Summary of the
Occultation of SAO 108610 by 25 Phocaea
October 3, 2006
00:52:08.90 UT (first
October 2, 2006 at 8:52:08.90 EDT
d 00 m 24.0 s North
d 07 m 06.0 s West
Altitude: 158 m
+ 51 km from the
predicted path (west)
Newark, New York
10" LX200GPS at f/6.3 using PC164C gain modified video camera
Recorded by Brad Timerson
Predicted path of occultation from Steve Preston
Approximate observatory location shown just below Lake Ontario to the
west of the predicted path.
is a low-resolution video clip of the event from YouTube
The video starts a few seconds before the WWV time signal at 00:52:00
which can just be heard.
First disappearance occurs nearly 9 seconds after that time signal.
Watch as the star/asteroid combination dim to the magnitude of the
Then the star reappears, disappears, and reappears in rapid succession.
This looks like a GRAZING occultation by an asteroid!
Graph produced from LiMovie
analysis of the Occultation
first disappears at 00:52:08.90 UT
Stays hidden for 102 video
frames - 3.40 seconds
Reappears for 14 frames -
Disappears for 9 frames -
Reappears for good at
Profile resulting from analysis
in OCCULT software
lines show where the star never disappeared (lines top to bottom)
and where the
star was hidden by the asteroid for varying durations at various
Notice chords 16
and 17, mine. You can compare them directly with the graph
above to see how
the star was blocked by the asteroid, reappeared for a brief time,
and was then
blocked again before the event finally ended.
Below is one person's (Richard Nugent) idea of how the asteroid
might have looked if we could have actually seen it.
Notice the gap
in the upper right side.
presentation to an astronomy group a few weeks after the event,
one of the other
observers, Guy Nason from Toronto, Canada, gave
the gap a name.
It is now known as "Timerson Gulch" in the literature.