Tom - very nice catch!
Forgive my impertinence but some may not be aware you may need to click on the
Original size version to get the GIF (and see movement). For convenience,
here's a direct link: http://www.pbase.com/polakis/image/161853581/original
Also, what camera do you have that takes 4 seconds to download (at 3x3 no less).
Regards, and good shooting,
Bill Shaheen
Superstition Mountain Astronomical league
-----Original Message-----
From: Tom Polakis <tpolakis@xxxxxxx>
To: AZ-Observing <AZ-Observing@xxxxxxxxxxxxx>
Sent: Sun, Nov 15, 2015 9:13 am
Subject: [AZ-Observing] Near Earth Asteroid 2015 VY105, The Movie
This asteroid was discovered not long before an encounter that would bring it to
within 20,000 miles of the earth. At close approach, it would be around
magnitude 13, and moving at a rate of 2 arcminutes per second. That latter
number would make imaging this object a challenge, since its light doesn't
settle on each pixel for very long. Just by coincidence, the declination of the
asteroid near closest approach as viewed from Tempe would be just south of -5
degrees, in the band with the geostationary satellites.
Over a one-hour
period, I captured the asteroid on ten sets of images, typically done as 10 to
15 images centered around a time when it would be at known coordinates. Here's
one example, showing the asteroid as the fainter streak moving left-to-right,
and a geostationary satellite entering the frame from the right at the end of
the sequence.
http://www.pbase.com/polakis/image/161853581
The images are
binned 3x3 to increase the sensitivity, and each exposure is 5 seconds. The
camera downloads for about 4 seconds before it's ready for the next exposure.
Field of view is 45'x30', so you can see that the asteroid was really
cruising.
As always, thanks to Brian Skiff for alerting me to the event, and
coaching me through the process of acquiring the topocentric
ephemeris.
Tom
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