ISS transits the Sun (25th May 2010)

Dear friends ... and Kieran,

As I discovered a few days ago, I had a predicted transit against the Sun by the International Space Station. This particular transit was of great interest since it was only at a distance of 432 km away and in contrast to the more typical 700-1000 km distance.

I had a small scare yesterday morning when there was a very slight orbit manouvre and which changed the pass to a grazing transit (0.11 sec duration). Fortunately things were back to normal last night with the transit being right smack through the middle of the sun and with a duration of 0.54 seconds. I had very thin cirrus clouds which adversely impacted the resolution I normally get when pursuing the sun but the experience at 2400mm focal length was a first for me and I now have a priceless baseline level for future opportunities.

The Space Shuttle Atlantis (STS-132) was 23 seconds and one arc-minute behind the ISS and, unfortunately, a simultaneous transit was not possible.

Anyway, I hope you like the result: www.perseus.gr/Astro-Sat-Trans-2010-05-25.htm (the inset is at only 65% of the original).

Anthony.

Brilliant Anthony, an arcminute or so lower and it would have transitted AR11072!
BTW how do you calculate these transits. When I go onto heavens above they just show it wrt the country and not the sky.
Id love to try one of these in Halpha

DG

Hi Dave,

I agree fully with you in relation to an h-alpha capture!

With respect to predictions, I shy away from HA and use one of two alternate methods: (1) CalSky and (2) customized JAVA source.

For CalSky, you can request email alerts to be sent to you as events become available and/or you can check online on a regular basis. You can register a site for yourself and which includes accurate GPS coordinates. Everything else follows.

For the customized JAVA source, it is something that was produced by Thomas Fly and who has since abandoned the email updates. However, the source is now available on Ed Morena's website and which you can download and run locally as per your wishes and needs.

On a similar note, the following may be of interest: www.perseus.gr/Astro-Tips-ISS-Transits.htm .

Anthony.

thanks Ill check them out

DG

WOW!
Great image.
What a back drop. Amazing result sir..