------------------------------------------------------------------- THE ASTRONOMER Electronic Circular No 1184 1997 Apr 16 18.43UT Ed:Guy M Hurst, 16,Westminster Close, Kempshott Rise, Basingstoke, Hants, RG22 4PP,England.Telephone/FAX(01256)471074Int:+441256471074 INTERNET: GUY@TAHQ.DEMON.CO.UK GMH at AST.STAR.RL.AC.UK WORLD WIDE WEB http://www.demon.co.uk/astronomer ------------------------------------------------------------------- OCCULTATION OF 139 JUEWA BY PPM 127356, 1997 Apr 18/19 Richard Miles, BAA, ARPS Section reports: This large 162 km diameter object is predicted to occult PPM 127356 (V=9.3) located at RA 10h 22m 55s, Dec.+12deg 29' 27" (2000) at 21:44-22:08 UT as seen from the UK and Western Europe on April 18. The maximum duration of the event is expected to be very long, about 30 seconds, and the star should dip in brightness by nearly 3 magnitudes (roughly 10-fold). The event takes place at a relatively favourable altitude (45-50 deg)and the shadow width will be projected over more than 200 kilometers of the Earth's surface as seen from the UK. The most probable mid-time for the event is 21:56 UT. Remember to allow for the 1 hour difference between current time and UT, and start observing the star at 10.44 p.m. local time in the UK. Note that by coincidence a further very favourable occultation of a 7th magnitude star by the same asteroid, 139 Juewa, will also take place 11 days later - details to follow in a further announcement. A successful set of observations of BOTH events would provide 3-dimensional information for this object, which will have rotated 12 times plus an additional 234 degrees by the time of the second event. Good luck with the first! N.B. A finder chart is available on the WWW at: http://www.ast.cam.ac.uk/~baa/139a.gif The Moon will be relatively close (about 12 deg distant) and approaching full so allow plenty of time to locate the target star prior to the event. Estimate the chance of a positive event as seen from the UK as about 25% probable. Guy M Hurst