Favourable asteroid occultation of 7th magnitude star

  • albertw
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  • IFAS Secretary
  • IFAS Secretary
8 years 9 months ago #104843 by albertw
Brian Espey in TCD alerted me to the following occultation that some of you may be able to assist with

BAA electronic bulletin
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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):


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

Albert White MSc FRAS
Chairperson, International Dark Sky Association - Irish Section

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