Observing the
Transit of Venus across the Sun
from Luxor, Egypt.

By Kavan Ratnatunga, 2004 June 8th

To observe the rare Transit of Venus across the face of the Sun on 2004 June 8th I decided to travel to Egypt. Although the Full Transit could be seen from South Asia or Europe, middle east particularly in southern Egypt had the highest probability for clear sky. I had never visited Egypt or even any other country in Africa and this was a additional reason for the selection. Unlike for example a total eclipse of the Sun which happens some place on earth every year, no one currently living on Earth had seen a transit of Venus since the last occurrence was in 1882. I didn't want to miss any of it due to cloudy skies.

After much preparation I flew from Pittsburgh via Amsterdam into Cairo, arriving late in the night on June 2nd at 1:15AM. The next 5 days was a fabulous trip down the Nile seeing the many interesting Museums, Temples and Tombs. I visited the Cairo Museum, Pyramids of Giza, the Sphinx, The Philae Temple in Aswan, Abu Simbol, Kom-Ombo, Edfu, Luxor Karnak, etc. An great trip through 5000 years of incredible History.

On June 7th after touring the Valley of the Kings and the Valley Queens and other monuments in the West-Bank of the Nile I checked into the New Winter Palace hotel in Luxor. I was given a 5th floor room with a nice view of the Nile and the Luxor Temple. I decided it was time to select a place with a good view of the Eastern Horizon. There didn't seem to be one from the grounds of the Hotel, and the roof-top had a tall wall around it obstructing any view of the horizon. When I inquired at the reception, they said they could open a room on the garden-side of hotel if I wanted to see sun-rise. So I asked them to move me to such a room. They were glad to do that since rooms on that side had less demand.

I found that the local Arabic language Newspaper had an illustrated full page article on the Transit of Venus with interviews of Local Scientists. I was too late to find a copy of the English Newspaper which seems to have very limited circulation. Speaking with few persons I saw hardly any interest. I guessed they considered the astronomical event was something they could only watch on TV. One person in hotel reception even warned me against looking at it. So I guess the authorities had worked hard to encourage the public to watch Transit only on TV.

I was glad I didn't have to carry the 3.5 inch Questa telescope and other equipment early morning to setup and could observe relaxed from the balcony of my hotel room. That evening I went to watch the Sound and Light show in the Karnak Temple. After returning to the hotel room I set up the equipment at night and focused on the moon. Everything was in order. Sun Rise was around 6 AM and the Transit started at 8:20 AM.

I woke up before the wakeup call and got ready to photograph Sunrise before the transit of Venus. The sky close the horizon was foggy. Although there were no clouds in the sky, the cities in Egypt have a lot of pollution and combined with the dusty create a fog. The night sky from the cruise ship docked in Esna which is not a big city was no different to the sky from a major US city like Pittsburgh on a clear night. I could only see 2nd magnitude stars in the sky. The Sun on the horizon could be photographed without the solar filter. The exposure indicates that the extinction at sunrise was about the same as the 14 magnitudes of solar filter.

A foggy Sunrise in Luxor on June 8th

The Sun usually has a few sun-spots but none could be seen on that day. It was hard to orient to know exactly where Venus would enter the solar disk. I mounted the camera at the prime Focus behind the mirror of the telescope so that I could both Photograph the event as well as observe it visually through the eyepiece, needing only to change the focus. Within a minute of the expected start time I was able to see First contact and watched and took photographs of the event over the next 20 min till well past 2nd contact. The Black-drop effect was observed briefly after 2nd contact with the region between the outer edge of the rim of Venus and the rim of the sun being darkened like a shadow.

