After 6 observing sessions it's still not possible to confirm the 2.5-hour period suggested for this object. The amplitude of variation is simply too small to solve for a period.

PRIOR INFO

Skiff Summary

 E.T. Date 2009  5 14.00000000     Elements epoch: 2009  6 18

    Asteroid           Inc  Ecc   S-M     q      RA     Dec    Solar Phase    R     Gal   Ecl  Daily Motn
                                  Axis                         El    Ang            Lat   Lat   RA   Dec 
                         d          AU    AU     h       d        d     d    mag     d     d     s     '   
   5693 93EA            5.1 0.585 1.271 0.527  12.984   6.09   136.7  28.2  17.40  68.9  11.4 -163.  10.8    2.5?  need one night

Orbital Elements:

  5693 1993 EA       |2009 06 18.000|0.585293  |1.271240|  5.0555| 97.1276 |258.7736 | 2000|311.3207  |17.0 | 0.15|   0.00

JPL Ephemeris

**************************************************************************************************
 Date__(UT)__HR:MN     R.A._(ICRF/J2000.0)_DEC  APmag    S-O-T /r    S-T-O    ObsEcLon    ObsEcLat
**************************************************************************************************

 2009-May-14 00:00 *   12 59 03.32 +06 05 16.3  17.80 136.7487 /T  28.1985 191.3341067  11.4261519
 2009-May-15 00:00 *   12 56 20.99 +06 15 48.8  17.82 135.1728 /T  29.2601 190.6329150  11.3235095
 2009-May-16 00:00 *   12 53 41.11 +06 25 50.3  17.84 133.6049 /T  30.3166 189.9452232  11.2162726
 2009-May-17 00:00 *   12 51 03.85 +06 35 20.3  17.85 132.0461 /T  31.3671 189.2717552  11.1046951
 2009-May-18 00:00 *   12 48 29.38 +06 44 18.7  17.87 130.4974 /T  32.4107 188.6131743  10.9890349
 2009-May-19 00:00 *   12 45 57.84 +06 52 45.0  17.89 128.9600 /T  33.4469 187.9700822  10.8695525
 2009-May-20 00:00 *   12 43 29.38 +07 00 39.1  17.91 127.4345 /T  34.4749 187.3430197  10.7465092
 2009-May-21 00:00 *   12 41 04.13 +07 08 01.1  17.93 125.9218 /T  35.4942 186.7324664  10.6201653
 2009-May-22 00:00 *   12 38 42.20 +07 14 50.9  17.95 124.4225 /T  36.5045 186.1388397  10.4907797
 2009-May-23 00:00 *m  12 36 23.70 +07 21 08.7  17.96 122.9372 /T  37.5052 185.5624932  10.3586077
 2009-May-24 00:00 *m  12 34 08.71 +07 26 54.7  17.98 121.4665 /T  38.4962 185.0037127  10.2239009
 2009-May-25 00:00 *m  12 31 57.31 +07 32 09.2  18.00 120.0108 /T  39.4771 184.4627118  10.0869058
 2009-May-26 00:00 *m  12 29 49.55 +07 36 52.7  18.02 118.5704 /T  40.4480 183.9396290   9.9478620
 2009-May-27 00:00 *m  12 27 45.49 +07 41 05.5  18.03 117.1455 /T  41.4086 183.4345291   9.8070009
 2009-May-28 00:00 *m  12 25 45.14 +07 44 48.4  18.05 115.7364 /T  42.3591 182.9474072   9.6645432
 2009-May-29 00:00 *m  12 23 48.52 +07 48 01.9  18.07 114.3432 /T  43.2996 182.4781971   9.5206974
 2009-May-30 00:00 *m  12 21 55.63 +07 50 46.7  18.09 112.9658 /T  44.2302 182.0267785   9.3756583
 2009-May-31 00:00 *m  12 20 06.45 +07 53 03.5  18.10 111.6043 /T  45.1512 181.5929838   9.2296056
 2009-Jun-01 00:00 *m  12 18 20.96 +07 54 53.2  18.12 110.2585 /T  46.0629 181.1766040   9.0827042
 2009-Jun-02 00:00 *m  12 16 39.12 +07 56 16.4  18.13 108.9283 /T  46.9656 180.7773925   8.9351037
 2009-Jun-03 00:00 *m  12 15 00.89 +07 57 13.9  18.15 107.6135 /T  47.8597 180.3950692   8.7869389
 2009-Jun-04 00:00 *m  12 13 26.22 +07 57 46.5  18.16 106.3139 /T  48.7456 180.0293244   8.6383305
 2009-Jun-05 00:00 *m  12 11 55.04 +07 57 55.1  18.18 105.0292 /T  49.6238 179.6798218   8.4893855
 2009-Jun-06 00:00 *   12 10 27.29 +07 57 40.3  18.19 103.7591 /T  50.4948 179.3462022   8.3401980
 2009-Jun-07 00:00 *   12 09 02.90 +07 57 03.0  18.20 102.5034 /T  51.3591 179.0280864   8.1908500
 2009-Jun-08 00:00 *   12 07 41.80 +07 56 03.8  18.22 101.2616 /T  52.2172 178.7250780   8.0414118
 2009-Jun-09 00:00 *   12 06 23.90 +07 54 43.6  18.23 100.0335 /T  53.0697 178.4367656   7.8919430
 2009-Jun-10 00:00 *   12 05 09.13 +07 53 03.1  18.24  98.8186 /T  53.9172 178.1627256   7.7424930
 2009-Jun-11 00:00 *   12 03 57.39 +07 51 02.9  18.25  97.6167 /T  54.7604 177.9025230   7.5931017
 2009-Jun-12 00:00 *   12 02 48.60 +07 48 43.9  18.26  96.4272 /T  55.5998 177.6557128   7.4438001
 2009-Jun-13 00:00 *   12 01 42.65 +07 46 06.7  18.27  95.2497 /T  56.4361 177.4218410   7.2946105

FOLDED ROTATION LIGHT CURVE

The RLC exhibits very little variation during a night's observing session, as well as from night-to-night. The following three "solutions" are the best that I could find.

       
 With an assumed period of 2.5 hours a small variation (~100 mmag, peak-to-peak) appears to exist.



As an alternative here's a slightly longer period solution.




And one more longer period solution. This set of 3 period solutions are the best that I could find.

OBSERVATIONS







Moonlight (15 degrees away) spoiled thse observations.





 
2009.05.25 Simplest interpretation (no variation)


2009.05.25 An alternative interpretation

DISCUSSION