Open Access
Table 1
PN-size–dependent field radius (Rfield) scaling.
| RPN (arcsec) | Rfield (arcsec) |
|---|---|
| <5 | 3.5 × RPN |
| 5–100 | 2.5 × RPN |
| 100–300 | 1.5 × RPN |
| >300 | RPN + 100 |
Notes. The Rfield is scaled from the PN angular radius (RPN) to balance background star coverage and contamination avoidance.
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