Mercury Transit 3rd Contact GPS Timing Result

[bamm]

Amateur astronomers Dr. Armando Lee, Bamm Gabriana, and Rochelle Derilo were members of an expedition to Gubat, Sorsogon, Philippines to observe the transit of Mercury.

The objective of the observation was to achieve millisecond accuracy in contact timing of the Mercury transit.

This was done by connecting a Garmin 18 LVC GPS to a KIWI-OSD video time inserter, which is in turn connected to a PC164 CCD camera. The telescope used was an Apex 127mm f/12 Maksutov mounted on an LXD75 AT mount.

The GPS would read the time from multiple satellite atomic clocks; the KIWI-OSD receives the time from the GPS and inserts it into each frame of the video output of the camera.

Upon review of the video, it appeared that 3rd contact happened at about 8:08:48.125 with an error of at most 8 milliseconds.

This image shows the significant frame:
http://www.bamm.gabriana.com/astro/mercurytransit.html

Explanation of the numbers:
00:08:48 is the time in UT
117 milliseconds is the time that exposure of the frame began
133 milliseconds is the time that exposure of the frame ended
69898 is the field number of the frame
By taking the average of 117 and 133, we know that the event happened
at 125 milliseconds plus or minus 8.

We humbly submit the above image for consideration in APOD.

Best regards,

Bamm Gabriana
Marikina, Philippines
14 37 58.2 N
121 05 19.1 E

[bamm]

Please see March 2007 issue of Sky & Telescope, page 71.

Bamm Gabriana
Marikina City, Philippines
http://www.pyxis.astronomy.com.ph/