10 Geosyncs brightening at shadow entry
Mike McCants (mikem@fc.net)
Thu, 7 Oct 1999 12:17:21 -0500 (CDT)
Last night Ed Cannon and I saw about 10 geosynchronous objects
going into the Earth's shadow over a period of about 2 1/2 hours.
Observations were from BCRC: 30.314N 97.866W
The brightest was 23915 (96 35A) Intelsat 709. It was about magnitude 4.
Ed could see it with his unaided eye, but it was difficult for me.
Over the span from about 9PM to 11:30PM CDT Oct. 6 (0200 to 0430 Oct 7 UT),
the shadow entry location gradually changed from about RA 0h 44m dec -5.0
(1950 coordinates) to 0h 37m -5.0. During this time this place in the
sky rose from about alt 21 azi 109 to alt 44 azi 135. Since our observing
site is west of Austin, the sky brightness is fairly bad to the east.
Binoculars, a 12x80 finder, and my 8 inch Dob were used.
The object 23536 (95 16A) Brasilsat B2 was about 6th magnitude, but
"dipped" in brightness alternately to 7th or 9th every 2.07 seconds.
The object 23199 (94 49A) Brasilsat B1 22 minutes behind it showed
similar behavior. It was magnitude 6 and dipped to magnitude 9
every 2.02 seconds.
Ed Cannon saw an unknown flashing geosync about 10:16PM (3:16UT) about
RA 1h 5m, dec -10.3 degrees (1950). Apparently it went into the shadow
soon after this. He said it flashed to about magnitude 6 about every
45 or 50 seconds.
I have rewritten HighFly in a special form that generates only eclipse
predictions. It can be found as http://www.fc.net/~mikem/ftp/highecl.zip.
It generates predictions only when an object is between 2.5 degrees
outside to 0.5 degrees inside of the Earth's shadow.
The output below shows 21 objects that went into the shadow over a 3 hour
period. Now all I have to do is figure out exactly which ones we saw.
Mike McCants
(These predictions are 1950 coordinates.)
*** 1999 Oct 6 Wed evening *** Times are CDT
Hrs Min Alt Azi Mag Hgt R A Dec Range
19217 PAS 1 (Panamsa 88-051C 329** .2 ELDY 2 M2 -3
9 10 23 111 8.6 22243 0 34.8 -5.0 24375 2.1
9 15 23 111 8.6 22243 0 39.8 -5.0 24375 1.0
9 20 23 111 8.6 22243 0 44.8 -5.0 24375 .0
20705 TDF 2 90-063A 3.5** 5.1 ELDY 2 M2 -1
10 45 41 131 13.2 22653 0 31.9 -5.9 23844 1.5
10 50 41 131 13.2 22652 0 36.7 -5.9 23842 .5
10 55 41 131 13.2 22650 0 41.6 -5.9 23840 -.3
20872 SBS 6 90 91A 26 M 3.5 ELDY 4 M2 -2
11 5 46 139 11.5 22245 0 21.2 -5.2 23197 2.5
11 10 46 139 11.5 22245 0 26.2 -5.2 23197 1.4
11 15 46 139 11.5 22245 0 31.2 -5.2 23197 .4
22314 TDRS F6 93-003B 1000**-1.0 ELDY 4 M2 -3
9 20 25 113 7.4 22246 0 36.0 -5.7 24299 2.1
9 25 25 113 7.4 22246 0 41.0 -5.7 24299 1.1
9 30 25 113 7.4 22246 0 46.0 -5.7 24299 .1
23051 GOES 8 94 22A 13 M 3.5 ELDY 2 M2 -2
11 10 47 140 11.5 22252 0 23.0 -5.4 23194 2.1
11 15 47 140 11.5 22252 0 28.0 -5.4 23195 1.1
