spurious disk

spurious disk

[′spyu̇r·ē·əs ′disk]
(optics)
The nearly round image of perceptible diameter of a star as seen through a telescope, due to diffraction of light in the telescope.
References in periodicals archive ?
27) And he observed the spurious disks of stars with his telescope.
Small telescopes show spurious disks when used to view stars.
the first telescopic observers, of taking those spurious disks for the