One of the most basic types of astrophotography and yet equally stunning is that involving star trails, particularly
around the celestial poles or immediately due east or west. In addition to capturing the motion of stars around the
north pole which are circumpolar and, hence, never rise or set, we also have the ability to capture seasonal
constellations and stars in such photos, thus allowing for different opportunities during different seasons. Star trail
photos also provide direct evidence that our planet rotates and does so at a rate of 15° per hour. Furthermore, by
studying the arc for a particular star, especially as far away from the pole as possible, one can indirectly estimate
the length of the (total) exposure which often ranges from seven to eight hours in duration and is totally dependent
on the end of astronomical twilight one evening and its onset
the following morning.
Many star photos are centered on Polaris, a double star system which represents our quickest means to locating the north celestial pole, for it lies less than 1.0° from it, and is an excellent starting point for the polar alignment of a telescope (and finding your way home if you are lost!). Due to the extended length of the typical exposures involved, the best film for such work is Kodak Elite Chrome (ISO 100) whose reciprocity failure is nearly zero or Fujichrome Velvia and Provia (ISO 50 and 100) emulsions with equally impressive curves! With respect to equipment, it is rudimentary, for a camera with extended exposure capability is required along with a firm tripod and shutter release and locking cable. It is also preferable that the camera used have a mechanical shutter so that battery consumption and power does not become an issue during mid-exposure. The final requirement is a location with dark skies - the darker the better so that the trails and their colouration will be as bright and contrasty as possible - with, preferably, an interesting foreground which can be used to enrich the final result.
Note: One of the most stunning and well-recognized monuments associated with the Golden Age of Ancient Greece is the Erechtheion atop the Acropolis and which was constructed between 421 and 406 BC. Measuring over 8.0 meters in height, 20.0 meters in length and 11.2 meters in width, its southern compartment is comprised of six maidens (known as karyatides) whose head and torso not only grace the sides of the rectangular marble structure but whose heads also support its roof. The marble maidens are approximately 2.36 meters in height, dressed in ancient chiton (ionic style) which extends down to their ankles and with richly interwoven hair reaching their back. Karyatides are literally the virgin maidens from the small town of Karyes approximately two hours southwest of Athens and who were best known for their dances during annual celebrations in honour of the Goddess Artemis. Nearly 2500 years later, the residents of Karyes decided to reconstruct a faithful replica of the Erechtheion (in 1983) for display in their town as a reminder of the historical connection between the Erechtheion in Athens and their maidens from well over two millenia ago.
Note: For an excellent article on widefield landscape astrophotography including star trail work, see Astronomy Magazine (May/2017: 52-57).
Proper Star Name:
á Ursae Minoris
2290 +/- 282 x Sun
431 +/- 26 light yrs
RA / Dec:
02h 39m 31s /
+89° 17' 39"
B-V Color Index:
July 04-05, 2019
22:47 - 04:47 UT+3
Canon EOS 700D
Canon EOS EF-S 18-55 mm
@ 18 mm / f8.0
360 min (690 x 30 sec) (RGB)
005 min (010 x 30 sec) (Dark)
JPG Fine Image Format
5184x3456 Image Size
Auto White Balance
Continuous Servo Mode
Dark Frame Reduction
Layers and Lighten