Landon Noll's observation plans

Coordinating Eclipse Observations

I plan to observe the 29 March 2006 Eclipse 80 km south of the Jalu Oasis in Libya near 28º17’53.5”N (28.2982ºN) - 21º34’10.9”E (21.5697ºE).

The duration of totality: is about 04:02 and the Sun Altitude during totality is 62.4º. 2nd contact (start of totality) is about 10:26:49 UTC. 3rd contact (end of totality) is about 10:30:52 UTC.

I will be taking images of Vulcanoids with a Canon 20Da camera.  This camera's 3504 x 2336 pixel CMOS sensor is not covered with an IR filter making the camera more suitable for Red/almost-near-IR photography.  Vulcanoids should be somewhat brigher as one moves from Red, through the almost-near-IR and into near-IR wavelengths.
 
I am currently considering the use a EF 200mm f/2.8L II USM lens.  Because the Canon 20Da has a 1.6 focal length multiplier (due to the size of the sensor relative to 35mm film) I will have field of view that is 6.4º wide and 4.3º high.

My target area will be along the eclitpic (the ecliptici will go horizontally through the field of view) on the west side (to the right) of the Sun.  The center of the right-hand edge of my field of view will be on the ecliptic and 10.5º from the center of the Sun.

If my calculations are correct, the center of the Sun at the middle of the eclipse (10:28:50.5 UTC) will be about RA 00:31:17s Dec +3:22:27.  In order to place the center of the right-hand edge (of the 6.4º wide field of view) 10.5º from the Sun, the center of my field of view needs to be on the ecliptic 7.3º to the west (to the right) of the center of the Sun.  This means that the center of my field of view will need to be near RA 00:04:27 Dec +00:28:55.   

Let me know if you are planning to take Vulcanoid images during this Eclipse, particularly if you are not going to the Eclipse Tent Village. (Two observers located at a number of minutes apart who take similar images of the same position relative to the solar disk have a much better chance of finding a Vulcanoid because they can blink-compare between their images looking for rapid Vulcanoid motion.) I would like to coordinate with you so that we can do a time compare of our two images.

 

Submitted by chongo on Mon, 2006-01-23 02:01.

The 4.3º image height as stated above was calculated using the field of view calculator.  The actual image height is only slightly smaller.  Based on my Canon 20Da field of view  measurements, the field of view is 4.246° ± 0.01°, well within the precision of the field of view calculator.

Submitted by david on Sat, 2005-11-26 10:21.
You say that your 20Da's CMOS sensor is 3504 x 2336 pixels. At 6.4º wide and 4.3º high that comes to about 6.6 by 6.6 arc seconds per pixel. Is that going to be a problem?
Submitted by chongo on Sat, 2005-11-26 11:48.

I am not sure if 6.6 arcsecondi pixels will be a problem.  Based on the star charts, density of known objects outside of the solar system (stars, galaxies, etc.) down to magnitude +15.0 is not too high.  My field of view passes through the spring equinox (where the ecliptici and the equator meet) which is not a rich star field, so I don't think I would have problems distinguishing between a 15th magnitude star and a Vulcanoid for example.

I mention 15th magnitude as just an example.  I have not yet determined how faint the 20Da IR sensitive CMOS system can image during the eclipse.

One potential disadvantage for such a large pixel size is that determining the position of an object of interest will be less exact.  I hope that if I can pair up with another observer who at a location far from my Libya observing site, then the pair of our images will help establish longer baseline that will make finding the object again easier. 

What do other people think?  Is 6.6 arcseconds square per pixel to large? 

chongo (Landon Curt Noll - http://www.isthe.com/astro.html) /\oo/\

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