Christoph Rollwagen - artics.de/cr

Christoph Rollwagen

Blog

  • June 6th, 2012
    🇩🇪 - 2012 Transit of Venus on island Usedom  (more…)

    On June 6th, 2012, the second and last transit of Venus of the current century took place. In Germany, only the second half of the event could be observed after sunrise.

    Together with some amateur astronomers I met on the evening before on island Usedom, because the weather forecasts made the best predictions for regions along the Baltic Sea. At least slight cloud cover was predicted for the rest of Germany. Since a transit of Venus is a twice-in-a-century event, we took the trip of about 200km, of course.

    Before sunset, we explored a beach near Karlshagen and chose it to be our observation site on the next morning. We spent the night in our cars parked behind the dune. About an hour before sunrise, we set up our equipment. For photographic capture I used a 1000mm MC MTO-11CA Maksutov f/10 mirror telephoto lens on a Canon EOS 50D DSLR mounted on top of an Astro5 telescopic mount with automatic tracking. For visual observation, I also mounted a 432mm William Optics Megrez 72FD Apochromat f/6.

    Above the southwestern horizon, the not-yet-set almost full moon illuminated the mild summer's night. I used the opportunity to focus my two telescopes so that the rising sun would be perfectly focused from the beginning. At dawn, a beautiful new summer day announced itself on the horizon line of the Baltic Sea. Only a few thin veils decorated the otherwise completely clear sky. There was no wind, the water was very calm. A few gentle waves rolled over the Baltic Sea. At sunrise at half past 5 the view along the horizon was almost free of clouds.

    I took my photos automatically at intervals using the software Canon EOS Utility. Additionally, I was able to trigger an exposure spontaneously via a cable remote control when needed. I adjusted the exposure times permanently, as the brightness of the solar disk progressively increased during the rising process. In addition, in the beginning I took photos without, later with a sun filter in front of the camera's lens.

    All observers on the beach looked through their cameras or telescopes and waited for the moment when the silhouette of Venus would become visible in front of the sun. At the right moment, I managed to photograph a clear 'Green Flash', which we all watched at the same time. A moment later, a round black spot came off the edge of the clouds. Air turbulences initially distorted the sharp view of the circular silhouette, but quite soon it became clear that this unusual-looking black dot was indeed the planet Venus, which glides in front of the sun. The last time I could enjoy this view happened 8 years before. And I knew that after this day, there would be no such opportunity in my life any more, because the next Venus transit will take place in the year 2117.

    :The sun was now climbing steadily through the haze over the horizon and around us a summer's day was beginning. A couple of beach walkers approached us to find out what we were doing in the early morning and they took their chance to take a glimpse through our telescopes.

    At half past seven, Venus had moved to the edge of the solar disk and crossed it within about half an hour. Unfortunately, nobody in our group was able to see the atmosphere of the planet at that moment. Possibly the visibility of the effect was prevented by thin veils that glided through the field of view towards the sun. Maybe also the air turbulence was too strong on that day. Also I could not recognize a drop effect during the exiting inner contanct of this transit. After the silhouette of Venus had left the solar disk, the transit was over.

    Date: June 6th, 2012 @ 02:40:16 CET
    Copyright: © Christoph Rollwagen
    Exposure: 1/3200 sec on ISO100
    Camera: Canon EOS 50D
    Lens: 1000mm MC MTO-11CA Maksutov f/10
    Location: Trassenheide, Usedom

  • February 2nd, 2012
    🔭 - The Sky in Motion  (more…)

    'The Sky in Motion' is a collection of diverse impressions of the night sky that I have taken in recent years, put together into a 30 minutes animation, made of 7 chapters.

    (I) Intro
    (II) Comets
    (III) DeepSky, Moon & Clouds
    (IV) Satellites
    (V) Solar Eclipses
    (VI) Lunar Eclipses
    (VII) Planets & Atmosphere

  • June 15th, 2011
    🇹🇷 - Total Lunar Eclipse in Turkey  (more…)

    The video shows an animation of the umbral phase of the Total Lunar Eclipse of June 15th, 2011. I took the single frames on the balkony of a hotel room in the Turkish coastal city of Antalya with a 1000mm mirror telephoto lens and a Canon EOS 50D DSLR, which was attached onto an Astro5 mount with automatic guiding. During the central stages of the eclipse, the moon became unusually dark and was barely visible to the naked eye.

    Date: June 15th, 2011
    Author: © Christoph Rollwagen
    Exposure: 8 sec on ISO100-1600
    Camera: Canon EOS 50D
    Lens: 1000mm MC MTO-11CA Maksutov f/10
    Location: Antalya, Turkey

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