Transit of Venus
photographed from Prime Focus

Observing from Luxor hotel balcony

After the disk of Venus had moved well within the Sun face, I switched to observing through the eyepiece and Barlow which gave about 2.7 times the magnification. However at this focus it took more effort to keep Venus within the field of view which shows only part of the Sun-face. I mounted the camera at the eye piece mount of telescope and took more photographs with and without the Barlow. All of the exposures were done at one millisecond (0.001 second), the fastest speed of the TOPCON SLR camera I was using. This was slightly over-exposed for the Prime Focus or Eye Piece mount. It was maybe slightly under-exposed when using the Barlow but I decide that was to try see any detail which would get washed out in a longer exposure. All the exposures were taken with the 12 second delay timer on the camera to ensure any jitter from handling the camera had dampened by the time of exposure.

When the hotel house-maid came to make the room I showed her the view of the transit and the Arabic Newspaper so she knew what she was looking at. She went way intrigued and told her friends and soon I had two other hotel employees come to observe the transit.

Observing from Luxor hotel garden

Transit of Venus
photographed from Eyepiece mount with Barlow

As noon approached the Sun could no longer visible from the hotel room balcony. Rather than go to the hot rooftop I decided to go down to the garden of the hotel. The Sun could be observed and with many trees around it was less hot. One of the hotel employees I had shown the transit went and found me just the right bench to sit down even without asking for it. The camera could no longer be mounted at the prime Focus. I took photographs at regular intervals with and without the Barlow.

I soon realized I had not brought down an extra roll of film. I was reluctant to just leave the setup to get it. So when the next group of hotel guests came to find out what I was doing, I showed them the transit and asked them to stay and look at it while I went to get more film. Many had heard about the transit but none had planed or expected to see it. I know there were other groups in Luxor, but I didn't see any. The TV did show some astronomical groups observing the transit from Cairo, where it had not been too clear at the start of the Transit. Cairo was often overcast on many of the few days we were there.

Third contact was at 14:06 and end of Transit was at 14:26. The Black drop effect was not seen maybe because the Sun was at high altitude. I should have changed to a new roll well in advance of 3rd contact. So took fewer closer to 3rd contact. After putting in a new roll of film it took a few extra minutes to get the telescope pointed at the mid day Sun. I missed taking photographs soon after 3rd contact although I saw it while readjusting the telescope. I then decided to just take as many photographs as possible, as fast as I could manually wind the film and the timer.

I had found a KODAK Film developing Shop Luxor which had the equipment in the store. Many of the other places which accepted film for development probably sent it to them. Although labeled 1-hour photo, it did take a few hours to process. I decided the risk of damage to film through all the Airport X-ray machines was significant. I had given on the previous day a few rolls of travel photographs to print and develop. This allowed me to ensure the quality of film developing in this shop in Luxor was OK. Development and printing cost was also lot cheaper than in USA. The cost was US50 cents to develop the roll and US12 cents per 4x6 inch print. I gave the first 2 rolls to develop and went in the horse drawn carriage to look at the Luxor Museum. Picked up the developed Film and Prints on the way back to hotel.

I was glad that I had got nice photographs of the Transit of Venus across the Sun. After many years of talking about this transit, it was now over and time to catch the evening by train to return to Cairo. An unexpected encounter with a Bedouin in Saqqarah gave me a chance riding a Camel to see the Step pyramid, but that is another story.

Venus with a diameter (6370km) slightly smaller (about 95%) of that of Earth has a mean apparent diameter of 60 arc seconds at inferior conjunction. The relatively thin Atmosphere (75 km) is 0.6% of the diameter or 0.35 seconds of arc. This much less than blurring (typically 1 second of arc seeing) through the earth atmosphere. It will not be visible through a small telescope even in ideal conditions. The clearly visible halo around the planet seen in the perfectly focused photographs is probably caused by diffraction.

Please follow the links, particularly click on the word photographs to see a Javascript driven sequence of images taken near the start and end of the transit as Venus entered and left the face of the Sun.

In Pittsburgh where only the last hour of the six hour event was visible, it had been sufficiently clear for Xiaojin Zhu a graduate Student in LTI.CS.CMU had obtained some great images.
In Slovakia Tomas Muraska managed to image the International Space Station (ISS) crossing the Sun while Venus was also in transit.