Satellites?

[roddz (Rodd)]

While photographing the Southern Cross I had something transverse my pic. Could it have been two satelites next to each other?

Any ideas?

Pic was taken at the Vic South Astro camp last weekend.
36° 27.3' S 141° 40.1' E. 150 metres above sea level

16 10sec exposures between 2.43am and 2.48 am on 31/10/2011

It was moving right to left and downwards.
Note that the pic needs to be tilted about 45 degrees to the left to be in the correct orientation. The brightest star is Acrux.

[theodog (Jeff)]

Funny that,
I just finished reading and replying to this,

http://www.iceinspace.com.au/forum/s...ad.php?t=79118

and now this.

Unless they were planes it is quite possible they are satellites. They do seem bright for satellites.

Nice image.

[roddz (Rodd)]

They weren't that bright, couldn't see them visualy!

[theodog (Jeff)]

Sorry Rodd,
What was I thinking?

You can work out the brightness from your image. It seems they were about the same mag as the 5th star in Crux at their brightest. This would make them difficult to see.

Also the broken trail threw me untill I realised it was a stacked image.This could be used like a rotating shutter.
From this you may be able to work out the approx. period and thus the approx. altitude. This and the direction may lead to an identification.

[roddz (Rodd)]

Did a quick calculation.
What ever they were moved about 15degrees in 2'44",
Giving an orbital time of 63minutes.
I believe this is impossible, as I think to orbit the earth in 63 minutes they would have to be 1100metre below ground level!! so can't be satellites.
Must have been two planes in formation.
I'd love it if someone could check that I've measured and calculated correctly.
First exposure started at 2:43"58'
Last exposure started at 2:47"50'

Thanks Rodd

[firstlight (Tony)]

Hi, my back of ther envelope calculations agree with yours regarding orbit period, I didn't use your figures, but did a rough calculation based on Crux). Have no idea about the orbit height. Isn't LEO about 90 minutes?

[El Paso Eric (Eric)]

If you have the exact time of the pass, try looking in Calsky.com. I've identified a couple satellites that way, including a tumbling Iridium that I accidentally captured.