IOTA/IOTA-ES occultation update for
(146) Lucina / TYC 1875 1417 event on 1999, March 27
visible from north Africa, maybe also south Portugal and Spain
Summary
On the evening of March 27, 1999 will be occulted 10.8 mag star by a 137km asteroid (146) Lucina. This update is based on USNO/Flagstaff and TMO astrometry for asteroid and ACT star position. Considering also parallax of star and new orbit computed the updated path is about 1 path width south of the Goffin's nominal prediction with no significant time correction. Therefore I'm giving here only a shortened version of usual update note and no update chart.
That star has TYCHO quality flag 7 (low), X flag being dubious astrometric reference star and moreover flag indicating uncertaing magnitude. Nominal positional accuracy is 0.08", but recent (233) Asterope occultation in western USA involving star with the same Q=7 and X flags shown that there may be quite a large true error, maybe up to 0.5". The orbit has expected error 0.1" so the main uncertanity is the star position. Observers up 0.5" from the nominal central line may try their chance to see the occultation of main body and all within 1.5" may try to catch the once seen secondary occultation of possible satellite.
GSC flags this star as non-star object with mag 10.6 (approx V), probably because there is a blend with about 13.7 mag (non-GSC) star just 9" west. During possible occultation this will remain visible and will form a couple with 13.7 mag asteroid so the total mag drop may be only 2.2 magnitudes which is still visually observable.
The target star itself is 56" SW of 7.9 mag double star COU898=SAO 77661=PPM 95013 with equal brighness components only 0.2" apart; this will probably complicate the observation a little. It is quite far from bright stars, nearest being 1.7 mag beta Tau (upper horn of Bull) about 6 degrees west of target star.
Calculator(s): Jan Manek---------------------------------------------------------------------------- Jan Manek Stefanik Observatory Private : Petrin 205 Werichova 950 118 46 Praha 1 152 00 Praha 5 - Barrandov |_|_| Czech Republic Czech Republic / \ Internet : jmanek@mbox.vol.cz |-O-O-| --------------------------------------------------------------------U---U---
