A 2.1/2 hour star trail image taken looking towards a southerly direction, from Western Australia. See Star-trail stacking for description of the software used to create this image.

Star trails


The photo below was taken in an attempt to determine an approximate direction of South from the balcony of my south facing apartment in Bangkok. The photo is a stack 53 separate photos taken at 1 minute intervals of the the star Achernar as it crosses the meridian. Due south is determined as the point which it reaches the highest altitude angle. Since I come from Australia, I am used to Achernar rotating in a circle much higher in the sky.