Indian Astronomical Observatory.docx

Indian Astronomical Observatory From Wikipedia, the free encyclopedia

Indian Astronomical Observatory

Indian Astronomical Observatory, Hanle

Alternative names Hanle Observatory

Organization

Indian Institute of Astrophysics

Location

Hanle, India

Coordinates

32°46′46″N78°57′51″ECoordinates: 32°46′46″N 78°57′51″E

Altitude

4,500 m (14,800 ft)

Established

2001

Website

www.iiap.res.in/centers/iao

Telescopes

High Altitude Gamma Ray Telescope Himalayan Chandra Telescope Major Atmospheric Cerenkov Experiment Telescope

Location of Indian Astronomical Observatory Related media on Wikimedia Commons [edit on Wikidata]

The Indian Astronomical Observatory (IAO), is located near Leh in Ladakh, India, has one of the world's highest sites for optical, infrared and gamma-ray telescopes. It is operated by the Indian Institute of Astrophysics, Bangalore. It is currently the third (see List of highest astronomical observatories) highest optical telescope in the world, situated at an elevation of 4,500 meters (14,764 ft). Contents [hide]    

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1Location 2History 3Observation 4Facilities o 4.1Himalayan Chandra Telescope o 4.2High Altitude Gamma Ray Telescope o 4.3Center for Research and Education in Science and Technology 5Upcoming facilities 6See also 7References 8External links

Location[edit] The Indian Astronomical Observatory stands on Mt. Saraswati, Digpa-ratsa Ri, Hanle in southeastern Ladakh in the eastern Jammu and Kashmir state of India.[1] Accessing the observatory, located near the Chinese border, requires a ten-hour drive from Leh, the district capital of Ladakh.[2]

History[edit] In the late 1980s a committee chaired by Prof. B. V. Sreekantan recommended that a national large optical telescope be taken up as a priority project. The search for the site of the observatory was taken up in 1992 under the leadership of Prof. Arvind Bhatnagar. The scientists from the Indian Institute of Astrophysics found the site at Hanle.[3] The first light was seen by the Observatory 2-metre telescope on the midnight hour between 26 September and 27 September 2000.[1] The satellite link between the Centre for Research and Education in Science and Technology (CREST), Bangalore and Hanle was inaugurated by the then Jammu and Kashmir Chief Minister Dr. Farooq Abdullah on 2 June 2001. The Observatory was dedicated to the nation on 29 August 2001.[4]

Observation[edit] The Hanle site is deemed to be excellent for visible, infrared and submillimeter observations throughout the year.[2] Specifically the observation conditions yield about 255 spectroscopic nights per year, approximately 190 photometric nights per year and an annual rain plus snow precipitation of less than 10 cm. In addition, there are low ambient temperatures, low humidity, low concentration of atmospheric aerosols, low atmospheric water vapour, dark nights and low pollution.[1]

Facilities[edit] The Observatory has two active telescopes. These are the 2.01 meter optical-infrared Himalayan Chandra Telescope (HCT) and a High Altitude Gamma Ray Telescope (HAGAR). The HCT is

remotely operated from Bangalore from the Centre for Research and Education in Science and Technology (CREST) using a dedicated satellite link.

Himalayan Chandra Telescope[edit] The Himalayan Chandra Telescope is a 2.01 meters (6.5 feet) diameter optical-infrared telescope named after India-born Nobel laureate Subrahmanyam Chandrasekhar.[2] It contains a modified Ritchey-Chretien system with a primary mirror made of ULE ceramic which is designed to withstand low temperatures it experiences.[5] The telescope was manufactured by Electo-Optical System Technologies Inc. at Tucson, Arizona, USA. The telescope is mounted with 3 science instruments called Himalaya Faint Object Spectrograph (HFOSC), the near-IR imager and the optical CCD imager.[2][6] The telescope is remotely operated via an INSAT-3B satellite link which allows operation even in sub-zero temperatures in winter.[5] Milky Way over Himalayan Chandra Telescope, Hanle by Navaneeth Unnikrishnan

High Energy Gamma Ray Telescope (HAGAR), Hanle

High Altitude Gamma Ray Telescope[edit] The High Altitude Gamma Ray Telescope (HAGAR) is an atmospheric Cerenkov experiment with 7 telescopes setup in 2008.[7] Each telescope has 7 mirrors with a total area of 4.4 square meters. The telescopes are deployed on the periphery of a circle of radius 50 meters with one telescope at the center. Each telescope has alt-azimuth mounting.[8]

Center for Research and Education in Science and Technology[edit] The Center for Research and Education in Science and Technology (CREST) is situated 35 km to the northeast of Bangalore near Hoskote town. The Center houses the control room for the remote operations of the 2m Himalayan Chandra Telescope (HCT) at the Indian Astronomical Observatory, Hanle, and the HCT data archive. The operations are controlled using a remote satellite link.[9]

Upcoming facilities[edit] The Indian Institute of Astrophysics is collaborating with the McDonnell Center for the Space Sciences of Washington University in St. Louis, US to operate two 0.5 meters Cassegrain telescopes to monitor active galactic nuclei. One of the observatories is to be established in Hanle.[2] The facilities 180 degrees apart in longitude are together to be called the Antipodal Transient Observatory (ATO).[10] A Himalayan Gamma Ray Observatory (HiGRO) is being set up at Hanle in collaboration with Tata Institute of Fundamental Research, Mumbai and Bhabha Atomic Research Centre, Mumbai. This is currently in the advanced stage of commissioning and is expected to be functional by 2018. Major Atmospheric Cerenkov Experiment Telescope (MACE) was expected to be set up here by December 2012.[11] The Experiment expects to have a 21-meter collector which can collect gamma rays from space.[11] The effort to establish the facility is led by Bhaba Atomic Research Center in collaboration with Tata Institute of Fundamental Research, Indian Institute of Astrophysics, Bangalore and Saha Institute of Nuclear Physics, Kolkata. The facility is estimated to cost Rs. 400 million.[11] Once completed it will be the only such facility in the eastern hemisphere.[11] As of June 2014 the telescope has been fabricated by the Electronics Corporation of India and is being installed at the IAO.[12] Once installed, this Telescope will be the second largest gamma ray telescope in the world and the world's largest telescope at the highest altitude.