India to build world's largest solar telescope

DELHI -- India's new telescope will beat out the McMath-Pierce Solar Telescope in Arizona.

DELHI -- Stargazers in India are hoping to study the sun more closely than has ever been done before.

The Indian Institute of Astrophysics (IIA), the country’s premier astronomical institute, has submitted a proposal to the Indian government for setting up a solar telescope along the Indo-China border. The telescope will be set up by 2017 near Pangong, a saltwater lake in Ladakh.

It will be the largest solar telescope in the world, according to the scientists at the IIA, who have called the project for its construction the National Large Solar Telescope (NLST).

The IIA scientists hope that the construction work for this telescope will begin by the end of this year. “Once the construction of the observatory is complete, it will house a telescope with an aperture of two meters,” said Dipankar Banerjee, a professor at the IIA and a core member of the NLST project.

Aperture refers to the size of the lens at the front end of the telescope. Presently, the largest telescope in India has a lens size of 60 centimeters (24 inches). Telescopes with larger apertures capture more light, and  allow more magnification.

The NLST will have the capability to discern objects and particles like sunspots spread 50 kilometers (31 miles) across the sun’s surface. Banerjee explained that existing solar telescopes only distinctly identify two objects on the sun’s surface if the distance of their separation is 70 kilometers (43 miles) and beyond.

The telescope will primarily be used during the day, but it can also be used for nighttime observation of other astronomical objects and events. The world's largest solar telescope is the McMath-Pierce Solar Telescope, which is housed in the Kitt Peak National Observatory at Arizona in the United States. The aperture of this telescope is 1.6 meters.

Banerjee explained that the sun, being the closest star to earth, is also the easiest to study. Observing the sun allows astrophysicists to understand processes in other stars.

The NLST will be built at a cost of Rs. 150 crore ($30 million).

Banerjee said that the area around the Pangong Lake offers clear skies with about 228 observational days a year, which makes it an ideal location to set up an observatory.

Dibyendu Nandi, an astrophysicist at the Indian Institute of Science, Education and Research in Kolkata, further explained that the high resolution of the telescope will give better clarity of the sun’s magnetic field. Magnetic energy stored in the sun’s atmosphere is released periodically, which leads to solar storms that contain the energy of one trillion hydrogen bombs.

Nandi explained that radiations and electromagnetic frequencies emitted during solar flaring can disrupt functioning of satellites, telecommunication networks, and scientific instruments based on earth’s magnetic field. Scientists expect that 2013 will witness a major solar storm that could knock off satellite navigation and communication. It could also impact the functioning of mobile phones.

Rajaram Nityanand, professor at National Centre for Radio Astrophysics in Pune, also noted that the new telescope would help to infuse young energy in the Indian pool of astrophysicists. “Telescopes stimulate a lot of activity because students come to do their PHD research,” said Nityanand.

“A PHD in astronomy makes a student very strong in software and physical modeling and many people in astronomy do move in to other fields,” he added.

The Indian telescope, however, will only be able to hold the world record until 2020, after which telescopes with apertures larger than four meters will become operational. China, for instance, is also planning to setup a solar telescope with a lens diameter between 5 to 8 meters.

Photo: Visible in the lower left corner, the sun emitted an M6 solar flare on Nov. 12, 2012, which peaked at 9:04 pm EST. This image is a blend of two images captured by NASA's Solar Dynamics Observatory (SDO), one showing the sun in the 304 Angstrom wavelength and one in the 193 Angstrom wavelength. Credit: NASA/SDO

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