Iridium Flare Disappointment

[mozzie (Peter)]

hi guys i have been chasing iridium flares for a few years know and heavens above is very accurate at -8 it is very bright and intence seen one through a slighty cloudy night bright enough to have a circular haze around it very impressive keep chasing them there great fun
mozzie

[Paul Hatchman]

Originally Posted by mozzie

hi guys i have been chasing iridium flares for a few years know and heavens above is very accurate at -8 it is very bright and intence seen one through a slighty cloudy night bright enough to have a circular haze around it very impressive keep chasing them there great fun
mozzie

Seconded. We saw a bright one from Bowen Mountain at 4:15 last Sunday morning. It capped off a very pleasant night of observing.

But here is a puzzle for you all. We also saw something at about 4am, going from approximately East to West in the sky. It would flash about as bright as the Iridium flare (mag -5), approximately every 10 seconds or so, for about 6 or 7 flashes in total. It was so bright, I can't believe it was an aircraft, but I've never heard of a satellite flaring more than once.

Any ideas people? I checked heavens above and nothing seems to match for that time.

Cheers.

[cookie8 (Vincent)]

Thanks guys. Its very encouraging to know that Heavens-above is usually accurate. I will stick with it give another go next week. A couple of -8 coming up but may have to travel 5 or 6 km which is nothing. Is Calsky.com more accurate than Heavens-above? Any experience?

[Coen]

Originally Posted by Paul Hatchman

...
But here is a puzzle for you all. We also saw something at about 4am, going from approximately East to West in the sky. It would flash about as bright as the Iridium flare (mag -5), approximately every 10 seconds or so, for about 6 or 7 flashes in total. It was so bright, I can't believe it was an aircraft, but I've never heard of a satellite flaring more than once.

Any ideas people? I checked heavens above and nothing seems to match for that time.

Cheers.

It is probably either a tumbling rocket body or a no longer functional satellite that is now also tumbling.

[WhiteStarLine (Bill)]

Originally Posted by Paul Hatchman

. . . but I've never heard of a satellite flaring more than once.

Hi Paul,

My guess is that you saw a rocket body tumble (instead of spinning around the axis of symmetry it tumbles around the short body axis). When China launched its last manned spaceflight I observed the separation of the payload and rocket body and timed it as it passed i-Carinae at 4 am one September morning. The payload (with 2 astronauts) was steady yet the r/b immediately started tumbling at a 21 second interval. I posted my observations to the SeeSat-L list (http://www.satobs.org/seesat/Sep-2008/0191.html).

The theory of what is going on is explained at http://www.satobs.org/tumble/rottheory.html.

The site also has some pretty serious Iridium resources, including the explanation for how the MMA causes flaring, other flare possibilities and different prediction software routines that use spare constellations. Visit http://www.satobs.org/iridium.html.

Cheers,

Bill

[Paul Hatchman]

Originally Posted by WhiteStarLine

The site also has some pretty serious Iridium resources, including the explanation for how the MMA causes flaring, other flare possibilities and different prediction software routines that use spare constellations. Visit http://www.satobs.org/iridium.html.

Thanks Bill. I'll check out those sites.

[byronpaul (Paul)]

AMAZING !!!!

I saw my first Iridum Flare last night - I actually saw 2.

Checked both heavens-above and CalSKY and both were spot on.

Couldn't believe how easy it was to find and see at -5 and -4.8 mag.

I'm gob-smacked that they have been occurring for many years and I'm only just finding out about them through this new hobby that I've picked up.

Here's to many more

[cookie8 (Vincent)]

Yes I saw & imaged my first iridium flares last night as well. It might not be as bright as -8 mag as predicted but not far off.
Ron & Rob, I finally found the problem of my "disappointed" flare last week.
Silly me! Heavens-Above asked for my coordinates in degree and decimal points but I entered the number of arc minutes after the decimal point instead LOL. No wonder the flare was dim! Attached is my photo last night. Cheers.

[astroron (Ron)]

Well done, you won't stop now looking for them now