FLARE of Iridium 97- 30 C = 27838 and other obs.

Kurt Jonckheere (kjonckheere@unicall.be)
Sat, 6 Sep 1997 11:09:11 +0200

Clouds moved away just in time yesterday evening, and the first Iridium
I tried (97- 30 C = 24838) started brightened till mag -5 !  A magnificent
sight.

97- 30 C 97-09-05 20:22:47.3 KJ                       flare to mag -5


                 Sat    Sat     Sun    Flare   Obs    Sun Phase   NORAD #
   UT            Dir  AZ  EL   AZ  EL   Dur  Mag       
20:22:47 09/05/97  S  077 46    ?   ?   10    -5   KJ    50       24838
max EL was 46
Evolution of the magnitude :
20:22:30.3  mag +2
20:22:47.3  mag -5
20:22:58.4  mag +3

97- 30 D = 24839 came over 10  minutes later in an analog orbit, 
but with a maximum EL of 55.  It brightened only to mag +3 near its
max EL.

Seems that the condition for negative flare are rather strict.

observing place was : 51.2344 N, 4.2656 E, O m ASL


Some other observations :

78- 18 B 97-09-05 21:56      KJ  195.3 0.1  62  3.150
UME 2, nice sharp flashes
87- 49 B 97-09-05 21:33      KJ  103.8 2.0   6 17.3   AA, mag+4->inv
92- 12 B 97-09-05 21:47      KJ  228.6 0.2  34  6.72
93- 61 A 97-09-05 22:11      KJ   74.6 0.2   8  9.32  F'fffF', prim dm at end
SPOT, four flashes during one period, primary flash brightest, becoming
brighter during pass, double primary maxima at the end (two sharp flashes
after each other).
95- 32 B 97-09-05 21:41      KJ  298.8 5.0   3 100    N?
96-  4 B 97-09-05 22:05      KJ  211.3 1.5   4 52.8
97- 30 A 97-09-05 21:09      KJ                       mag max +4
97- 30 B 97-09-05 20:48:17.4 KJ                       mag max +4
97- 30 C 97-09-05 20:22:47.3 KJ                       flare to mag -5
97- 30 D 97-09-05 20:31:26   KJ                       brightening to mag +3
97- 30 F 97-09-05 21:17      KJ                       S, mag +6.5

Happy observing,

Kurt J