Sun’s right ascension and declination – pick the comprehensive correct set Which of the following statements about the Sun’s right ascension (RA) and declination (δ) are correct?

Introduction / Context:
Right ascension and declination describe the Sun’s position on the celestial sphere relative to the equator and the vernal equinox. Seasonal motion causes predictable changes in δ and steady eastward progression in RA.

Given Data / Assumptions:

• Standard astronomical year with equinoxes near March 20–21 and September 22–23, solstices near June 21 and December 21–22.
• Obliquity of the ecliptic ≈ 23.5°.

Concept / Approach:
As Earth orbits the Sun, the apparent solar position moves along the ecliptic. RA increases continuously and wraps at 24 h near the vernal equinox direction. Declination reaches +23.5° at the June solstice, 0° at both equinoxes, and −23.5° at the December solstice.

Step-by-Step Solution:
(a) RA behavior: increases 0–24 h over a year → correct.(b) Maximum north declination ≈ +23.5° near June 21 → correct.(c) δ = 0° at September equinox → correct.(d) Maximum south declination ≈ −23.5° near December solstice → correct.Thus, all statements are correct.

Verification / Alternative check:
Almanacs and solar ephemerides list RA and δ values matching these seasonal markers.

Why Other Options Are Wrong:
Since (a)–(d) are all correct, any single-option choice would be incomplete; the comprehensive choice is “All of the above”.

Common Pitfalls:
Mixing up which equinox corresponds to northward or southward crossing; RA increases uniformly while δ oscillates between ±23.5°.

Final Answer:
All of the above