相关论文: Performance of a speckle interferometer

A new optical speckle interferometer for use at the 2.34 meter Vainu Bappu Telescope (VBT), at Vainu Bappu Observatory (VBO), Kavalur, India, has been designed and developed. Provisions have been made for observation both at the prime focus…

Speckle interferometric technique is employed to record a series of hundreds of short-exposure images of several close binary stars with sub-arcsecond separation through a narrow band filter at the Cassegrain focus of the 2.34 meter (m)…

We have presented the basic mathematical treatment of interferometry in the optical domain. Its applications in astronomical observations using both the single aperture, as well as the diluted apertures are described in detail. We have also…

Speckle interferometric technique is used to record a series of short exposure images of several close binary stars with sub-arcsecond separation through a narrow band filter centred at H$\alpha$ at the Cassegrain focus of the 2.34 meter…

The 2.34m Vainu Bappu Telescope (VBT) is a reflecting telescope that operates in two modes, prime focus and cassegrain focus, and is equipped with two instruments. In prime focus mode, the telescope has the F-number of f/3.25, and the…

A fiber-fed Echelle spectrograph at 2.3 m Vainu Bappu Telescope (VBT), Kavalur, has been in operation since 2005. Owing to various technological advancements in precision spectroscopy in recent years, several research avenues have been…

We developed a tip-tilt system to compensate the turbulence induced image motion for 1.3 m telescope at Vainu Bappu Observatory, Kavalur. The instrument is designed to operate at visible wavelength band (480-700 nm) with a field of view…

The Echelle spectrograph operating at Vainu Bappu Telescope (VBT) is a general purpose instrument designed for high resolution spectroscopy. It is being considered for precision Doppler measurements without altering the existing design and…

We report the atmospheric turbulence parameters namely, atmospheric seeing, the tilt-anisoplanatic angle ($\theta_0$) and the coherence time ($\tau_0$), measured under various sky conditions, at Vainu Bappu Observatory in Kavalur. Bursts of…

Transmission spectroscopy has proven to be an effective technique for characterizing exoplanet atmospheres. However, transmission spectroscopy requires planetary transits, which occur for only a small fraction of planetary systems due to…

The Echelle spectrograph operating at Vainu Bappu Telescope (VBT), India, is a general purpose instrument used for many high-resolution spectroscopic observations. A concerted effort is being made to expand the scientific capability of the…

The Vainu Bappu Telescope (VBT) is a 2.34-m reflector, primarily supported on-axis field of view, offering high-resolution and low-to-medium resolution spectroscopic observations in its prime and Cassegrain configurations. This study…

The present generation of ground-based Very High Energy (VHE) gamma-ray observatories consist of arrays of up to four large (> 12m diameter) light collectors quite similar to those used by R. Hanbury Brown to measure stellar diameters by…

The balloon-borne very long baseline interferometry (VLBI) experiment is a technical feasibility study for performing radio interferometry in the stratosphere. The flight model has been developed. A balloon-borne VLBI station will be…

The imminent availability of large arrays of large light collectors deployed to exploit atmospheric Cherenkov radiation for gamma-ray astronomy at more than 100GeV, motivates the growing interest in application of intensity interferometry…

Conventional ground-based optical telescopes, even those with large apertures, primarily observe stars, close binaries, and multiple systems as unresolved point sources through photometric measurements. Spectroscopy can identify multiple…

This article begins with the discussions on the formation of speckles in the case of non-coherent quasi monochromatic source and of ways to detect them. Prior to this, a brief introduction on the behavior of the atmosphere and its effect on…

Intensity interferometry exploits a quantum optical effect in order to measure objects with extremely small angular scales. The first experiment to use this technique was the Narrabri intensity interferometer, which was successfully used in…

Imaging Atmospheric Cherenkov Telescopes have long been viewed as potential light collectors to be used for long baseline optical intensity interferometry observations. Intensity interferometry, as implemented with Cherenkov telescopes, is…

We present a feasibility study exploring the implementation of optical interferometry and speckle techniques with the 1.3-m Devasthal Fast Optical Telescope (DFOT) at ARIES, which is currently dedicated to photometric observations. Using…