Tiangong Space Station Sighting

Tiangong space station, or “Heavenly Palace”, is China’s new permanent space station. The country has previously launched two temporary trial space stations, named as Tiangong-1 and Tiangong-2. The new T-shaped Space Station is composed of three modules, Tianhe – which contains living quarters for crew members, Wentian provides additional avionics, propulsion, and life support systems and fitted with an independent airlock, while the Mengtian module is divided into multiple sections equipped with expanded in-orbit experiment capacity for microgravity experiments. The rare possibility of it being visible from Ireland was mentioned during a recent talk entitled “China in Space” at the Mayo Dark Sky Festival by Irish space writer and broadcaster; Brian Harvey who has authored several books about China’s space program as well as the space programs of India and Japan.

Unfortunately compared to the International Space Station that has an orbital inclination of 51.64°, Tiangong orbits much further south at an inclination of just 42.73°. So, in theory from our point of view its only visible for about 2 days a month at an altitude of 8° on its highest northerly pass over Spain, this happened on December 5th 2022. Using heavens-above.com the data I was using was for a pass from Galway City, my location of Ballina (54.1237° N -9.1441° W) did not show up at all even though it is only 1 degree in difference between the two. The data on the website said it was going to be magnitude +0.8 and I expected to view it about 4° south of Saturn which would be of similar brightness. But in the end, it was 3rd if not 4th magnitude and completely invisible to the naked eye.

I have been waiting for a chance to capture it for an exceptionally long time but the horizon hugging cloud always prevented me. On this date the Moon being 12 days old and 95% illuminated did not help, neither did the thoughts of trying to capture it the following evening when it was going to be visible an hour earlier but during nautical twilight with the Sun just -8.8° below the horizon. My aim was to catch it as it rose above the horizon but did not think that it would be invisible to the naked eye, my 8×50 binoculars would have been useful, so I was imaging blind. So, from 1839 -1841 using a Canon 6D I took 12 x 8 second exposures, with an aperture of F2 at ISO200. It appears as a faint white line, left of centre, while at the time it was about 1400km away and at an altitude of 390km. The far-off bright Star in a 2 o’clock position is Saturn while the bright star to the lower right at an 8 o’clock position is Fomalhaut, this is the brightest star in the southern constellation of Pisces Austrinus, the “Southern Fish” and the 18th-brightest star in the night. According to Brian Harvey it was the first sighting he knew of in Ireland or the UK.
In future I suggest using https://astroviewer.net for Tiangong predictions.

Thanks

Ronan Newman