Star Trail Splendour at Timau National Observatory: Visual Proof of Earth's Rotation
Senior Expert Researcher in Astronomy and Astrophysics at the National Research and Innovation Agency (BRIN), Thomas Djamaluddin, has successfully captured the mesmerising phenomenon of star trails in the skies of East Nusa Tenggara. The photograph was taken against the magnificent backdrop of the Timau National Observatory dome during the period of 18–19 June 2026.
Using a DSLR camera, Thomas conducted the image capture process over a total of 10 hours. Although the camera’s effective recording duration lasted only about 3 hours, the final result successfully displays an artistic pattern of concentric star circles in the southern sky, creating harmony between observation technology and the beauty of the universe.
Thomas explained that the primary purpose of this shoot was not merely photographic aesthetics, but rather as a means of public education regarding the phenomenon of Earth’s rotation. Many people are unaware that the apparent circular movement of celestial bodies is actually a consequence of our own planet’s spin.
“The rising and setting of the Sun, Moon, and stars are actually caused by the Earth’s rotation once every 24 hours,” said Thomas.
He added that because the Timau Observatory is located in the southern hemisphere, the star trails appear to specifically encircle the southern celestial pole.
Beyond natural factors, Thomas also highlighted a modern challenge in astrophotography, namely the density of satellites in Earth’s orbit, such as the Starlink constellation. To preserve the purity of the photo from interference by satellite light trails, he strategically began shooting when the night was truly dark and ended it just before dawn broke.
For members of the public or photography enthusiasts who wish to try capturing a similar phenomenon, Thomas Djamaluddin shared several technical tips that can be practised independently.
Through this visual work, BRIN hopes the public can better understand that the dynamic night sky is tangible proof that the Earth continues to spin ceaselessly on its axis.