Astronomical League Occultation Project
Asteroid occultations
Asteroid occultations, where an asteroid (sometimes visible itself, sometimes not) passes in front of a star, casting a shadow the size of the asteroid onto Earth’s surface.
Attempt and successfully observe, including submission of a report to the IOTA regional coordinator a total of 7 asteroid occultations. At least 1 of these must be a “positive” observation, a second must either be a positive or a negative that constrains other observers’ positive(s). The rest may be “negative” observations that support other observers’ positive observations. The timing of these observations must be referenced to either GPS or WWV universal time. Observations may be either visual or using video/imaging equipment. For 3 of these observations, the asteroid must be bright enough to be visible (in an eyepiece or in the imaging/video equipment), and either a sketch or image of the asteroid approaching and/or receding from the star with an arrow indicating the direction of motion should be submitted.
Total lunar occultations
Total lunar occultations, where the dark leading edge of the waxing Moon covers (or the dark trailing edge of the waning moon uncovers) a star.
Attempt and successfully observe, including submission of a report to the IOTA lunar occultation coordinator, for at least 15 total lunar occultations over at least 5 different dates, at least 1 of which must be for double stars that produce a stepped disappearance or reappearance and at least 3 must be reappearances. Each reported timing may be of the disappearance(s) or reappearance(s).
Grazing lunar occultations
Grazing lunar occultations, where the north or south limb of the eastward-orbiting Moon just grazes a star. The light of the star is frequently seen to wink off and on several times as it is periodically blocked by the mountains of the Moon. The area where these events can be seen may be quite narrow, and a difference in position of only a few hundred yards on Earth can materially change the pattern of disappearances and reappearances observed.
Attempt and successfully observe, including submission of a report to the IOTA lunar occultation coordinator, for at least 3 grazing lunar occultations, at least 1 of which must produce multiple disappearances or reappearances. Each reported timing must be of the disappearance(s) and reappearance(s).
