the
Master Partnership Agreement (MPA) for the construction of the
$1.5-billion Thirty Metre Telescope (TMT), what would be the
world’s largest optical and infrared telescope, was signed by the
five partner countries — Canada, China, India, Japan and the U.S.
— in Hawaii, the site for the proposed telescope.
Besides
the Indian Institute of Astra , the other participating
institutions in the TMT-India Programme are the Inter-University
Centre for Astronomy and Astrophysics (IUCCA), Pune, and the
Aryabhatta Research Institute of Observational Sciences (ARIES),
Nainital. While the IUCAA functions under the UGC, the other two
are under the DST.
With
the signing of the MPA, India will be moving from its current
observer status to a full-fledged partner in the project and will
be a member of what is called the TMT Collaborative Board. This
Board will eventually be replaced by a Governing Board, which will
manage the TMT International Observatory on behalf of its partners
The
main promoters of this international project are Caltech and the
University of California in the U.S. and the Association of
Canadian Universities for Research in Astronomy (ACURA), with
China, India and Japan providing additional financial and technical
support in return for participation in its construction and
observation time.
India
is a 10 per cent partner in the project, which implies a financial
commitment of about Rs. 1,000 crore. Much of India’s contribution
will be in-kind. Indian institutes and the industry are
collaborating to build much of the telescope’s control systems,
whose estimated value is about Rs. 600 crore
At
present, India has three 2 m class optical-IR telescopes and a 3.6
m telescope waiting to be commissioned. The apertures of the
current ground-based large optical-IR telescopes are in the 8-10 m
range, though other bigger ones like the TMT are also on the anvil,
the 39 m European Extremely Large Telescope (E-ELT) in particular.
Though the Indian astronomical community has been using the
existing 8-10 m class telescopes, such usage has largely been
limited to individual efforts.
The
TMT, which belongs to what are called the “new technology”
telescopes, was proposed after the enormous success of the first
new technology telescope, the twin 10 m Keck telescope on Mauna
Kea. The TMT will also be a segmented mirror telescope with its
primary 30 m mirror made up of 492 hexagonal segments of 1.44 m
each. Precisely aligned, these segments will work as a single
reflective surface of 30 m diameter. The TMT has a collecting area
of 650 sq. m. and will have observational windows from UV to mid-IR
wavelengths (310 nanometres to 28 micrometres). Its large
collecting area makes it 81 times more sensitive (measure of the
faintest signal that it can detect) than the current largest
ground-based telescopes.
Like
all ground-based observatories, TMT is limited in spatial
resolution by the atmospheric turbulence. While the 30 m primary
mirror builds on the technological and operational experience of
the Keck Telescope, it will be the first ground-based telescope to
incorporate the technology of Adaptive Optics (AO) as an integral
component of the telescope. AO refers to systems designed to sense
atmospheric turbulence in real time, make the appropriate
corrections to the beam and enable true image on the ground limited
only by optical diffraction. The AO capability will enable the TMT
resolve objects by a factor of 3 better than the 10 m-class
telescopes and 12 times better than the Hubble Space Telescope
(HST).