Catching an Iridium Flare

Click on this image to see it full size.

Click on this image to see it full size.

   Last night and this morning brought clear skies, again thanks to the influence of a high pressure system that has lowered the air and dew point temperatures. “Photo op!” I thought. So using ISS Detector Pro, an App on my Kindle Fire HD (7″) I was able to see when and where to look for the next Iridium Flare that would become visible to me. This App, obviously by its name, also tracks the International Space Station and shows where and when to look for the ISS to become visible as it orbits above your location. The App uses data from the Heavens-Above web site, one of the best online resources for star maps, ISS and other satellite flyby events.
   What is an Iridium Flare? Iridium is the name for a series of around 60-70 numbered communication satellites orbiting the Earth. The ‘flare’ is simply the reflection of sunlight off the satellite’s solar panels. You see this reflection as a sudden burst of light, a flare, as the satellite re-positions its orientation to the Earth to keep its antenna aimed at ground-based antennas.
A 'Bonus' Satellite Flyby

A ‘Bonus’ Satellite Flyby

   Given the time, direction, and altitude for Iridium Satellite #3 and the Starry Night Pro program I was able to see what the satellite’s path would look like. For this particular satellite it would travel toward the southwest below the length of the summer triangle asterism from near the star Deneb toward the small constellation of Delphinus the Dolphin, as the labeled picture at the top of the page shows. Then it was simply a matter of setting up my trusty Canon Rebel T3i on a tripod and doing a series of test pictures trying to find the best settings.
   For the satellite flyby – which was totally unexpected – I was using 3.5 second time exposures at F4.0, with an ISO setting of 1600. These are also the settings I used for the flare sequence of pictures. Some of the pictures have additionally been enhanced using Photoshop and Image Enhancement/Auto Levels settings.

   Click here to read about and see additional pictures of the ISS and Iridium flares.

   To pause the slideshow move the cursor over the pictures to bring up the controls.

   Click here to go to the Qué tal in the Current Skies web site for more observing information for this month.

ISS This Morning

dolphin   Earlier this morning the ISS, International Space station, flew over the midwest in a path that lasted 4 minutes and at its peak the ISS reached 85 degrees in altitude – nearly straight up. The path it followed took it from the southwest horizon across the summer triangle past the star Altair in Aquila the Eagle, towards the east northeast horizon.
   I was hoping to catch the ISS as it flew past some interesting groups of stars like the two small constellations of Sagitta the Arrow and Delphinus the Dolphin however the sky was too bright at this early hour for those stars to show up against the brighter background.
   In this sequence of images the sky at 0530 CDT was fairly bright and there were some high cirrus clouds but the ISS was as bright as Venus appears and was very easy to follow with my camera. The images are 2 second time exposures with an aperture setting of f4, and the lens was backed out to 18mm for a wide field of view.

   Click here to go to the Qué tal in the Current Skies web site for more observing information.