The Venus Transit 2004

... Photos by Themes

The Parallax Effect

When exchanging their photos, observers of the Venus Transit who were located at different sites were able to demonstrate the "parallax effect". This simply means that - at any given time - their sighting lines are (slightly) different. Geographically separated observers thus see the dark disk of Venus at (slightly) different positions on the solar disk. The larger the distance between the observers, the larger and more obvious is the effect. Precise measurement of the angular distance between the (simultaneous) Venus images then offers the opportunity to determine the distance to the Sun.

An overview of the VT-2004 Photo Archive is available and some of these photos have been elected "VT 2004 Photo of the Day".

All photos on this page may be downloaded and used, provided the photographers (authors) and the VT-2004 programme are indicated as source.




Combined Photos




Venus Transit from Denmark and Australia [Animated GIF 343 x 238 pix - 51k] Astronomy Group - Sønderborg and Learmonth Solar Observatory [Comparison of Venus' path across the solar disc, as observed from Denmark and from Australia. The position shift is due to the difference of the line-of-sight. The path, as seen from Australia, is shifted slightly upwards relative to that seen from Denmark because of the more southern geographical position of Australia.] June 8, 2004 Sønderborg, Denmark Exmouth, NW Australia	Venus Transit from Austria and South Africa [2667 x 2000 pix - 304k] Verein Kuffner Sternwarte and Pretoria Center of the Astronomical Society of South Africa [Verein Kuffner-Sternwarte and Pretoria Center of the Astronomical Society of South Africa have combined their two Transit-Webcasts from Heldenplatz (Vienna, Austria) and Pretoria, (South Africa) to show the Venus parallax in 3D. Webcast-image-series were aligned so that the transit tracks are parallel. The individual images were shifted and scaled so that the images of the Sun overlap, and finally the parallax of Venus was aligned such that it is parallel to the eye's parallax. The result is a 3D-anaglyph to be viewed with red/cyan-goggles. N is appr. to the right, the left-right direction is parallel to the line Vienna-Pretoria.] July 8, 2004 Vienna, Austria and Pretoria, South Africa

Venus Transit from Denmark and South Africa (1) [Animated GIF 508 x 364 pix - 156k] Astronomy Group - Sønderborg and Pretoria Centre of the Astronomical Society of Southern Africa [Comparison of the parallax effect by means of (near-)simultaneous images observed from Denmark and from South Africa. Danish image was taken taken at 10:57:35 UT - South African at 10:57:27 UT] June 8, 2004 Sønderborg, Denmark, and Pretoria, South Africa More information here.	Venus Transit from Denmark and South Africa (2) [184 x 177 pix - 54k] Astronomy Group - Sønderborg and Pretoria Centre of the Astronomical Society of Southern Africa [Comparison of the parallax effect by means of (near-)simultaneous images observed from Denmark and from South Africa. Danish image (lower) was taken taken at 10:57:35 UT - South African image (upper) at 10:57:27 UT] June 8, 2004 Sønderborg, Denmark, and Pretoria, South Africa More information here.

GONG Composite from Three Sites [859 x 859 pix - 212k] GONG Collaboration From Udaipur (India), learmonth (Australia) and El Teide (Canary Islands, Spain) [Comparison of images from these three sites, showing the small shift in Venus' position on the solar disc, caused by the different geographical location of the observing sites - submitted by John Leibacher] More images at this site June 8, 2004




[VT-2004 Photo Archive Top Page]

last modified: 2004/12/29

The Venus Transit 2004

... Photos by Themes

The Parallax Effect

Combined Photos