Hi all,

used Guide8 and fresh elements from IAU MPC to find Near-Earth asteroid 2002
NY40 last night at mag 12.6 or so. We had rather shitty conditions with fog and
clouds moving by, but Guide helped me find it.

Anyway, when plotting the asteroid's position for my coming local midnight (22
UT), I notice that the asteroid's symbol (X) and the Trail I made do not match.
The starting point of the trail and the asteroid symbol's position differ by an
amount of 2.6 minutes of arc with the astroid symbol offset in PA ~260
(South-West-West). Not a lot for sure, but I still find it rather odd that the
program plots the same data in different location. As the asteroid brightens and
speed up it should be easily identified, and the offset is minor, but I'm
curious still.

A fellow amateur in Norway use one of the competitor programs and he found that
it used geocentric coords for the trail and "on-site" coords for the symbols.
Turning "Use geocentric coords" on in Guide move the symbol to the other side of
the trail, however, so I suspect the reason is to be found elsewhere.

Best regards,

Arild Moland :)

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