11 20 47 140 11.5 22252 0 33.1 -5.4 23195 .1
23199 Brasilsat B1 94-049A 11** 3.9 ELDY 5 M2 -2
10 50 44 134 11.9 22245 0 24.4 -5.2 23316 2.2
10 55 44 134 11.9 22245 0 29.4 -5.2 23316 1.2
11 0 44 134 11.9 22245 0 34.4 -5.2 23316 .1
23413 ORION 1 94-079A 82** 1.7 ELDY 4 M2 -2
8 40 17 106 10.4 22247 0 36.0 -4.9 24771 2.2
8 45 17 106 10.4 22247 0 41.0 -4.9 24771 1.1
8 50 17 106 10.4 22247 0 46.0 -4.9 24771 .1
23426 LUCH 94-082A 8.0** 4.2 ELDY 2 M2 -3
10 5 33 122 12.4 22252 0 36.1 -6.3 23843 1.6
10 10 33 122 12.4 22252 0 41.1 -6.3 23843 .7
10 15 33 122 12.4 22252 0 46.1 -6.3 23843 -.2
23536 BRAZILSAT B2 95-016A 21** 3.2 ELDY 5 M2 -3
10 30 40 128 11.3 22244 0 27.2 -5.1 23487 2.2
10 35 40 128 11.3 22244 0 32.2 -5.1 23487 1.1
10 40 40 128 11.3 22244 0 37.2 -5.1 23487 .1
23571 Intlst 7F6 95 23A 23 M 3.5 ELDY 7 M2 -3
9 45 30 117 11.7 22247 0 34.7 -5.0 23982 1.6
9 50 30 117 11.7 22247 0 39.7 -5.0 23982 .5
9 55 30 117 11.7 22247 0 44.7 -5.0 23982 -.5
23764 PAS 3R 96-002A 32** 2.7 ELDY 3 M2 -2
9 5 22 110 11.2 22248 0 37.7 -4.9 24476 1.6
9 10 22 110 11.2 22248 0 42.7 -4.9 24476 .5
9 15 22 110 11.2 22248 0 47.8 -4.9 24476 -.5
23915 INTELSAT 709 96-035A 116** 1.3 ELDY 8 M2 -2
9 30 28 114 9.6 22246 0 33.1 -5.0 24126 2.1
9 35 28 114 9.6 22246 0 38.2 -5.0 24126 1.0
9 40 28 114 9.6 22246 0 43.2 -5.0 24126 .0
24714 NAHUEL 1A 97-002B 18** 3.4 ELDY 2 M2 -2
11 0 45 136 11.4 22255 0 26.5 -5.1 23271 1.6
11 5 45 136 11.4 22255 0 31.5 -5.1 23271 .5
11 10 45 136 11.4 22255 0 36.5 -5.1 23271 -.5
24819 INMARSAT 3-F4 97-027A 25** 3.0 ELDY 4 M2 -3
9 45 31 118 11.2 22251 0 30.4 -5.0 23941 2.4
9 50 31 118 11.2 22251 0 35.4 -5.0 23941 1.3
9 55 31 118 11.2 22251 0 40.4 -5.0 23941 .3
24891 PAS 6 97-040A 16** 3.5 ELDY 4 M2 -2
9 5 22 110 12.0 22244 0 37.0 -5.0 24465 1.8
9 10 22 110 12.0 22244 0 42.0 -5.0 24465 .7
9 15 22 110 12.0 22244 0 47.0 -5.0 24465 -.3
24916 PAS 5 97-046A 4.0** 5.0 ELDY 5 M2 -3
10 5 34 121 13.2 22284 0 33.6 -5.0 23805 1.4
10 10 34 121 13.2 22284 0 38.6 -5.0 23805 .4
25004 ECHOSTAR 3 97-059A 1000**-1.0 ELDY 5 M2 -3
10 15 37 124 7.1 22246 0 28.0 -5.1 23625 2.3
10 20 37 124 7.1 22246 0 33.0 -5.1 23624 1.3
10 25 37 124 7.1 22246 0 38.0 -5.1 23624 .2
25239 Intelsat 806 98 14A 33** 2.7 ELDY 7 M2 -2
8 55 20 108 11.3 22250 0 38.7 -4.9 24615 1.5
9 0 20 108 11.3 22250 0 43.7 -4.9 24615 .5
25371 INTELSAT 805 98-037A 12** 3.8 ELDY 4 M2 -3
9 55 32 119 12.0 22249 0 34.2 -5.1 23875 1.5
10 0 32 119 12.0 22249 0 39.2 -5.1 23876 .5
25516 GE 5 98-063B 38** 2.6 ELDY 6 M2 -2
11 25 49 146 10.5 22247 0 19.2 -5.2 23079 2.3
11 30 49 146 10.5 22247 0 24.3 -5.2 23079 1.3
11 35 49 146 10.5 22247 0 29.3 -5.2 23079 .2
25585 PAS 6B 98-075A 12** 3.8 ELDY 10 M2 -2
9 5 22 110 12.3 22243 0 36.4 -5.0 24456 1.8
9 10 22 110 12.3 22243 0 41.5 -5.0 24456 .8
9 15 22 110 12.3 22243 0 46.5 -5.0 24456 -.2