Astrophotography by Anthony Ayiomamitis

Star Trail Image Gallery

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 capibility 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: The city of Eretria lies on the western coast of Euvoia, Greece's second largest island, and is characterized with a rich history which dates back to the Neolithic Period (3500-3000 BC). The first reference by Homer occurred in The Illiad when Eretria participated in the Trojan Wars. Eretria was completely destroyed by King Darius I in 490 BC when he led the Persian forces in their first attempted invasion of Greece and which culminated in his defeat at Marathon. The city was rebuilt during the next decade and participated in a later battle against the Persian forces but now led by Darius' son Xerxes I in 479 BC.


Image Details
Stargazer
Imaging Details
Proper Star Name:
Polaris

Bayer Letter:
Ursae Minoris

Tycho Catalog:
TYC 4628-237-1

SAO Catalog:
SAO 308

Luminosity
2290 +/- 282 x Sun

Distance:
431 +/- 26 light yrs

RA / Dec:
02h 53m 42s /
+89 19' 52"


B-V Color Index:
+0.570 mag

Magnitude:
1.98
Date:
July 31-Aug 1, 2017
22:20 - 04:44 UT+3


Location:
Eretria,
Euvoia, Greece


Equipment:
Canon EOS 6D
Baader BCF2 Filter
Canon EOS EF 28mm/f1.8 USM
    @ f8.0


Exposures:
384 min (743 x 30 sec) (RGB)
005 min (010 x 30 sec) (Dark)
ISO 800
JPG Fine Image Format
5472x3648 Image Size
Custom White Balance
Manual Mode
Continuous Servo Mode


Software:
Startrails V2.3
Photoshop CS5


Processing:
Dark Frame Reduction
Layers and Lighten
Resampling
Unsharp Masking
JPG Compression