Iridium flares, 30 Aug 97

Ed Cannon (ecannon@mail.utexas.edu)
Fri, 26 Sep 1997 01:20:58 -0400

Late Iridium flare report.  Mike McCants and I were observing at BCRC, 
Austin, Texas:  30.314N, 97.866W, 280m; August 30, 1997, UT (8/29/97 
local time).  Where I don't have the time of maximum flare, I've used 
an approximate time in order to get the approximate solar azimuth and 
elevation.

NORAD  __date__  __time__ Dir azI eI  azM eM  azS _eS Phs  Dur Mag Obs  COSPAR

Iridium 5:
24795  97-08-30  02:09:40  S  145 31  083 51  291 -16 146  ... -2  E/M  97020D
(Data thanks to Mike, who noted time of max, which might have been -3.)

Iridium 6:
24794  97-08-30  02:18:--  S          084 64  292 -18          +2  E/M  97020C
(I don't have the time of maximum flare.)

Iridium 7 (no flare):
24793  97-08-30  02:27:40  S          085 81  294 -20           ?  E/M  97020B
(We tracked Irid. in Mike's 8" scope; at given time saw UNID in field.)

Iridium 8 (no flare):
24792  97-08-30  02:36:--  S          266 81  295 -21          +6? EdC  97020A
(My only note was that I tracked it in my 7x50 binocs.)

Very late report format suggestions (many apologies to Ron!): one space 
only between fields (It does that on the hypermail archive anyway; all 
extra spaces are lost -- but see further note on this below.); four 
characters for year (Y2K); only 1 char for Direction; 4 chars for 
Observer(s) (E.g., Sue and I saw one, and Mike and I saw another.) or 
that exact location number that some people use; 2 chars for Iridium 
number.  This totals only 75 characters, e.g.:

NORAD ...date... ..time.. D azI eI azM eM azS elS Phs Dur Mg Obs. COSPAR IR 
24795 1997/08/30 02:09:40 S 145 31 083 51 291 -16 146 ... -2 ECMM 97020D 05 
........10........20........30........40........50........60........70.....
123456789 123456789 123456789 123456789 123456789 123456789 123456789 12345

I realized (last of all?) that the Sun's azimuth reveals AM or PM....  
So, if the observer doesn't get an exact value for that, the values 90 
for morning and 270 for evening could be used.  (I understand those 
directions are very rough approximations in winter and summer for high 
latitudes.)

Are slashes okay in the date?

I really do think that for *Iridium* flares, the only identifier needed 
for the satellite is "i4, i15, i26, i37," etc., or something like that, 
with a table of correspondence available that links those to NORAD and 
COSPAR.

(Note on the hypermail archiver(s): could it/they could be changed to 
simply enclose the entire body of all messages in <PRE></PRE> tags? 
That would fix the layout problems on the hypermail archive that are
caused by the removal of all extra spaces and the use of proportional 
fonts.)

Theoretical Iridium flare question:  Since they may flare to -8 and
apparently always flare opposite the Sun, what are the chances -- if
any! -- of observing a flare while the Sun is above the horizon 
(especially if they prove to be reasonably predictable)?

Ed Cannon
ecannon@mail.utexas.edu
Austin, Texas, USA
30.3086N, 97.7279W, 165m