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 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: Although pyramids are widely associated with Egypt, there exist sixteen examples of pyramids across Greece! Perhaps the most well preserved example of a greek pyramid is that at Hellinikon which is situated approximately 155 km southwest of Athens and less than 10 km from legendary Argos. Using optical thermoluminescence dating of sample material taken from the pyramid, a 1995 study determined the Pyramid at Hellinikon to have been constructed around 2720 BC (+ 580 years) and which would preceed the famous Pyramid at Ghiza by a full century. This date is generally rejected with the general concensus being that it was probably built some time between the 6th and 4th centuries BC and which is supported, for example, by clay pottery remnants from the neoclassical age of Greece recovered during excavations. The two longer sides of the pyramid measure 12.58 and 14.70 meters, respectively, whereas the two shorter sides are 8.62 and 8.61 meters respectively. The pyramid is inclined at an angle of 60 degrees and rises to 3.5 meters in height. Although various uses have been cited including for astronomy, the most probable scenario based on the writings of the 2nd century AD geographer Pausanias suggests a mass burial site for fallen warriors.


Image Details
Star Trails over the Pyramid at Hellinikon
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 39m 31s /
+89 17' 39"


B-V Color Index:
+0.570 mag

Magnitude:
1.98
Date:
July 05-06, 2014
22:15 - 03:05 UT+3


Location:
Hellinikon,
Argolida, Greece


Equipment:
Canon EOS 350D
Canon EOS EF-S 18-55 mm
    @ 18 mm / f5.6


Exposure(s):
284 min (284 x 60 sec) (RGB)
006 min (006 x 60 sec) (Dark)
ISO 400
JPG Fine Image Format
3456x2304 Image Size
Continuous Servo Mode


Software:
Startrails V1.1
Photoshop CS5


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