[BAA-ebulletin 00872] Favourable asteroid occultation of 7th magnitude star on 2015 September 29/30

[BAA electronic bulletins service]

Observers are strongly encouraged to try their hand observing the most 
favourable stellar occultation by an asteroid visible from the UK in 2015.

The event will take place between 04:27:00-04:30:00 UT (5.27 a.m. - 5.30 
a.m.) early on Wednesday morning, September 30 when asteroid (275) Sapientia 
passes in front of the 7th magnitude star, HIP 14977 in Aries, close to the 
border with Taurus and Cetus, blocking out the light from the star for up to 
18 seconds. Since the asteroid is 13th magnitude, when the occultation 
starts the star will appear to vanish albeit temporarily - accurately timing 
the disappearance and reappearance of the star will allow us to construct 
the silhouetted profile of this minor planet for the first time and if lots 
of observers monitor the event, we may even detect a companion object if the 
system happens to be a binary asteroid, or discover that the star in 
question is a double. So do please set your alarm and try to observe this 
very rare phenomenon - the more observations we receive, the better; and 
remember, even if the star is not seen to blink out from your location, a 
negative observation is still valuable in helping to define the shape and 
size of the asteroid.

The position of star HIP 14977 is RA(J2000) 03:13:03.2, Dec(J2000) 
+11:16:07. Finder charts and more detailed observing advice can be found at 
the following webpage maintained by Tim Haymes, the BAA's Occultation 
Co-ordinator (N.B. We are also planning to issue a BAA Circular together 
with details of the total lunar eclipse, which takes place the previous 
night):

http://www.stargazer.me.uk/call4obs/NextEvent.htm

The star will be well placed and visible towards the south-west at an 
altitude of more than 40 degrees. Note that a bright moon (93%-lit) will be 
situated some 13 degrees away and so try to shield the telescope/ camera 
from direct moonlight. If clear, the ~150-km wide shadow track is more or 
less guaranteed to pass somewhere across England during the observing 
window. Please report observations to Tim Haymes: tim at stargazer dot me 
dot uk

Thank you and good luck,

Richard Miles
Director, Asteroids and Remote Planets Section

2015 September 15 09:08