how long do iridium flares last?

[WayBig]

just seen one same time and location as specified on heavens above, but it was over in a few seconds. Is that...erm..normal? Quite cool, but I was expecting more, or at least longer.

[barkis]

It depends on a number of factors I guess. Their rotational speeds vary quite a bit, so the maximum brightness duration is largely dependent on the spin rate, also the attitude of the satellite must play a part, as it will affect the amount of sunlight directed down to earth.

Perhaps the members who have a big interest in Iridiums will give you more useful information. It is an interesting activity, tracking and imaging the flares as they develop.

Ron.

[LukeSkywatcher]

i have seen 4-5 flares and from start to end they all seem to only last about 10s.

If even that long.

[QldLiz]

have also seen quite a few, and they seem to last about 4-5 sec only.

[Talitha]

The ones i've seen have lasted for about 4-5 seconds... it doesn't seem like a lot, but it's long enough.

[WayBig]

ok, thanks for the replies:icon_salut:. Perhaps I saw a short one, or perhaps I was a few miles from it's centre.

Anyway, after initial disappointment, I've reset my expectations and am now eager to spot some more.

[Peter Drew]

Saw a -7 mag one last night at around 11.20 elevation 35 degrees altitude, direction W. 3.5K's from centre line. Just a few seconds duration but impressive considering the light sky. When the sky is really dark and you have accurate time and position data, it is possible to see the Iridium for some time before and after the main "flare", particularly with binoculars.

[LukeSkywatcher]

I have no perception of time passing so my 10 seconds is probably closer to the 5 seconds mentioned above. Does it depend on location as to how long they last.........i'm 53 degrees N.

[jgs001]

I agree about 5 seconds for the main flare, but I've watched the lead in and lead out tracks for 20 odd seconds before and after the flare (it's quite faint though).

[LukeSkywatcher]

I agree about 5 seconds for the main flare, but I've watched the lead in and lead out tracks for 20 odd seconds before and after the flare (it's quite faint though).

Maybe thats where i got my 20s from. I've caught the lead into a flare a couple of times and always follow them afterwards.

[Ant]

I would agree, the bright part - around 5 seconds. But if you know which way it's coming from, you can watch them for ages.

The first one I saw really shocked me!

Great sight!

Ant

[abumuhannadh]

my first flare was close to sunrise. although it was a -6 flare, it lasted only about 1 and a half second. so i thought thats it, its the longest i can see. so the next time (also a -6 magnitude flare) i was expecting it to be the same, but to my excitement, i found the satellite before even the flare began and followed it, and the flare lasted about 6 seconds, and i could still see the satellite at about magnitute 2 after the flare. this second time was actually after getting dark, so i am guessing the seeing plays an important role for how much you could expect.

[Peter Drew]

Your location does matter, inasmuch as the nearer to overhead the flare is, the brighter it is likely to seem.

[teh_orph]

What can you see when you look through binoculars? I've only ever seen them with the naked eye. I saw a -7 through thick cloud the other night - they can be that bright!

[kev 102 42]

i saw one and it was only 1or2 secs it was very bright..........kev