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Astral Atlas
Wiki concept · Named stars

Regulus

Also called Alpha Leonis · the heart of Leo

The IAU-recognised proper name for Alpha Leonis A, a bright star in Leo.

In this entry

Astronomical identity

Regulus is the IAU proper name for Alpha Leonis A (HR 3982), in Leo. The component letter is part of the official name-table identification.

An Atlas calculation should select this astronomical target, rather than infer identity from a translated phrase such as ‘lion’s heart’.

IAU: Naming Stars ↗

Name and historical record

Regulus is Modern Latin for ‘little king’, a diminutive of rex. The IAU also lists Regulus among names preserved from Greek antiquity, while explaining that many modern star names passed through translation and transmission.

The royal wording is etymological and historical. It is not a warrant for assigning rank, career, or character to a person whose chart contains a calculated event.

Etymonline: Regulus ↗IAU: Naming Stars ↗

Ptolemy’s named comparison

Ptolemy identifies the bright star on Leo’s heart as Regulus and compares it to Mars and Jupiter in I.9. The wording is unusually explicit and so can be retained without guessing the identity.

Its historical status remains limited: it is Ptolemy’s reported planetary-likeness tradition, not a tested causal explanation or a modern timing method.

Ptolemy, Tetrabiblos I.9 ↗

Use in a modern paran result

Use the timeline to identify which Regulus angle occurred: rise, upper transit, set, or lower transit. Then read its partner event and minute separation before comparing dates or locations.

Brady’s modern angle-based frame can sit beside this record. The separately labelled Mars/Jupiter comparison is useful for studying Ptolemy’s vocabulary; it does not replace the tool’s actual event facts.

Bernadette Brady, Fixed Stars, other voices in our astrology ↗

Word origin · etymology

Modern Latin regulus.

The name means ‘little king’, a diminutive of Latin rex; this lexical fact does not prove a doctrine of kingship.

Etymonline: Regulus ↗

How we know · epistemology

Astronomical identification; historical and interpretive records kept separate.

Regulus A is a named stellar component in the IAU table. Ptolemy’s Mars-and-Jupiter comparison concerns the star at Leo’s heart in his own framework, not a modern paran recipe.

IAU: Naming Stars ↗Ptolemy, Tetrabiblos I.9 ↗

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Connected concepts

Read alongside this entry

Terms used in this explanation

These links connect subjects and terminology. They do not establish a shared historical origin.

Sources & provenance

Use the citations beside each section to distinguish a calculation convention, a historical teaching and an editorial example.

Find these sources across the wiki →

  1. IAU: Naming Stars ↗
  2. Etymonline: Regulus ↗
  3. Ptolemy, Tetrabiblos I.9 ↗
  4. Bernadette Brady, Fixed Stars, other voices in our astrology ↗