International Occultation Timing Association
Link to Steve Preston's prediction
On 2020 Feb 11 UT, the 522.144 km diameter asteroid (4) Vesta will occult a 5.3 mag star in the constellation Aries for observers along a path across Europe, SE Canada, NE USA.
Cloud cover predictions, updated 2/10 7AM CST
Vesta will occult 5.3-mag. star in Aries early Tues. evening (dusk) over Newfoundland; NS??
At 21:59 UT Feb. 11 (5:59pm AST; 6:29pm Newfoundland time, I believe), there will be an unusually bright asteroidal occultation, of 5.3-mag. ZC 454 = SAO 93276 = HIP 14439 by (4) Vesta, at 522 km one of the largest asteroids, that will be visible from Newfoundland (and also eastern Nova Scotia and Prince Edward Is., but in bright evening twilight there), as well as northern Ireland, Scotland, Denmark, the southernmost parts of Norway and Sweden, and northern Poland. The link near the top to Steve Prestonís page gives event details, including finder charts of different scales to help locate the target star. During the occultation, expected to last up to half a minute, only Vesta at mag. 8.3 should be visible (a 3-mag. drop), unless the spectral type K3III star is double (if thatís the case, the events may occur in steps). Due to the starís angular diameter, the disappearance and reappearance should each last about 0.2 second, but longer near the edges of the path. Observations may allow determining the diameter of the star and obtain an accurate astrometric point for Vesta, but we wonít learn anything about the size and shape of Vesta that we donít already know better from NASAís Dawn mission to that asteroid. The current weather forecasts show a large break in the clouds, with different models showing it over different parts of Newfoundland; the current forecast maps can be seen by clicking the blue ďWeatherĒ button. If itís clear, observers in eastern Nova Scotia or Prince Edward Island might be able to observe the event, if they pre-point their telescopes the night before, or if they have quick and robust GoTo capability (I think there will be no chance to observe the event from s.e. Maine, and too difficult in s. New Brunswick and w. Nova Scotia), but the cloud cover forecast maps look quite pessimistic for those areas.
David Dunham, email@example.com