Astrophotography by Anthony Ayiomamitis

Solar Image Gallery - Scenic Phenomenon

A common misconception is that the sun is larger when it is near the horizon than when it is high overhead. However, this optical illusion is not true, for the apparent size of the sun is virtually the same when it is rising or setting near the horizon or when viewed overhead (in fact, it is very slightly smaller when viewed near the horizon due to refraction as well as the greater added distance in observing across the earth's radius). This illusion has been wrongly attributed to landmarks near the horizon, such as homes and trees, supposedly giving a sense of perspective and whereas the same perspective is lost when looking at the overhead sun bathed in an empty sky. As noted by Donald E. Simanek and Carl J. Wenning, the real reason behind this trick by our brain is the perception of the sun (or moon) being against a "close" or "distant" foreground and which is lucidly described by the above two references.

However, if we were approach the apparent size of the sun methodically by studying it during perihelion and aphelion, we can detect a small change using photographic equipment thanks to the elliptical orbit of our planet around the sun which leads to variations in distance (and apparent size) of the order of about 3.4%. More specifically, at perihelion each January, earth is approximately 147 million km away from sun whose apparent diameter is about 32.53' whereas, at aphelion each July, earth is approximately 152 million km away and the sun is characterized with an apparent diameter of about 31.46'. This difference of 5 million km between perihelion and aphelion leads to the slight change in the apparent diameter of the sun as illustrated by two images of the sun captured six months apart when the sun was near its minimum possible perihelion (Jan 2/2005) and maximum possible aphelion (Jul 5/2005) and while crossing the local meridian and which are presented here.

Note: With summer solstice roughly two months away, the opportunity was used to pursue the setting sun a few kilometers from the seaside resort area of Oropos northeast of Athens and whose history dates to the time of the golden age of ancient Greece. The foreground is a distant summer home which lies atop a hill at an altitude of approximately 37 meters (120 feet). The photo was taken from a distance of 640 meters away to the east of the summer home so as to yield a reasonable balance in the aspect ratio involving the home and the setting sun as well as to provide the ideal azimuth and altitude for this photo to be possible.

A dramatic setting sun against the Church of Agios Sotirios was captured a few months earlier from a distance of 2505 meters away in the same general vicinity (see here, here and here).

Note: For additional photos of the sun and/or full moon against other well-known Greek archaeological grounds and sites, please click here.


Image Details
Colourful Spring Sunset
Imaging Details
Body:
Sun

Mass:
332,900 x Earth

Mean Eq Diameter:
109.1 x Earth

R.A / Dec:
01h 20m 11s /
08 27' 06"


Distance:
150 million km

Diameter:
31.92 '

Magnitude:
-26.8
Date:
Apr 11, 2010
19:46:38 UT+3


Location:
Oropos, Greece

Equipment:
Takahashi FSQ-106/f5
TeleVue 2x Big Barlow
Canon EOS 5D Mk I
Baader UV/IR-Cut Filter


Exposure:
1 x 1/80 sec
ISO 100
RAW Image Format
4368x2912 Image Size
Manual Mode


Software:
Digital Photo Pro V1.6.1.0
Photoshop CS2


Processing:
RAW to TIFF (16-bit) conv
Resampling (19%)
JPG Compression