STUDYING THE SUN OVER UDAIPUR

In Spring of1996 I was invited to attend the wedding of a friend and high school teacher who lives near Udaipur, India. The invitation caught me at a time when I was ready to take a break from Silicon Valley and visit someplace that was truly exotic.

I booked a flight to New Delhi. After landing in the middle of the night, I found a taxi driver who was willing to drive me to Udaipur. The ride through the night was a wild experience, but I arrived safely in Udaipur in time for the wedding. I discovered that Udaipur is an ancient city with a busy city center, a maharaja's palace on a hill, and forts on the highest hills. I was surprised to see observatory domes reflecting the hazy morning sun from the middle of the lake in Udaipur.

This winter Jan 2001 I returned to India with my brother Paul Copeland to attend the Mahakumbhamela held every 12 years in Allahabad. After the Mahakumbamela we went to Udaipur to visit my old friend Onkar to learn more about the Udaipur Observatory.

I assumed that the observatory was an amateur site or at best used by a local college for astronomy instruction. I contacted the head, Dr. Venkatakrishnan by telephone and found that the name of the observatory is the Udaipur Solar Observatory (USO). I was surprised to find that the USO is doing world class solar studies.

We obtained a car and driver from the Indian Tourist Office and drove to Udaipur. I experienced another wild ride dodging lorries, camel carts, elephants, holy cows, and the occasional gang of monkeys.

The first morning Paul and I walked along the lake to get a better view of the observatory. To our astonishment a flock of flamingoes flew in and took up feeding in the lake next to the island holding the observatory.

The next day we were warmly welcomed by Dr. Venkatakrishnan. He told us he was happy to show us around and answer any questions.

Photo by Paul Copeland welcome

Dr. Venkatakrishnan introduced us to his staff.

Photo by Paul Copeland staff

Back row, from left: Rakesh Jaroli, office clerk; B. Ravindra, research scholar; Shankar Lal Daliwal, helper; Brajesh Kumar, scientist; Ramchandra, carpenter; Raju Koshy, tradesman.

Middle row seated from left: Sanjay Gosain, scientist; P. Venkatakrishnan, professor and head of USO; Arvind Bhatnagar, emeritus scientist, founder and former head of USO; Ashok Ambastka, Associate professor; Sudhir K. Gupta, technical assistant.

Bottom row from left: TBD.

On the Island

Dr. Venkatakrishnan lead us on a short hike to the edge of the lake. On the island opposite to where we were standing a small rowboat was waiting with one of his staff, who rowed rowed us across. We climbed up some stairs and saw the domes of the observatory in a different light. What a peaceful, cool island.

Photo by Paul Copeland island

As we climbed up the stairs, Dr. Vendatakrishnan told us we are part of a behavoiral experiment, but he couldn't tell us the nature of the experiment until it was time to go. His eyes twinkled mysteriously, but then he went on to the next subject -- the USO instruments.

Instruments - USO Telescopes

Full Disk Telescope

A 6-foot Razdow telescope, with a 15-cm aperture lens, takes full disk H-alpha synoptic observations of solar activity. CCD cameras, monitors and a digital image acquistion and processing system provide real time monitoring.

High Resolution Spar telescope

A 12-foot solar spar with 25-cm aperture telescope is being used for observing small high resolution chromospheric structures with the help of a narrow passband Halle-birefringent filtered contered at 6563A H-alpha spectral line. The light beam can be diverted to other instruments for simultaneous study of different aspects of solar event.

Coudé Telescope

A 15-cm Zeiss Coude telescope is being operated for spectral study of solar prominences, flares, and active regions, and for testing optics and filters. The advantage of this telescope is that it can track the sun and feed the solar beam to heavy back end equipment placed on a stationary platform.

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Photo by Paul Copeland coudePD1

Photo by Paul Copeland coudePD

Dr. Venkatakrishnan and assistant watch the whole sun's disk as captured by the Coudé telescope on a high-resolution monitor.

GONG Telescope

A milestone was added to USO's history in October 1995, when it appeared on the world map as an important link in an international project, GONG - Global Oscillations Network Group. The USO is one of six sites around the world. USO was selected owing to its excellent observing and sky conditions.

The other five sites selected under GONG are located at the Canary islands (Spain), CTIO (Chile), Big Bear (USA), Hawaii (USA), and Learmonth (Australia), for a near continuous 24 hour solar coverage with the aim of probing the solar interior. The sophisticated, 1.5 million dollar, state-of-the-art instrument monitors the Sun automatically, and takes digital velocity images of the sun every minute. The USO data is then combined with the data obtained from other five sites at the central facility located at National Solar Observatory, Tucson, USA. The GONG project promises to unravel several fundamental problems of solar interior and general astrophysics.

The GONG instrument is not located on the island, but up a hill half a kilometer from the USO headquarters building.

The GONG instrument is based on a Michelson interferometer called a Fourier Tachometer and is supported by the National Science Foundation through the National Solar Observatory which is operated under a cooperative agreement between the Association of Universities for Research in Astronomy and the NSF.

Sudhir Gupta the responsible for maintaining the instrument. He took us there and showed us the instrument.

Sudhir points out the mirror that follows the sun's position and reflects its image into fixed telescope tube.

The instrument sends data automatically to its home base via a satellite dish. Below, Sudhir sits at his workstation where he monitors the status of GONG, changes the data tapes, and backs up all data.

History of the USO

Professor Arvind Bhatnagar (now Emeritus Scientist) built this facility starting in 1975. Before that he was supervisor of the Big Bear Solar Observatory in the San Bernadino Mountains of California, USA (http://www.bbso.njit.edu/). He went there on a Carnegie Fellowship. Two scientists visited him from India in 1971 and asked why there was no such facility in India.

Dr. Bhatnagar agreed and wrote a proposal to PRL to build a "Big Bear east." He argued as follows:

The proposal was funded and by 1975 a modest solar observatory was started. The instruments were donated by friends, notably Dr. Ron Giovenelli, an Australian solar astronomer. The first observations were made in 1976.

Solar Studies at the USO

Dr Venkatakrishnan explained that they put the observatory in the middle of the lake to cut down on heat radiating through the atmosphere. The water absorbs most of the sun's energy and reradiates very little.

"However," he went on, "we do experrence some radiative distortion and we can compensate for much of the distortion with our image processing software. A more complete solution to overcome the distortion would be to build a Multi Aperture Solar Telescope (MAST). We currently have a proposal in to our parent laboratory, the Indian Government Physical Research Laboratory."

Examples of Studies

[Taken from lecture materials provided by professor Ashok Ambastha, USO.]

Solar Disk Study

High Resolution Sunspot Study

Mass Ejection

The following image shows an example of Mass Ejection study from February 1999.

Study of Magnetic Properties of Plasma Loop

The following image shows part of a sequence recorded of the rise and escape of a loop prominence.

X-ray Detection Study Over the Period of a Day

Departure

As we left the observatory the sun was setting. I caught a glimpse of the red sun sitting like an incandescent egg in a palm tree next to the dome. It seemed like we had only been there a few minutes, and yet the whole day had passed away. I remarked about this to Dr. Venkatakrishnan. He broke out in a big smile and thanked us for providing more data for his behavioral experiment.