Evaluation of Devasthal site for optical astronomical observations

Sagar, Ram; Stalin, C. S.; Pandey, A. K.; Uddin, Wahab; Mohan, V.; Sanwal, B. B.; Gupta, S. K.; Yadav, Rahul; Durgapal, Alok; Joshi, Santosh; Kumar, Brijesh; Gupta, A. C.; Joshi, Y. C.; Srivastava, J. B.; Chaubey, U. S.; Singh, Mahendra; Pant, P.; Gupta, K. G.

doi:10.1051/aas:2000213

Cited by 45 publications

(31 citation statements)

References 10 publications

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“…This site has an average seeing of ≈1 near ground and ≈0.65 at 12 m above the ground (Sagar et al 2000;Stalin et al 2001). We expect these new observing facilities at Devasthal to contribute significantly to asteroseismology in the near future.…”

Section: Analysis Of the Null Resultsmentioning

confidence: 99%

The Nainital-Cape Survey

Joshi¹,

Mary²,

Chakradhari³

et al. 2009

A&A

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Context. The Nainital-Cape survey is a dedicated research programme to search for and study the pulsational variability in chemically peculiar stars in the Northern Hemisphere. Aims. The aim of the survey is to search for such chemically peculiar stars that are pulsationally unstable. Methods. The observations of the sample stars were carried out in high-speed photometric mode using a three-channel fast photometer attached to the 1.04-m Sampurnanand telescope at ARIES. Results. The new photometric observations confirmed that the pulsational period of star HD 25515 is 2.78-hrs. The repeated timeseries observations of HD 113878 and HD 118660 revealed that previously known frequencies are indeed present in the new data sets. We have estimated the distances, absolute magnitudes, effective temperatures and luminosities of these stars. Their positions in the H-R diagram indicate that HD 25515 and HD 118660 lie near the main-sequence while HD 113878 is an evolved star. We also present a catalogue of 61 stars classified as null results, along with the corresponding 87 frequency spectra taken from [2002][2003][2004][2005][2006][2007][2008]. A statistical analysis of these null results shows, by comparison with past data, that the power of the noise in the light curves has slightly increased during the last few years.

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Section: Analysis Of the Null Resultsmentioning

confidence: 99%

The Nainital-Cape Survey

Joshi¹,

Mary²,

Chakradhari³

et al. 2009

A&A

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“…The telescope's primary mirror supported on 69 axial actuators uses the active optics technology, which was originally developed by European Southern Observatory in 1980s for the new technology telescope 5 . The technical details of the DOT and the Devasthal site are provided elsewhere [6][7][8] . The DOT has an internal auto-guider to improve tracking accuracy and a wave-front sensor to align the telescope optics.…”

Section: Introductionmentioning

confidence: 99%

First-Light Images from Low-Dispersion Spectrograph-Cum-Imager on 3.6m Devasthal Optical Telescope

Omar¹,

Kumar²,

Reddy³

et al. 2019

Current Science

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A low dispersion spectrograph-cum-imager has been developed and assembled in ARIES, Nainital. The optical design of the spectrograph consists of a collimator and a focal reducer converting the f/9 beam from the 3.6-m Devasthal optical telescope to a nearly f/4.3 beam. The instrument is capable of carrying out broad-band imaging, narrow-band imaging and low-resolution (λ/Δλ<2000) slit spectroscopy in the wavelength range 350-1050 nm. A closed-cycle cryogenically cooled charge-coupled device camera, also assembled in ARIES, is used as the main imaging device for the spectrograph. The first images from the spectrograph on the telescope assert seeing-limited performance free from any significant optical aberration. An i-band image of the galaxy cluster Abell 370 made using the spectrograph shows faint sources down to ~25 mag. The quality and sensitivity of the optical spectrums of the celestial sources obtained from the spectrograph are as per the expectations from a 3.6-m telescope. Several new modes of observations such as polarimetry, fast-imaging, and monitoring of the atmospheric parameters are being included in the spectrograph. Using a test setup, single optical pulses from the Crab pulsar were detected from the telescope. The spectrograph is one of the main back-end instruments on the 3.6-m telescope for high sensitivity observations of celestial objects.

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“…All stars, deviating blue-ward out of the ZAMS further than 3 a~-v were classified as field stars. We added to our samples some bright stars identified as members of NGC 6611 by Kamp (1974) and by Sagar and Joshi (1979), and as members of M 35 by McNamara and Sekiguchi (1986). Due to the crowding effect on Schmidt plates, these stars were missing in our sample.…”

Section: Cluster Membershipmentioning

confidence: 99%

Schmidt plate survey in the Galactic centre and anticentre direction. Luminosity and mass functions of open clusters

et al. 1998

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The proper motions and stellar magnitudes for more than 20000 stars distributed in areas around eight open clusters in the directions of the Sagittarius-Carina and Perseus spiral arms were used to determine the cluster membership. Both spatial-kinematical and statistical criteria were used for member selection. The luminosity functions of cluster members were constructed and used for the further data improvement. The safest portions of the luminosity function free both from evolved stars and faint field star contamination were used for mass function construction. The composite mass function was derived from the data on five young clusters with log t < 8.2. A dependence of the mass function slope on the adopted input parameters (mass-luminosity relation and distance scale) and on member selection procedure was tested. The slope was found to vary in a range from 1.36 to 1.80 for l g M / M , between 0.3 and 1.2. A possible relation between the individual MF slopes and cluster ages was indicated. The results are in good agreement with published data.

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Evaluation of Devasthal site for optical astronomical observations

Cited by 45 publications

References 10 publications

The Nainital-Cape Survey

The Nainital-Cape Survey

First-Light Images from Low-Dispersion Spectrograph-Cum-Imager on 3.6m Devasthal Optical Telescope

Schmidt plate survey in the Galactic centre and anticentre direction. Luminosity and mass functions of open clusters

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