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Riley's Objects #1 & #2 = Frey?
Steve Riley (Buena Vista Observatory, California) photographed what I call his "Object #1" at approx. 07:39 UT on April 1, 2007. By comparison with the 1987 La Silla archive image (on which it is absent), its position (J2000 geocentric coordinates) is
RA 11 26 24.6 Decl -8 57 48.5.
Riley has a new photo which shows what I call his "Object #2" likewise not found on the 1987 archive image. It was taken (midrange of contributing exposures) 05:41 UT on April 24, 2007. Its coordinates (again by comparison with 1987) are
RA 11 26 09.58 Decl -8 55 56.0.
(This second point is corrected for the proper motion of the reference stars but the first point isn't. That's alright, because the relevant stellar PMs are uncertain and of marginal size in both cases, especially the first.)
Using the ephemeris position of the sun at these times, in my above-mentioned computer program, I found that the heliocentric xyz position of these objects differs as though they are the same object which has moved 0.1 AU prograde in an orbit inclined 34 degrees (and moving south) to the celestial equator. Barbarossa's orbit would move it 0.03 AU prograde and is inclined 27 degrees.
There is little remaining discrepancy in the x coordinate. Two-thirds of the remaining discrepancy in the y coordinate is removed by employing my above-mentioned model of the Barbarossa-Frey orbit, but this model does not remove the z coordinate discrepancy. If I do not insist on a circular actual orbit for Frey about Barbarossa, I can move the apparent semimajor axis 37 degrees, until it is parallel to Barbarossa's solar orbit: then, the predicted x, y, and z coordinates of Riley's Object #2 all become roughly what is observed.
Riley uses an 11" telescope [not 16" as I had assumed earlier!]. In Riley's photo I found two different +19.3 stars with stable catalog magnitudes. One of these stars was obvious, and one amounted to a barely discernible pixel overdensity. So, I think the position of Riley's Object #2 is more important than its appearance, which is faint and abnormally small.
Most of the apparent motion between Riley's Objects #1 & #2, is due to Earth parallax. The daily change in Earth parallax is shrinking rapidly, but for the next few days, linear interpolation will predict the geocentric coordinates accurately enough to find Riley's Object, which I think is Frey. When Riley's Object (Frey) is found a third time, then quadratic interpolation can be used to predict the geocentric coordinates.
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