Increasing levels of Radio Frequency Interference (RFI) are a problem for research in radio astronomy. Various techniques to suppress RFI and extract astronomical signals from data affected by interference are being tried out. However, extracting weak astronomical signals in the spectral region affected by RFI remains a technological challenge. In this paper, we describe the construction of an ...

Effective radio frequency interference (RFI) cancellation for spectroscopic applications can take place using time averaged spectra. An RFI “reference signal,” constructed from the cross power spectrum of the signals from the two polarizations of a reference horn pointed at the source of the RFI signal, in combination with cross power spectra with the signals from the Parkes telescope, allows c...

The MACHO Project is a microlensing survey that monitors the brightnesses of ∼60 million stars in the Large Magellanic Cloud (LMC), Small Magellanic Cloud, and Galactic bulge. Our database presently contains about 80 billion photometric measurements, a significant fraction of all astronomical photometry. We describe the calibration of MACHO two-color photometry and transformation to the standar...

Multimode fibres are widely used in astronomy because of the ease of coupling light into them at a telescope focus. The photonics industry has given rise to a broad range of products but these are almost exclusively restricted to single-mode fibres, although some can be adapted for use in fibres that allow several modes to propagate. Now that astronomical telescopes are moving toward diffractio...

A direct measurement of the universe's expansion history could be made by observing in real time the evolution of the cosmological redshift of distant objects. However, this would require measurements of Doppler velocity drifts of approximately 1 centimeter per second per year, and astronomical spectrographs have not yet been calibrated to this tolerance. We demonstrated the first use of a lase...

At the Venezuela National Astronomical Observatory we are carrying out variability surveys spanning many hundreds of square degrees near the celestial equator, using an 8k x 8k CCD Mosaic Camera optimized for drift-scanning on a 1m Schmidt telescope. Among the initial efforts was a project to obtain the first moderately deep, homogeneous sample of young stars over an area of ∼ 180sqr.deg. encom...

Hiroi, A. Kanno, R. Nakamura, M. Abe, M. Ishiguro, S. Hasegawa, S. Miyasaka, T. Sekiguchi, H. Terada, and G. Igarashi, Dept. of Geological Sciences, Brown University, Providence, RI 02912, USA., Dept. of Earth & Planetary Science, Graduate School of Science, The University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo 1130033, Japan, Lunar Mission Research Center, National Space Development Agency o...

The mean velocity of the atmospheric wind is an important parameter in characterizing the turbulence above an astronomical telescope. Real-time wind velocity measurement is exceedingly essential to update the design metrics of the adaptive optics system periodically to improve the dynamic performance. A Shack Hartmann Wavefront Sensor (SHWS), which is generally used in astronomical telescope ad...

Lunar Laser Ranging (LLR) is the only means available for testing Einstein’s Strong Equivalence Principle, on which general relativity rests. LLR also provides the strongest limits to date on variability of the gravitational constant, the best measurement of the de Sitter precession rate, and is relied upon to generate accurate astronomical ephemerides. LLR is poised to take a dramatic step for...

Based on photographic plates obtained with 2m RCC telescope at National Astronomical Observatory Rozhen (Bulgaria) we inspected an area of ~1 sq.degree in the direction of the Hercules void with automatic object detection software. As our first result we present a list of ~1800 detected galaxies in the wide range of magnitudes 13≤B≤21 and effective surface brightnesses 16≤μeff(B) ≤ 24 mag arcse...