observing geostationary sattelites

[bartman (Bart)]

Just wondering if we ( as AA) can take pictures of geo stationary satellites.
I have googled and found only star trail like pics.
However there are pics of the ISS and Shuttle by AA's.
Are they to small?
Just curious.......
Bartman

[Virgs]

To take a photo of a one, you need to turn your tracking off. The stars will trail and the geos will be the point sources of light in the frame assuming you are pointing in the right direction. As for detail, no they are to far away and too small to be resolved by normal equipment

[sheeny (Al)]

Bart,

The shuttle and ISS are only 300 to 400 kms above the earth in orbit.

I can't remember the height of the geostationaries off the top of my head but it is a lot higher (of the order of 10's of thousands I think), so they just aren't resolvable in amateur gear. That's why you'll only see the "star trail" like shots.

Al.

[mithrandir (Andrew)]

Originally Posted by sheeny

Bart,

The shuttle and ISS are only 300 to 400 kms above the earth in orbit.

I can't remember the height of the geostationaries off the top of my head but it is a lot higher (of the order of 10's of thousands I think), so they just aren't resolvable in amateur gear. That's why you'll only see the "star trail" like shots.

The "magic" altitude - 22,236 miles (35,786 km) - give or take a few metres.

[sheeny (Al)]

Thanks Andrew!

I knew someone would come up with it.

So roughly 100x further away (therefore smaller)...

Al.

[Greenswale (Wren)]

Visually observed two of these, in 'close' company from Snake Valley in the early hours of Saturday morning.

They were apparent because they flashed like very dim aircraft lights, about every nine seconds as roughly measured by Ken. Flash probably due to satellite spin with solar panels catching the early morning sun? And yes, the stars passed them by.

Location was betwen Mars and Virgo at about 3.00am, 16 Jan 2010.

[koputai (Jason)]

As Wren says, it can be done. I observed one (initially bt accident, and thought I must have seen a ufo!) for around 45 minutes back in the late 80's through a Tasco 60mm Alt/Az refractor. I was looking at something else, and noticed a small flashing object in the FOV. Over the next 45 minutes or so it stayed stuck there in the FOV whilst the stars drifted past. I haven't tried to spot on on purpose though.

Cheers,
Jason.

[citivolus (Ric)]

Geostationary satellites which have gone out of commission for one reason or another will often be tumbling in their orbits, hence the pulsing. Also, at the right time of year, geostationary satellites can flare, making them visible temporarily with the naked eye.

Here is an interesting page:

http://homepage.usask.ca/~ges125/rasc/Geosyncs.html

As an item of note, due to geometry, geostationary satellites tend to plague M42 for many northern hemisphere photographers. For us they shift about 10 degrees north, hanging out around +4 to +6 degrees north declination (see http://www.claysturner.com/dsp/astro1.pdf )

We had one geostationary visible at QLD Astrofest this year on at least 3 successive nights, flaring visually about every 15 seconds for about 15-20 minutes.

Regards,
Eric

[bartman (Bart)]

Thanks for the info guys!!!!

i guessed as much that they would be to far up!

Eric I actually have seen faint satellites cross through or around M42 on a couple of occasions. I'm guessing there not the geostationary ones, as they passed the star not the other way around.

Cheers
Bartman