codebox/star-charts

Generate SVG star charts using Python

Star Charts

This Python script will generate SVG star charts, like the ones shown below:

^{The constellation Orion, showing stars down to magnitude 8 original SVG}

The script reads data about the position and brightness of stars from a CSV file like this one. Each row in the CSV file contains information about a single star in 4 columns as follows:

• Right-Ascension: the star's angular distance eastward from the vernal equinox (0 to 24)
• Declination: the star's angular distance northward from the celestial equator (-90 to +90)
• Magnitude: the star's brightness
• Label: an optional field used to add labels to stars (see the Greek letters in the example chart above)

For example

5.91937636,+76.86957095, 8.07
5.91952477,+07.40703634, 0.45,α
5.92011402,+61.86673905, 8.60
5.92045102,-73.15075170, 7.72

The area to be covered by the chart is specified using a SkyArea object, which must be referenced the main.py file. A few pre-defined areas are included, such as complete northern and southern sky maps:

^{Maps of the Northern and Southern skies, showing stars down to magnitude 7 (original SVGs: North and South}

The script is run by simply executing the main.py file, as follows:

python main.py

The SVG file will be created in the current directory, and will be named star-chart.svg

Please note that the script is designed to be run using Python 3, it will not run correctly with Python 2.

star-charts's Issues

Is there a plan to package this for pypi?

It would be cool if it was packaged so it could be installed with pip. # #

Overlapping RA

Hi,
I find there's no way to construct a SkyArea with RA coordinates overlapping the 0h mark.
For instance, if I wanted to build a sky area like this:

area = sky_area.SkyArea(23, 1, 10, 30, 8)

It would print the external segment of the celestial sphere (going from 01h to 23h) instead of the internal (from 23h to 01h).
You can see an attached screenshot.

Am I missing something? Is there a better way to create a SkyArea with these coordinates?
I'm looking for a solution myself and see if I can create a PR, but I think it's a bit beyond my understandings.

Cheers,
Marco

Stardata orgin

I like this project very much.
Could you please share the origin of the stardata.

Better coordinates support

Hi,
I didn't find a way to express RA ranges overlapping 0, like [-350, 10].

From a user perspective I think this problem would be more easily solved by using a single coordinate (center of field) and a radius, instead of providing start/end ra/dec.
Is there any chance of seeing this implemented?

Python version?

Hi, I'm not very knowledgeable about Python and I wanted to use this utility to generate a chart and after some testing, I figured I needed to use Python 2.7, and trying to using Python 3.6 wouldn't generate the chart correctly.

Would it be possible to add a mention about some prerequisite in the readme to save some time for other newcomers like me? Thanks for your work on this!

Draws both hemispheres

I'm finding that both opposites of the celestial hemispheres are drawn.
Observing this while porting to JS and animating.
render_svg() does no skip any stars.

Or am I missing something?

Fixed offset and scale map on Python3

Hey all, this looks great! I downloaded it earlier today and found that on Python3 the generated SVG didn't scale the stars' positions correctly. I found that the issue was on the map call around line 70 of the coord_calc.py file and fixed it by replacing it with a for loop with the contents of offset_and_scale instead. I'm not very sure how to suggest a commit so I just bring this up here. Best of luck! Awesome job it's great!