Opening the book…
Unless you are unlucky enough to choose as one of your comparison stars Proxima Centauri (whose parallax is much less than an arcsecond), the parallaxes of the comparison stars are not normally something that the asteroid astrometrist has to worry about.
This page titled 11.3.1: Parallaxes of the Comparison Stars was last modified on Sat, 05 Mar 2022 17:43:57 GMT and is shared under a CC BY-NC 4.0 license and was authored, remixed, and/or curated by Jeremy Tatum via source content that was edited to the style and standards of the LibreTexts platform.
The book could not be loaded just now.