What is the best sky projection to use for my purposes?

In summary, the conversation discusses the need for a projection in Python to accurately show the movement of the moon and sun across the night sky without distorting their shapes. The postdoc suggests using a Lambert conformal projection, but the speaker also considers trying out other projections on planetarium software. They also mention that most planetarium software only project the positions of astronomical objects, not their actual shapes. The speaker believes that for their purpose of creating constellation maps, having distorted stars is not a major concern and would prefer a stereographic projection for preserving shapes near a point of interest.
  • #1
Simfish
Gold Member
823
2
So basically I want to write some code in Python to project the movement of the moon and sun across the night sky. Basically, I need a projection such that the shape of the moon won't change as it moves in the sky (especially when it's near the horizon) - the objects have to look fairly good rather than ugly and distorted. My postdoc hypothesizes that a Lambert conformal projection (which preserves angles) would be the best projection to use. What are your thoughts?

She also suggested that I try out a variety of projections on planetarium software, although the planetarium software I've downloaded don't have a lot of projections to compare with (in particular, none of them have both a Lambert conformal and a stereographic projection). Is there planetarium software that allows you to experiment with a wide variety of projections? Would a stereographic projection work well (compared to a Lambert conformal projection?)

I think another key thing is this: what we're trying to plot should look more like a constellation map than like a view of the sky from a particular person's perspective.
 
Last edited:
Astronomy news on Phys.org
  • #2
Most planetarium software that I know of only project the position of astronomical objects. The objects themselves are basically static images that are increased or decreased in size according to the zoom level.

Also, since you mention that the primary purpose of your script is to generate constellation maps, I don't believe that having or not having distorted stars would matter much.

Personally, I would go with stereographic projection, to conserve shapes near a point of interest.
 

FAQ: What is the best sky projection to use for my purposes?

What is the best sky projection to use for my purposes?

The best sky projection to use depends on your specific purposes and needs. Here are the top 5 most frequently asked questions about choosing a sky projection:

1. What is the difference between a cylindrical and spherical sky projection?

A cylindrical sky projection shows the sky as a flat, rectangular map, while a spherical sky projection shows the sky as a curved, round map. Cylindrical projections are better for studying the patterns of stars and constellations, while spherical projections are better for studying the movement of celestial objects and understanding their positions in relation to each other.

2. Which sky projection is best for navigation?

The Mercator projection is often used for navigation purposes as it preserves angles and shapes, making it easy to plot a course or determine the direction of a celestial object. However, it does distort the size of objects and distances, so it may not be the best choice for all purposes.

3. Can I use a flat sky projection for accurate measurements?

No, flat sky projections, such as the azimuthal equidistant projection, can only accurately show the positions of celestial objects at a specific point on the projection. They are not suitable for making accurate measurements or calculations.

4. Is there a sky projection that is best for all purposes?

No, there is no one-size-fits-all sky projection that is best for all purposes. Each projection has its own strengths and weaknesses, and the best one to use will depend on your specific needs and goals.

5. Can I create my own custom sky projection?

Yes, it is possible to create a custom sky projection using specialized software. However, it requires knowledge and understanding of cartography and astronomy, and may not be necessary for most purposes.

Back
Top