<p>I would guess: No. The tropic of Cancer and tropic of Capricorn make sense on the Earth's surface, because the Earth is &quot;rotating underneath&quot; (in an Earth-centered view), so the ecliptic &quot;gets smeared&quot; into a band between the tropics. However, the ecliptic is &quot;stuck to&quot; the celestial sphere and doesn't &quot;get smeared&quot; as it rotates in step with the sphere.</p>
<p>Sorry for putting things in quotes - hope you get the idea, but I can't find other words for the ideas, just as I don't think there is a word, or a compelling need for a word, for what you are describing.</p>

CC BY-SA 4.0
2024-06-24T22:58:27.673Z
>" the ecliptic "gets smeared" into a band between the tropics." ==[  Yes! That answer is wonderful and delightful! Ty!
Miss Understands
CC BY-SA 4.0
2024-06-24T22:05:06.900Z
2024-06-24T22:05:06.900Z
DavidWalley
<p>The projection of earth's equator is the celestial equator. The ecliptic oscillates above and below it in a year, and the furthest north it goes is the projection onto the celestial sphere of the tropic of cancer.</p>
<p>Is there a name for it? It parallels the celestial equator at 23.5 deg declination.</p>

CC BY-SA 4.0
2024-06-24T22:12:49.317Z
I'm having a hard time thinking of any reason such a marker would be of any interest in the sky. The equator is the zero plane, so the projected tropics would just be, well, the 23.5 degrees line.
Darth Pseudonym
CC BY-SA 4.0
2024-06-24T22:53:42.913Z
Yeah, well, I pay attention to stuff other people don't care about. When I was a kid, I turned stuff over to see what's underneath, and took stuff apart to see how it works.  It's a curse from God.
Miss Understands
CC BY-SA 4.0
2024-06-24T23:00:44.913Z
In sundial terminology, the same names are used for the declination circles as the corresponding latitude circles. https://sundials.org/index.php/teachers-corner/sundial-construction/200-armillary-sundial.html
PM 2Ring
CC BY-SA 4.0
2024-06-26T14:49:58.520Z
An Armilary Sphere (usually) has rings to denote the celestial equivalents of the these.  The Wikipedia entry has an image with many of the parts labeled.  It just calls them "Tropic of Cancer" and "Tropic of Capricorn".  You might try digging deeper.  https://en.wikipedia.org/wiki/Armillary_sphere
Greg Miller
<declination><ecliptic>
What's the name of the projection onto the celestial sphere of the tropic of cancer?
Miss Understands
# What's the name of the projection onto the celestial sphere of the tropic of cancer?

(Asked by: username_0 on 2024-06-24)

The projection of earth's equator is the celestial equator. The ecliptic oscillates above and below it in a year, and the furthest north it goes is the projection onto the celestial sphere of the tropic of cancer.

Is there a name for it? It parallels the celestial equator at 23.5 deg declination.

**Tags:** declination, ecliptic
> **Comments:**
> **username_1**: I'm having a hard time thinking of any reason such a marker would be of any interest in the sky. The equator is the zero plane, so the projected tropics would just be, well, the 23.5 degrees line.  
> **username_0**: Yeah, well, I pay attention to stuff other people don't care about. When I was a kid, I turned stuff over to see what's underneath, and took stuff apart to see how it works.  It's a curse from God.  
> **username_2**: In sundial terminology, the same names are used for the declination circles as the corresponding latitude circles. https://sundials.org/index.php/teachers-corner/sundial-construction/200-armillary-sundial.html  
> **username_3**: An Armilary Sphere (usually) has rings to denote the celestial equivalents of the these.  The Wikipedia entry has an image with many of the parts labeled.  It just calls them "Tropic of Cancer" and "Tropic of Capricorn".  You might try digging deeper.  https://en.wikipedia.org/wiki/Armillary_sphere  

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## 1 answers

### Answer by username_4 on 2024-06-24. Score: 2 | Accepted answer

I would guess: No. The tropic of Cancer and tropic of Capricorn make sense on the Earth's surface, because the Earth is "rotating underneath" (in an Earth-centered view), so the ecliptic "gets smeared" into a band between the tropics. However, the ecliptic is "stuck to" the celestial sphere and doesn't "get smeared" as it rotates in step with the sphere.

Sorry for putting things in quotes - hope you get the idea, but I can't find other words for the ideas, just as I don't think there is a word, or a compelling need for a word, for what you are describing.

> **Comments:**
> **username_0**: >" the ecliptic "gets smeared" into a band between the tropics." ==[  Yes! That answer is wonderful and delightful! Ty!  

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