The regular orbs for Puto have been what the rbs have been for the other planets, except maybe the luminaries (although not everyone uses wider orbs for luminaries). It depends on what orbs you prefer to use. Some people use pretty generous orbs, others not so much.Some variations of orbs as I've observed:
Conjunction: 5-10 degrees
Trine: 3-7 degrees
Sextile: 2-5 degrees
Square: 3-7 degrees
Opposition: 3-10
Myself, as a guiding rule (with exceptionwhen deemed necessary):
Conjunction: 8 degrees
Trine: 5 degrees
Sextiles: 3 degrees
Squares: 5 degrees
Oppositions: 8 degrees
I usually allow a wider orb (+2) when one of the planets is a luminary, a singleton, chart ruler or is stationary.
A couple of other thoughts about orbs for Pluto:
- Pluto probably ought to be thought more as a binary body because its satellite is nearly the same size. Also Pluto and Charon are in complimentary orbit around *each other* rather simply Charon orbiting around Pluto (techincally it's called "rotation" and they both keep the same face toward each other, like two dancers in a waltz) - this suggests that neither is the "dominant" but a case of two bodies so intertwined they represent one energy.
If thought as a binary body, this could explain some of the oddities with Pluto, as well as it's unique intensity (since it's the only binary body in our solar system we know of). Furhermore, the myth of Pluto does also presents a duality, through transformation, of death and rebirth, which can be seen as represented by the binary Pluto-Charon body.
- Pluto's "demotion" was based largely on it not having it's own orbit (it crosses Neptune's orbit at certain points). At certain points of its orbit when it crosses Neptune's orbit, Pluto is actually closer to the Sun than Neptune. Ina strtology I thin this is significant - see it as Pluto's way of "weaving" itself into our solar system, again in its own unique way.
Suffice to say (again) Pluto is unique, and astrology, being far more of an intuitive science than anstronomy, is much more sensitive to the very real impact such a unique energy can have.