☉

In astrology and alchemy (for gold), a variant with a face, 🌞︎, is sometimes seen. This does not occur in astronomy, botany or (obsolete) chemistry.

The shield of the sun god Apollo, with a boss in the center. Medieval replacement of ⟨🜚⟩, the sun with a single ray, which in ancient times had replaced a sun orb surrounded by multiple rays.[1]

Compare the Egyptian hieroglyph ⟨⟩ and the Chinese character ⟨⟩, both of which mean 'sun' and 'day'.

☉

1. (astronomy, astrology) Sol, the Sun.

   A subscript to variables in mathematical equations, such as π_☉ (solar parallax).

   • 1803, Robert Patterson, The Papers of Thomas Jefferson, volume 40 (in English), Princeton University Press, published 2013, page 71:

     Suppose the apparent angular distance of the sun & moon's nearest limbs [...] to be 110°.2′.30″ the app. alt of ☉'s lower limb measuring 20°.40′ and that of ☽'s lower limb 35°.24′

2. (astronomy) solar mass.

   Synonym: M_☉

   • 1939, Oppenheimer & Volkoff, “On Massive Neutron Cores”, in Physical Review, volume 55:

     For masses under ${\displaystyle \textstyle {\frac {1}{3}}}$☉ only one equilibrium solution exists

3. (botany) annual.[2]
4. (alchemy, archaic) gold.
5. (rare) Sunday.

   Refers to the Latin phrase dies Solis, which literally means "Sun's day".

6. (philately) cancellation (with an ordinary post-office cancellation mark).
7. (chemistry, obsolete) hydrogen (Daltonian symbol).

   Technically, this should be red: ☉. May also be typeset ⊙.

• (sun, daytime): ☼
• (sun, gold): 🜚 (obsolete)

• (astronomy): M_☉ – solar mass (as a unit of measurement for the masses of stars)

L_☉ – solar luminosity (as a unit of measurement).

R_☉ – solar radius (as a unit of measurement).

S_☉ – solar constant (as a unit of measurement).

• 
  An abstract variant
• 
  A decorative variant in the Netherlands
• 
  As a symbol for gold
• 
  Symbol on a gold background

• (botany): ⚇ (biennial)
• (astrology): (Solar eclipse)

Planetary symbols
· · · – · – · · · · · · · · · · – · · – · · · · · · · ·

• 𓇳 (hieroglyph for Sun)
• ⊙ (mathematics, computing)

☉

1. (cartography): city center