Ecliptic, Celestial equator and horizon?

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Discussion Overview

The discussion revolves around the concepts of the ecliptic, celestial equator, and horizon, with a focus on understanding their differences and relationships. Participants seek clarification on these astronomical terms and their implications in celestial navigation and observation.

Discussion Character

  • Conceptual clarification, Technical explanation

Main Points Raised

  • Some participants describe the ecliptic as the plane of the Earth's orbit and the path the Sun follows against the stars throughout the year.
  • Others explain the celestial equator as the projection of the Earth's equator onto the celestial sphere.
  • It is noted that the horizon represents the dividing line between the Earth and the sky, with some participants mentioning its tangential nature relative to the observer's position.
  • One participant highlights that the ecliptic is tilted relative to the celestial equator by approximately 23.5 degrees.
  • Another participant raises a new question regarding the precession of the equinoxes, specifically inquiring about the current position of the Aries point (vernal equinox) and its future positions over the next 100 years.

Areas of Agreement / Disagreement

Participants generally provide similar definitions for the ecliptic, celestial equator, and horizon, though some nuances in explanation exist. The later inquiry about the precession of the equinoxes introduces a new topic that remains unresolved.

Contextual Notes

There are potential limitations in the understanding of the precession of the equinoxes, as the discussion does not delve into the mathematical or astronomical details necessary to address the participant's question about the Aries point.

atomqwerty
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Hi, I think I have I little misunderstood about these three concepts:
Ecliptic
Celestial equator
Horizon


Can someone explain me the difference between them, specially between the second and the third ones?

Thank you

carlos
 
Astronomy news on Phys.org
The ecliptic is the plane of the Earth's orbit. From the Earth, it would be the path the Sun follows against the background of the stars during the year.

The celestial equator is simply the Earth's equator projected onto the background of the sky.

The horizon is the dividing line between Earth and sky.
 
Ecliptic is the path the Sun follows as seen on the sky which is tilted to the equator by about 23.5 degrees.

Celestial equator is the projection of the Earth's equator on the celestial sphere.

Horizon can be considered as a plane tangential to the position of the observer. This is also at an angle with the celestial equator which is equal to the axial tilt.
 
thank you all
now the biggest doubt I have is the precession of the equinoxes, i mean... where is the Aries point (vernal equinox) right now? and next year? and within 100 years?
 

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