As soon as you see these images, you’ll probably guess who the photographer is … yes, Thierry Legault. He had less than half a second to capture these incredible shots of the Shenzhou-10 module docked to Tiangong-1 Chinese station transiting across the Sun, and it he did it not only once, but twice, on two consecutive days. Can you see the tiny spacecraft among the sunspots? And keep in mind, there are three taikonauts in these images as well, as the Shenzou has been docked to the Chinese space station module since June 11!
The Tiangong-1 space station is just 10.4 meters (34.1 ft) in length, while the Shenzou 10 is 9.25 meters (30.35 ft) long. This top image is a crop of a full-face view of the Sun, (see the full-face view on Thierry’s website) taken with white light filters by Thierry from southern France on June 16, just after noon UTC. The transit duration was just 0.46 seconds, and Thierry calculated the distance of the spacecraft to observer was 365 km away, and the spacecraft was traveling at 7.4km/s (26,500 km/h or 16,500 mph).
He used a Takahashi TOA-150 refractor, Baader Herschel prism and Canon 6D (1/4000s, 100 ISO).
Below is another solar transit of the two Chinese spacecraft, also taken from Southern France, but the next day, June 17, 2013 at 12:34:24 UTC. This one, in Hydrogen-alpha shows the Shenzhou-10/Tiangong-1 complex in multiple shots over the 0.46 second transit.
Hydrogen-alpha solar transit of Shenzhou-10 module docked to Tiangong-1, taken from Southern France on June 17, 2013 at 12:34:24 UT. Credit and copyright: Thierry Legault.
For this image, Thierry used his Takahashi FSQ-106, Coronado SM90 double stack, camera IDS CMOSIS 4Mp sensor at 38 fps.
This isn’t the first time Thierry has trained his cameras on the Tiangong-1 – in May of 2012 he captured the tiny space station alone transiting the Sun, and it was dwarfed by a huge sunspot sported by the Sun at the time.
In a previous interview with Universe Today, Thierry explained how he prepares to take images like these:
For transits I have to calculate the place, and considering the width of the visibility path is usually between 5-10 kilometers, but I have to be close to the center of this path,” Legault explained, “because if I am at the edge, it is just like a solar eclipse where the transit is shorter and shorter. And the edge of visibility line of the transit lasts very short. So the precision of where I have to be is within one kilometer.”
Legault studies maps, 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!”
He uses CalSky to make his calculations and figure out the timing.
Congrats to Thierry and our thanks to him for sharing his amazing images and skills with Universe Today!
Diagram of Shenzhou-10 (right) docked with Tiangong-1 (left). Via Wikimedia Commons.
Source: Universe Today, story by Nancy Atkinson