THE ASTRONOMER Electronic Circular No 789 1993 Nov 16 20.55UT Ed:Guy M Hurst, 16,Westminster Close, Kempshott Rise, Basingstoke, Hants, RG22 4PP,England. Telephone/FAX(0256)471074 Int:+44256471074 TELEX: 9312111261 Answerback: TA G TELECOM GOLD: 10074:MIK2885 GMH at UK.AC.RUTHERFORD.STARLINK.ASTROPHYSICS STARLINK: RLSAC::GMH GMH at UK.AC.CAM.ASTRONOMY.STARLINK STARLINK: CAVAD::GMH ------------------------------------------------------------------- OCCULTATION OF SAO 158379 BY JUPITER Marcel Wilmet, Mariembourg, Belgium faxes: This event will take place on 1993 November 29 (morning) and the visibility area should include North-West Europe (twilight), North-West Africa, the Canary Islands (twilight) and North-West Brazil. The following information has been made available from IOTA: SAO 158379 = HD 123523 = Hipparcos Input Catalogue star 69092. RA 14h05m48.0s DEC -11 35'34" [1950] 14 08 29.0 -11 49 46 [2000] Spectral type: A2 (white star) Magnitudes: V=6.8; B=7.0. Apparent diameter: 1.6 10-4 arc sec i.e. 740 metres at the distance of Jupiter. Relative Velocity (geocentric): 37 km/s Closest approach (geocentric) to Jupiter's centre: 4.7" NNE At: 6h48m54sUT Occultation duration (geocentric): 3700 seconds Notes: This stellar occultation by Jupiter will begin during the totality of the next total eclipse of the Moon! The disappearance and reappearance phenomena will be progressive, because of the refraction of the stellar light in the 'thermosphere' of Jupiter, within the rarefied hydrogen-helium gas, 300km above ammonia clouds. Strong chromatic scintillation of the star is expected, due to Jovian atmospheric turbulence along the ray path. Editor: The BAA Handbook [1993] quotes immersion at 6h19mUT and emersion as 7h19mUT for a geocentric observer. At Greenwich immersion occurs at an altitude of 140, while emersion takes place during morning civil twilight. The elongation from the Sun will be 33 degrees.