Star maps using Blender

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Blender just recently dropped a new version, 4.5(with 5.0 on the horizon), and within it was a new feature for which I immediately thought of a use for. The new feature was a .csv importer for Geometry nodes. Geometry nodes are a method of modelling that uses a node tree to create 3D models which offers more flexibility than straight modeling does. The .csv importer node allows you to bring in a .csv file and use the data in it to control aspects of your model. So for example, if you had a list of Right Ascensions, Declinations, and distances of celestial objects, you can use this to create a 3D map of them. Each value can be pulled out as an attribute node and used to define your model.
As luck would have it, there is a site called VisizeR that has a ton of catalogues of such objects, which can be searched and shown in table form. These tables can then be copy and pasted into a spreadsheet program and saved as a .csv file.
These VizieR tables can also be modified to show only the data you are interested in, and constrained by limits. For example, you could have a table list only G class stars out to 100 lys.
Such a map for all stars out to 100 ly is shown here:
stars_100ly.webp

This is an overlay of separate models. One for each spectral class of star, with each class given its correct Black body temperature color. This is useful if, for instance, you wanted to only show a particular class of star, which can be done by simple hiding the models for the other classes. If this particular file also had the visual magnitudes, you can create an attribute node for this, and then use it to control whether a star appears in the model, or possibly the visual appearance of the star( like the size representing visual magnitude).
The above image, being a still one, doesn't quite do the model justice, as the three dimensionality of it isn't apparent. For that, an animation is more appropriate.
This YouTube video of three different models gives a better showing. The 1st model is of all stars out to 175 parsecs (About the distance to Polaris), the 2nd is of DCEP Cepheid stars using the z red-shift for distances, and the 3rd is galaxy clusters detected by X-rays.


So far, I've only scraped the surface of what can be done with this new tool, and it's going to be fun to figure out other uses for it.
 
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Janus said:
Blender just recently dropped a new version, 4.5(with 5.0 on the horizon), and within it was a new feature for which I immediately thought of a use for. The new feature was a .csv importer for Geometry nodes. Geometry nodes are a method of modelling that uses a node tree to create 3D models which offers more flexibility than straight modeling does. The .csv importer node allows you to bring in a .csv file and use the data in it to control aspects of your model. So for example, if you had a list of Right Ascensions, Declinations, and distances of celestial objects, you can use this to create a 3D map of them. Each value can be pulled out as an attribute node and used to define your model.
As luck would have it, there is a site called VisizeR that has a ton of catalogues of such objects, which can be searched and shown in table form. These tables can then be copy and pasted into a spreadsheet program and saved as a .csv file.
These VizieR tables can also be modified to show only the data you are interested in, and constrained by limits. For example, you could have a table list only G class stars out to 100 lys.
Such a map for all stars out to 100 ly is shown here:
View attachment 366389
This is an overlay of separate models. One for each spectral class of star, with each class given its correct Black body temperature color. This is useful if, for instance, you wanted to only show a particular class of star, which can be done by simple hiding the models for the other classes. If this particular file also had the visual magnitudes, you can create an attribute node for this, and then use it to control whether a star appears in the model, or possibly the visual appearance of the star( like the size representing visual magnitude).
The above image, being a still one, doesn't quite do the model justice, as the three dimensionality of it isn't apparent. For that, an animation is more appropriate.
This YouTube video of three different models gives a better showing. The 1st model is of all stars out to 175 parsecs (About the distance to Polaris), the 2nd is of DCEP Cepheid stars using the z red-shift for distances, and the 3rd is galaxy clusters detected by X-rays.


So far, I've only scraped the surface of what can be done with this new tool, and it's going to be fun to figure out other uses for it.

Nice. So given a 3D star map, could one find out what the constellations look like from different stars? Like, which constellation would the sun be in as seen from Alpha Centauri?
 
AlexB23 said:
Nice. So given a 3D star map, could one find out what the constellations look like from different stars? Like, which constellation would the sun be in as seen from Alpha Centauri?
Technically I could be done, though some adjustments would likely be needed to be made. For Alpha C, you should just be able to move the camera to its position and point it at our Sun in the model. For stars significantly further, it would take some additional work. Let's put it this way: Our own Sun would only be visible to the unaided eye at a maximum of ~50 ly. So from further than that you wouldn't even see the Sun without a telescope. Or take Eta Cassiopeiae, which from Earth is visible as a star with a magnitude of 3.48. If we were viewing our Sun from a direction so that Cassiopeiae was in the background, At a certain distance, this star would drop below visibility and no longer be part of the visible constellation. If you want a really accurate of what things would look like from a given point in space, you'd have to work out what stars you could see and which you couldn't. In addition, there are a ton of smaller red dwarf stars, that we don't see, but might be visible from another star system and between us and that star. in this case they would see an additional star besides our Sun in the background constellation.
 
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Janus said:
Technically I could be done, though some adjustments would likely be needed to be made. For Alpha C, you should just be able to move the camera to its position and point it at our Sun in the model. For stars significantly further, it would take some additional work. Let's put it this way: Our own Sun would only be visible to the unaided eye at a maximum of ~50 ly. So from further than that you wouldn't even see the Sun without a telescope. Or take Eta Cassiopeiae, which from Earth is visible as a star with a magnitude of 3.48. If we were viewing our Sun from a direction so that Cassiopeiae was in the background, At a certain distance, this star would drop below visibility and no longer be part of the visible constellation. If you want a really accurate of what things would look like from a given point in space, you'd have to work out what stars you could see and which you couldn't. In addition, there are a ton of smaller red dwarf stars, that we don't see, but might be visible from another star system and between us and that star. in this case they would see an additional star besides our Sun in the background constellation.
Fascinating stuff. Once everything is set up, make some views from different stars within say 20 light years of the sun.
 
Janus said:
Technically I could be done, though some adjustments would likely be needed to be made.
Also, our angular coordinate information is very precise, but IIRC our distance estimates have some pretty large error bars (Betelgeuse, for example, is between 408 and 548 ly away). So our estimates of the positions of stars on somebody else's night sky elsewhere would quickly become very unreliable as you move away from Earth.
 
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This is pretty cool. I was always fascinated by those galactic and superckuster maps in modern astronomy books and would at them in wonderment.
 
A couple more examples. The first incorporates proper motion data to show how Ursa Major would change over time. I included other visible stars and their proper motions as well. The second touches on the change of view due to position and shows how the constellation would change as the viewing angle changes.
 

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