The Influence of Planets on the Formation of Sun-Spots

TLDR: In this article, the authors investigated the correlation between the position of sun-spots at their first appearance and the heliocentric longitude of the principal planets, using the available data reach back as far as 1874 inclusive, and are to be found in the publications of the Royal Observatory, Greenwich.

Abstract: This investigation deals with the correlation between the position of sun-spots at their first appearance and the heliocentric longitude of the principal planets. The available data reach back as far as 1874 inclusive, and are to be found in the publications of the Royal Observatory, Greenwich. If we neglect the angle between the sun’s equator and the ecliptic, and add the heliocentric longitude of the earth to the longitude of a spot referred to the central meridian, we obtain the heliocentric longitude of the sun-spot measured from the first point of Aries; deducting now the heliocentric longitude of a planet, we obtain the longitude of the spot referred to the central meridian as seen from the planet. Excluding spots near the eastern limb, many of which have been formed on the invisible hemisphere and are brought into view by the sun’s rotation, the first photograph on which a spot appears gives the position of its origin within about 13° of longitude, provided there are no gaps in the daily records. For the reason given, no account has been taken of any spot which is first seen within 30° longitude from the eastern limb. Measured on the projected disc, the excluded portion covers at the equator a width of 2 minutes of arc or about the eighth part of the solar radius. The total number of spots dealt with is 4271.