Tony Beresford sent me a private message today about a newly-discovered object. >Rob McNaught picked up a satellite the other day. >As it was observed for 45 minutes or so, Bill Gray derived an orbit. >The observations and result can be seen at >http://home.gwi.net/~pluto/mpecs/vfmo.htm > >I think the most likely candidate is a Vela satellite. >The latest elements we have on these are [elsets suppressed] >I would choose Vela 5 or 6 or Vela 10. I analyzed the observations and used elcor to determine the following elset. (This is very similar to Bill Gray's elset.) Of course the mean motion is fairly uncertain. 1 99999U 99999A 04117.72300000 .00000000 00000-0 00000+0 0 07 2 99999 38.9343 334.9306 5029213 107.9042 283.8563 0.21171889 02 I obtained elsets for the 12 Vela objects from Jonathan McDowell's archive. I ran my numerical integration program (int3) against many of these elsets and found that Vela 5 is a match. Input elset from 1970: VELA 5 1 01458U 65058A 70216.57361109 -.00000059 +00000-0 +00000-0 0 00008 2 01458 031.7866 172.9731 2320609 230.4169 264.9005 00.21484576042401 Output after 34 years of integration: 04112.59122 I 38.61 N 333.45 Ec 0.49075 W 107.04 MA 310.71 MM 0.214392 04117.26576 I 38.60 N 333.32 Ec 0.49171 W 107.41 MA 310.50 MM 0.214270 04121.93299 I 38.58 N 333.29 Ec 0.49040 W 107.40 MA 310.34 MM 0.213977 So the inclination matches to 0.3 degrees, the node to 1.6 degrees, the eccentricity to 0.01, and the argument of perigee to 0.5 degrees. Consider that an elset in 1982 looks like this: 82117.24338 I 72.63 N 351.18 E 0.26466 W 12.96 MA 352.71 MM 0.213947 And an elset in 1993 looks like this: 93117.44681 I 13.10 N 163.67 E 0.47635 W 223.83 MA 86.61 MM 0.214816 So the inclination has gone to 73 degrees and then to 13 degrees and is now predicted to be within 0.3 degrees of the observed value. Similarly, the eccentricity has varied over a large range and is now predicted to be quite close to the observed value. And the fact that the argument of perigee is quite close is also very significant. And the node matches. So I consider this to be a proper match. Mike McCants ------------------------------------------------------------------------- Subscribe/Unsubscribe info, Frequently Asked Questions, SeeSat-L archive: http://www.satobs.org/seesat/seesatindex.html
This archive was generated by hypermail 2b29 : Wed Apr 28 2004 - 17:59:13 EDT