A planet too close to the Sun is to be seen by the naked eye, roughly 15 degrees, is said to have its qualities hidden or concealed. They are impotent unless mitigated by other factors. A planet in Domicile, Exaltation. or Bounds is said to be In the Chariot and is unaffected.
Hellenistic Astrology by Chris Brennan Astrology Hellenistic Astrology Planets Heliacal Rising and Setting In the Heart of the Sun