Andrew Cooper
Sep 3, 2021    Waikoloa, HI (map)
28cm f/10 SCT, NexStar 11" GyPSy @ 175x
Seeing: 5 Transparency: 6 Moon: 0%

An exquisite binary with a rich yellow primary and a blue companion, βCyg A is rich yellow and over a magnitude brighter, βCyg B is seen 34" northeast of A appearing as a rich blue possibly as a result of contrast with the yellow A companion

Andrew Cooper
May 28, 2006    Gila, NM (map)
46cm f/4.5 Deep Violet

Always a favorite!! a beautiful blue gold pair, 3.0 mag. gold and 5.1 mag. blue separated by 35"

Rev. T.W. Webb
May 19, 1885    Hardwick, Herefordshire, England (map)

One of the finest in the heavens. I have seen the colors beautifully by putting the stars out of focus. Sm. observes that they are actually different, not, as may sometimes be the case, complementary, from mere contrast; an effect which is seen when the bright yellow light of a lamp makes the moon appear blue, and which Schm. witnessed to a remarkable degree at his observatory on Vesuvius during the great eruption of '55, when the sky was as green as bottle glass, and the full moon a lively green through opening in red clouds of smoke and steam. A similar result may take place with some double stars, but not with all, as is proved by hiding the larger star behind a bar in field. Hence artificial lighting is misleading in estimating star colors.

― Celestial Objects for Common Telescopes, T. W. Webb, 1917

Drawings, descriptions, and CCD photos are copyright Andrew Cooper unless otherwise noted, no usage without permission.

A complete list of credits and sources can be found on the about page