Vulcan Revived
Observing a planet inside the orbit of Mercury would be extremely difficult, since the telescope must be pointed very close to the Sun, where the sky is never black. Also, an error in pointing the telescope can result in damage for the optics, and injury to the observer. The huge amount of light present even quite far away from the Sun can produce false reflections inside the optics, thus fooling the observer into seeing things that do not exist.
The best strategy for observations might be to wait for the planet's transit of the Sun's disk, and then observe through a solar filter. A small, round dark spot might be seen moving, as happens regularly with transits of Mercury and Venus.
In 1915, when Einstein successfully explained the apparent anomaly in Mercury's orbit, most astronomers abandoned the search for Vulcan. A few, however, remained convinced that not all the alleged observations of Vulcan were unfounded. Among these was Henry C Courten, of Dowling College, New York. Studying photographic plates of the 1970 eclipse of the Sun, he and his associates detected several objects which appeared to be in orbits close to the Sun. Even accounting for artifacts, Courten felt that at least seven of the objects were real. The appearance of some of these objects was confirmed by another observer in North Carolina, while a third observer in Virginia saw one of them.
Courten believed that an intra-Mercurial planetoid between 130 and 800 kilometres in diameter was orbiting the Sun at a distance of about 0.1 AU. Other images on his eclipse plates led him to postulate the existence of an asteroid belt between Mercury and the Sun.
None of these claims has ever been substantiated after more than forty years of observation. It has been surmised, however, that some of these objects - and other alleged intra-Mercurial objects - may exist, being nothing more than previously unknown comets or small asteroids. Today, the search continues for these so-called vulcanoid asteroids, which are thought to exist in the region where Vulcan was once sought. None have been found yet and searches have ruled out any such asteroids larger than about 60 km. Neither SOHO nor STEREO have detected a planet inside the orbit of Mercury.
Read more about this topic: Vulcan (hypothetical Planet)
Famous quotes containing the word revived:
“In ordinary speech the words perception and sensation tend to be used interchangeably, but the psychologist distinguishes. Sensations are the items of consciousness—a color, a weight, a texture—that we tend to think of as simple and single. Perceptions are complex affairs that embrace sensation together with other, associated or revived contents of the mind, including emotions.”
—Jacques Barzun (b. 1907)