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Transit of Venus Skywatch

At the

Nehru Planetarium

Nehru Memorial Museum and Library

Observations were conducted in collaboration with the Amateur Astronomers Association, Delhi, and a support from the Vigyan Prasar for the construction of the special dark room for projection

Day started by 3 AM getting ready to screen-capture webcasts from Hawaii and Mt. Wilson for views of the first and second contacts obtained there.

In the screen captures from the webcasts, we managed to save the third contact image from the NASA edge webcast from Mauna Kea, Hawaii...

Second Contact through screen capture from the NASA Edge webcast from Mauna Kea

... and use the unbelievable Solar Dynamic observatory image of the first contact ...

 ... as well as live webcasts to show the early morning viewers at the planetarium, while they waited for the Sun to rise and then for the clouds to clear.

However, webcasts were viewed only until sunrise time, following which, even though clouds played spoilsport until 7 AM, visitors remained near the telescopes and projection setups rather than view the webcasts, anxiously waiting for the clouds to clear.

7 AM onwards it was action time for all observing stations in the Teen Murti campus!

The first glimpses were through a DSLR camera equipped with solar filters with its mount polar aligned and thereafter tracking manually. Anurag Garg and Balachander of the planetarium worked on the rehearsals for this over a few weeks. The first few images after 7 AM on the transit day showed the Sun through the remaining thin clouds with some of the images showing Venus out of this cloudy art on the Sun ...

Image captured by Anurag and Balachander of the planetarium

And then, the old reliable sun gun prepared at the planetarium by Ramesh Chikara and used for so many eclipses in the past, was the next station to allow good views of Venus nestling on the disk of the Sun for everyone ...

A special attraction was a dark room which was constructed by Naresh Kumar and his team using wooden hardboard, and darkened further with curtains, which allowed a projection through a telescope to be viewed as a very large image on a screen placed inside. Preparing this, and using it successfully during the transit was very satisfying, as it allowed us to recreate methods used in the 17th century for observing transits and sunspots. This and the Sun gun station were setup with the appropriate telescopes, by Ramesh Chikara of the planetarium and used ably during the transit by him and amateur astronomers and volunteers - Vishnu Rettinam and Mayank Agarwal of AAAD, IP University students and many others.

The dark room had a large wall covering on the outside explaining the spirit in which we had attempted this excercise.

A host of long projection boxes with a refractor inserted into one end and viewing made possible on the other end, were prepared at the planetarium by technician Naresh Kumar, and set up as seven observing stations. The refractor, in fact, was a Galileoscope given to the planetarium during the International Year of Astronomy 2009 Galileoscope project as an exchange from the Museum of Innovation, San Jose. Students of Gargi college and I. P. University and many others used these stations for successful observations and some measurements.

The quality of projection with this setup was simply unbelievable! One can judge through this image taken during the third contact, using a cellphone by one of the students from Gargi college, the group which did a good number of measurements using these projection setups - Shayoni Panja, Namrata Gurung, Vishi Agarwal, Ayushi Vashishtha, Deepika Yadav and Adhishree Khaitan of Gargi college, Richa from Miranda House and two students from IP University.

The success of these projection boxes came from the wonderful accuracies which seemed obtainable in angular diameter measurements for the Sun and Venus. The results from groups of students who had practiced earlier measuring Sun's angular diameter, during the workshops which had been conducted in collaboration with the Vigyan Prasar, are awaited. Here is one result obtained by a pair of young professionals Ujjwal and Sugandha, who encountered this exercise for the first time, when they came in to view the transit. I saw the same thrill dawn on them about the kind of accuracies possible with such simple equipment and some careful observations, which we have seen with many students again and again, when they have used these projection boxes for observations of the Sun and sunspots.

A zero-cost equipment which was wonderfully effective, was the ball and mirror projection which was seen inside our sky theater in air conditioned comfort, by many. Visibility of Venus in this projection was quite good and discussions were held for the viewers by O. P. Gupta.

However many projection setups are there in a skywatch, and no matter what all ways we attempt to make them interestingly different each time, visitors are not satisfied until they have had eyepiece views of the event through a telescope. Equipped with safe solar filters covering the objective, of course. The most serpentine of queues will be seen near these telescopes. The entire load of showing visitors, views through these telescopes was taken by the members of the Amateur Astronomers Association, Delhi, as always. Chandan Bhatia and Rajiv Sharma were at the telescopes, non stop, from 7 AM to 10:22 AM and many other members of the association assisted with these and other stations.

All along, people were, of course, attempting to view Venus on the Sun, perhaps only just barely discernable, through the solar filter goggles.

Planetarium artist Rajesh Harsh obtained a number of images of the Sun visible through foliage and inspired by the phenomenon worked on some paintings right then and there.

And finally, this image without filter in front of the camera, risked by Balachander, while clouds were playing hide and seek. Using only the LCD screen and looking at camera shadow to see that it is pointing at the Sun.

All images have been uploaded on

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Page last modified on June 12, 2012, at 02:38 AM EST