Telescope view of ISS?

[cucmbere]

Hi,

With the week ahead of evening passes what can I expect to see through the scope tracking manually? What mag. and/or FOV do you recommend. I am doing some prep. to help with this inaugaural(for me) event.

Thanks,

Bob.
12" Newt/Dob.
Melbourne.

P.S. What would be angular dimensions(approx.) at close passes?
http://www.iceinspace.com.au/vbiis/images/misc/progress.gif

[Kevnool]

Welcome to IIS Bob.
The situation will be a non event (Visually).
At low magnification you will track a point of light.
At high magnification the odds are against you,I say impossible visually but not photographically where it can be done as seen in the solar system threads.
Cheers Kev.

[bird]

I've heard that the IIS appears about the same dia. as Jupiter, so this might give you some idea of what to expect. It's also moving very fast so I doubt you could track it except at low power.

cheers, Bird

[cookie8]

Hi Bob welcome to IIS
ISS flybys of mag -2 or brighter are always spectacular to watch naked-eye. One cannot manually track and look through the EP at the same time. Even if you you can it only appears as a bright spot at low power. At high power the chance of keeping it within the FOV long enough to see any detail is ZERO.
Its angular size at closest approach is about that of crater Capernicus on the Moon
The best and only way is to swap the EP with a webcam or CCD camera and record a video clip then playback frame by frame.
Enjoy the show!!

[cucmbere]

Ok, this is my obs. of the ISS just a few minutes ago using a 12" Newt/Dob
with 12mm Nagler e.p. yeilding 127X and 37 arcmin FOV.

Through the Telrad I saw the ISS was going to move through the bullseye exactly where the heavens-above website had predicted for my location, so I looked through the eyepiece and along it came, approximately center the FOV. It was moving slow enough (2-3 sec.) for me to see a bright pair of rectangular solar panels and a fainter long thin appendage. I had enough time to move the scope ahead so that it would pass again through the e.p`s FOV. The solar panels looked too bright and washed out the scene if there would be any more detail to be seen.

In hindsight, to use more magnification would require more precise placement in the ISS path and it well just be that there would be just one shot at it but it would also mean seeing more detail.

The Heavens-Above websites finder chart was spot on at placing the satellite path for my location! There will be 2 passes tomorrow evening and with the forecast for a sunny day I think I will try for more magnification.


Bob.

[cookie8]

Hi Bob
You've done very well. You must have had your Telrad perfectly aligned.
Nice ob report. Did you see it tonight?
Cheers

[erick]

Now that is impressive, Bob. How did you go with higher magnification?

[cucmbere]

Hi,

The next morning I was up to see a double moon shadow transit on Jupiter which was impressive. Early that morning a couple of friends of mine and I decided to go on a fishing trip for 3 days to the Murray so I did not get a chance to use my scope on the ISS but we did see the flybys from there(Robinvale). The times and location of the ISS were the same for Melbourne even though Robinvale is approximately 500km north-north west!

As you may well know, Heavens-Above.com diplays a star chart with stars to mag. 6 and a track layer of the ISS. I use that chart in conjuction with a planetarium program, TheSky6 in my case to verify the fanter stars in the E.P. and the exact location of the ISS path. Positioning the scope to the exact spot that the ISS will cross was not that difficult because I knew the track would pass between 2 stars which I have chosen to place the scope.

The heavens above star chart is not too crude because it shows tick marks every 2 degrees of Declination which is like some wide field e.p`s. and in my case with the 12mm e.p.(137x and 37'FOV) I had to zero in the scope which is why I prefer to also use a planetarium program.

I must admit that zeroing in the scope within half a degree or less involves some time and probably luck because there is definately some possibilty of error. This is because of the crudeness of the given star chart on the aforementioned website. Take for example tonights event. The ISS will pass between 2 stars of mag. 3 one third the distance of the more easterly star. These two stars are seperated a little more than 2 degrees but with no reference stars in between the two stars how can it be measured accurately the exact location the ISS will pass?. Or some seconds later down the track it(ISS) will pass within(I guess) 10 arcmin of a mag. 6 star which itself is just 3 degrees of a mag. 1 star so finding it should be easy. That would be a safer bet and a greater chance of seeing it in a higher power e.p. and smaller FOV.

There are many good oportunities. Time will tell.


Bob.

P.S. How was the fishing? Very dissapointing with little to no action!

[cucmbere]

Obs: 18/4/09; 18:44 AEST
Equip: 12" f5,6; Radian 8mm; 205X; FOV 18'

A big cloud moved in right on cue and made naked eye sighting impossible but the scope was already positioned on the reference star(Nu Octantis) and then it arrived on cue, maybe 10 arcmin south.

Verdict: speeding bullet, almost 1 second veiwing time and I was off centre of FOV by approx. 5 arcmin! Bright, square shaped? but clouds probably effected seeing more detail. Even so, I just was not ready for it and my eye moved side to side just trying to get a lasting impression of it.

For comparison a 8mm Ethos e.p. would give a FOV of half a degree which is 6 arcmin. less than the last obs. made with the 12mm Nagler e.p. and 12 arcmin. more than the 8mm Radian e.p. The obs. made with the 12mm was much more comfortable with the larger FOV(36'). It is the amount of time required for the eye-brain to connect to the visual cue that is required for the brain to get a lasting impression.

Since I dont have an Ethos i will use a 20mm Nagler and 2X Barlow yeilding 164X and 0.48 degrees of arc(28,8').


Bob.