Leonard Kelley holds a bachelor's in physics with a minor in mathematics. He loves the academic world and strives to constantly explore it.
Why Call it the Coleridge Effect?
The first mention of this phenomena comes from Samuel Taylor Coleridge’s ballad entitled “The Rite of the Ancient Mariner.” In it, he mentions that, “while close above the Eastern bar the horned Moon, with one bright Star almost between the tips.” Coleridge based this off of observations he had made in November of 1797 as well as folklore he had read about in Philosophical Transactions, written in 1712 by Cotton Mathen. In said book, it mentions that “there is a Tradition among them (the Indians) that in November, 1668 a Star Appear’d between the Body of the Moon, within the horns of it (Baum 280-3)."
One of the first observations of the effect by an astronomer was William Herschel (discoverer of Uranus), who was hosting a party on May 4, 1783. During the evening, the wife of Dr. Lind was looking at the moon and claimed to see a star inside the disc between the horns of the moon. Herschel tried to explain how this wasn’t possible but finally relented and sure enough spotted it. The effect gradually faded and the occupied star finally disappeared (Holden 71-2).
Another sighting of the effect was on September 18, 1856 when William Stephen Jacob (at the Madras Observatory in India) watched the moon occult 23 Tauri. He thought he saw the star pass over the terminating side of the moon and seemingly move over it, as if it were between us and the moon, of over one diameter of the star, then it vanished (Baum 279).
Our old buddy Airy, famous for his role in the Neptune discovery, mentioned the effect at a Royal Astronomical Society meeting in 1859. Specifically, he recalled when he saw it in 1831 but mentioned that he felt it was an illusion and therefore not meriting investigation. But Sir James South differed, for he found 74 separate instances from 1699-1857 that mentioned the effect. That it was an illusion he did not doubt, but that it was insignificant as Airy felt, he clearly did not agree with, for on February 6, 1821 he witnessed the event when he observes Delta Piscum seemingly move inside the moon’s crescent tips. Interestingly, South was in Britain at the time and no one else there seemed to see it but many people in mainland Europe did (287-90).
With so many different types of telescopes out there, it would be hard to single that out as the main cause of the illusion. And refraction properties didn’t explain it either, for when Mars was similarly near the moon it did not follow the effect at all. And despite having no knowledge of the effect, people have seen the event. Case in point: July 17, 1937 when Colonel C.B. Thackeray saw the occultation of Venus and witnessed the Coleridge effect. Yet he didn’t know about it at the time and thus could not have precursor knowledge guiding his imagination to see something that wasn’t’ there. And people who were scientists and knew about the effect didn’t see it happen during the same occultation (291, 296).
So, what did people see?
La hire in 1699 suggested that the moon was surrounded by a “parasitic light” that made it look longer than it really is, and thus the star is seen through an opaque area. William R. Corliss, an expert on astronomical mysteries, postulated that a number of things could have been responsible including “reflection of sunlight from lunar features, incandescent lunar materials, triboelectric phenomena, piezoelectric phenomena, meteors in the Earth’s atmosphere, mirade action, irradiation, or diffraction.” Doesn’t really narrow anything down (Baum 290, Corliss).
In 1998, Duncan Steel felt that Coleridge may have seen a Leonid meteor shower, which would have happened at the time Coleridge was looking at the sky and in fact in the same general vicinity. C. Stanley Ogilvy was on a similar though process when he postulated that an asteroid could have been swinging by at the time (Baum 285).
Like all good mysteries, the solution remains unknown. Maybe it’s some combo of all of these things. Maybe none of them are right. No recent sightings of the effect have been seen, but who knows? Maybe it will return anyday now…
Baum, Richard. The Haunted Observatory. Prometheus Books, New York: 2007. Print. 279-83, 85, 287-91, 296.
Corliss, William R. The Moon and the Planets: A Catalog of Astronomical Anomalies. 1985. Print.
Holden, Edward Singleton. Sir William Herschel, His Life and Works/Life at Datchet, Clay Hall, and Slough; 1782-1882. J.J. Little & Co., New York: 1880. Print. 71-2.
© 2018 Leonard Kelley