle.">
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<figcaption class="figure-caption">The whole hemisphere, projected on a circle.</figcaption>
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</figure>
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</div>
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<div class="col-md-12">
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<figure class="figure">
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<img src="/assets/post/hygsvg/img/stars3.png" class="figure-img img-fluid rounded"
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alt="Slightly zoomed in ...">
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<figcaption class="figure-caption">Slightly zoomed in ...</figcaption>
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</figure>
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</div>
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<div class="col-md-12">
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<figure class="figure">
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<img src="/assets/post/hygsvg/img/stars2.png" class="figure-img img-fluid rounded"
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alt="Zoomed in all the way!">
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<figcaption class="figure-caption">Zoomed in all the way!</figcaption>
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</figure>
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</div>
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</div>
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<p>
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Most parameters can be easily modified (size of the stars, colors, ...), either by changing some variables or
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modifying the code (which should be relatively easy. It's currently possible to have the stars' colors correspond to
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their actual class (if it's known in the database), meaning that the star is blue when hot, and reddish when cool.
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Stars are also portrayed bigger when they are more bright in the sky, which made sense to me, as a non-astronomer.
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</p>
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<p>
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Off to the printer!
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</p>
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