What is an Occultation?
An occultation occurs when a solar-system body passes in front of a more distant object (e.g. a star or another solar system body), partially or totally hiding the more distant object and momentarily blocking its light. Each occultation can be seen only at the right time and from a limited part of the Earth.
On the night of 1st and 2nd September 2016, the asteroid 4149 Harrison will occult the 5.9 magnitude star HIP 5594. This star is bright enough to be well visible through binoculars or small telescopes.
This event is predicted to be visible from Malta at 22:19 UT (00:19 local time). During the occultation, the star is expected to disappear instantly during the eclipse for a duration of 1.9 seconds, where the faint (mag.16.8) asteroid will cover the bright star as it revolves around the sun.
The location of the star is RA. 01h 11” 43.4445” DECL -02° 15’ 04.257” in the constellation of Cetus.
Observers are encouraged to observe this event either visually or through digital means. Those who own a sensitive planetary camera (or DLSR in video mode) are encouraged to monitor the star a minute before and after the event with the shortest frame rate possible without considerable deterioration to the Signal to Noise Ratio (SNR). An accurate time reference is essential as to mark the time when the video clip commenced.
Such bright events rarely happen and thus observers are urged to observe this event. Such observations can provide important scientific data on this distant asteroid.
Further details and maps can be obtained through the following link: www.asteroidoccultation.com/2016_09/0901_4149_37413.htm
Another occultation will take place on the same night at 19:59 UT where the maximum eclipse duration will be of 11.3 seconds. The asteroid involved is 159 Aemilia. This time the star occulted will be much fainter at magnitude 10.3v. A chart for this event is also available for reference.
More information on occultations can also be obtained from the IOTA – International Occultation Timing Association website: