Optical Telescopes at Devasthal Observatory, Nainital

Sagar, Ram

doi:10.1007/s12045-020-1072-1

Cited by 2 publications

(2 citation statements)

References 36 publications

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“…The images in our dataset were captured by the 1.3-m Devasthal Fast Optical Telescope (DFOT) in the observatory of the Arybhatta Research Institute of Observational Sciences (ARIES) in Nainital, India [ARItea, ARIteb,Sea11]. The datasets used in this paper were derived from a project at ARIES [Agr21].…”

Section: Devasthal Fast Optical Telescope (Dfot)mentioning

confidence: 99%

Image Classification of Stars and Galaxies Using Different Machine Learning Models

Leifer

2023

Preprint

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The correct classification of astronomical objects -such as stars and galaxies -is essential to the field of astronomy. Today, however, with the advent of powerful next generation telescopes, the quantity of images being collected far exceeds the amount that can be catalogued by astronomers through their own observations and analyses alone. As just one example, the Large Synoptic Survey Telescope ("LSST"), opening in August 2024, will catalogue around 40 billion images of stars and galaxies. Certain machine learning models have proven efficient and accurate in classifying astronomical images. In this paper, we tested the ability of four different machine learning models to classify images of stars and galaxies accurately without inputs of additional measurements of the brightness, size, or shape of stars or galaxies: a convolutional neural network ("CNN") model, a logistic regression model, a random forest classifier, and a small neural network. We discuss and compare the architecture and performance of each model. We found that our neural network model trained on a data set preprocessed using a data preprocessing technique known as Principal Component Analysis ("PCA"), performed the best achieving an accuracy of 84 percent out of sample. We thus demonstrate that using such machine learning models can be an effective way to classify images of stars and galaxies, substantially reducing the time required to catalogue them.

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Section: Devasthal Fast Optical Telescope (Dfot)mentioning

confidence: 99%

Image Classification of Stars and Galaxies Using Different Machine Learning Models

Leifer

2023

Preprint

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“…The site offers over 200 spectroscopic nights in a year out of which ∼ 80% are of photometric quality. The Devasthal site became an Observatory in 2010 when 1.3-m DFOT was successfully installed and commissioned 16,22 . It is worth mentioning here that till recently, there was no knowledge about nearinfrared (NIR) properties of the site.…”

Section: Characterization Of Devasthal Sitementioning

confidence: 99%

The 3.6 meter Devasthal Optical Telescope: From inception to realisation

Sagar,

Kumar,

Omar

2019

Preprint

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India's largest size 3.6 meter Devasthal optical telescope (DOT) was commissioned in the year 2016, though the idea of building it germinated way back in the year 1976. This article provides research accounts as well as glimpses of its nearly four decades of journey. After a decade of site surveys, location of Devasthal in central Himalyan region of Kumaon was identified. Thereafter, a detailed site characterization was conducted and project approvals were obtained. The telescope is designed to be a technologically advanced optical astronomy instrument. It has been demonstrated to resolve a binary star having angular separation of 0. 4. After the technical activation of the telescope on March 30, 2016, it has been in regular use for testing various back-end instruments as well as for optical and near-infrared observations of celestial objects. Back-end instruments used for these observations are 4K×4K CCD imager, Faint object imager cum spectrograph and TIFR nearinfrared camera-II. A few published science results based on the observations taken with the telescope are also presented. Furthermore, the routine observations find that for a good fraction of observing time the telescope provides sky images of sub-arc-second resolution at optical and near-infrared wavelengths. This indicates that the extreme care taken in the design and construction of the telescope dome building has been rewarding since the as-built thermal mass contributes minimally so as not to degrade the natural atmospheric seeing measured at Devasthal about two decades ago during 1997-1999 using differential image motion monitor. The overall on-site performance of the telescope is found to be excellent and at par with the performance of other similar telescopes located over the globe.

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Optical Telescopes at Devasthal Observatory, Nainital

Cited by 2 publications

References 36 publications

Image Classification of Stars and Galaxies Using Different Machine Learning Models

Image Classification of Stars and Galaxies Using Different Machine Learning Models

The 3.6 meter Devasthal Optical Telescope: From inception to realisation

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