Astrophotographer extraordinaire Thierry Legault has made a name for himself with his images of spacecraft transiting across the face of the Sun. He has done it again by capturing the first-ever image of the Tiangong-1 space station transiting the Sun. The monster sunspot, AR 1476 absolutely dwarfs the Chinese space station (inside the circle), but you can see incredible details of the Tiangong-1 below in a zoomed-in version. Legault had less than a second to capture the event, with the Tiangong traveling at 7.4km/s (26500 km/h or 16500 mph,) the transit duration was only 0.9 seconds! The size of the station is pretty small — as without solar panels the first module of the Tiangong measures just 10.3 x 3.3 meters.
Legault’s equipment was a Takahashi FSQ-106 refractor, a Baader Herschel prism and Canon 5D Mark II camera. Exposure of 1/8000s at 100 ISO.
As Legault told us in an interview earlier this year, in order to capture such images he studies maps, uses CalSky software, and has a radio synchronized watch to know very accurately when the transit event will happen.
“My camera has a continuous shuttering for 4 seconds, so I begin the sequence 2 seconds before the calculated time,” he said. “I don’t look through the camera – I never see the space station when it appears, I am just looking at my watch!”
For a transit event, he gets a total of 16 images – 4 images every second, and only after he enlarges the images will he know if he succeeded or not.
“There is a kind of feeling that is short and intense — an adrenaline rush!” Legault said. “I suppose it is much like participating in a sport, but the feeling is addictive.”
Thanks to Thierry for sharing his latest success, and you can see larger versions of these images, and much more at his website.
Nancy Atkinson is currently Universe Today’s Contributing Editor. Previously she served as UT’s Senior Editor and lead writer, and has worked with Astronomy Cast and 365 Days of Astronomy. Nancy is the author of the new book “Incredible Stories from Space: A Behind-the-Scenes Look at the Missions Changing Our View of the Cosmos.” She is also a NASA/JPL Solar System Ambassador.