Related papers: Optimal stellar photometry for multi-conjugate ada…
We have developed the techniques required to use the optimal photometry algorithm of Naylor (1998) to create colour-magnitude diagrams with well defined completeness functions. To achieve this we first demonstrate that the optimal…
As one of the most widely recognized high-quality standard stars, the Stetson standards have been extensively used as a photometric reference for calibrating other surveys. In this work, we present an independent validation and…
Adaptive optical correction is an efficient technique to obtain high-resolution images of the retinal surface. A main limitation of adaptive optical correction, however, is the small size of the corrected image. For medical purposes it is…
Astronomical telescopes suffer from a tradeoff between field of view (FoV) and image resolution: increasing the FoV leads to an optical field that is under-sampled by the science camera. This work presents a novel computational imaging…
One of the possible approaches to detecting optical counterparts of GRBs requires monitoring large parts of the sky. This idea has gained some instrumental support in recent years, such as with the "Pi of the Sky" project. The broad sky…
MICADO is the Multi-AO Imaging Camera for Deep Observations, and it will be one of the first light instruments of the Extremely Large Telescope (ELT). Doing high precision multi-object differential astrometry behind ELT is particularly…
Extreme adaptive optics systems are now in operation across the globe. These systems, capable of high order wavefront correction, deliver Strehl ratios of 90% in the near-infrared. Originally intended for the direct imaging of exoplanets,…
We describe a first attempt to apply adaptive optics to the study of resolved stellar populations in galaxies. Advantages over traditional approaches are (i) improved spatial resolution and point-source sensitivity through adaptive optics,…
Astrometry is one of the main pillars of astronomy, and one of its oldest branches. Over the years, an increasing number of astrometric works by means of Hubble Space Telescope (HST) data have revolutionized our understanding of various…
The current direct observations of brown dwarfs and exoplanets have been obtained using instruments not specifically designed for overcoming the large contrast ratio between the host star and any wide-separation faint companions. However,…
Using the adaptive optics facilities at the 200-in Hale and 10-m Keck II, we observed in the near infrared a sample of 12 binary and multiple stars and one open cluster. We used the near diffraction limited images of these systems to…
The Next Generation Space Telescope (NGST) will gather unprecedented spectro-photometric data on galaxies out to the highest redshifts. It is therefore crucial to identify the spectro-photometric diagnostics within reach of NGST, which will…
We discuss the system requirements for obtaining millimagnitude photometric precision over a wide field using small aperture short focal length telescope systems, such as are being developed by a number of research groups to search for…
We present a new technique for monitoring microlensing activity even in highly crowded fields, and use this technique to place limits on low-mass MACHOs in the haloes of M31 and the Galaxy. Unlike present Galactic microlensing surveys, we…
The Multi-adaptive optics Imaging CamerA for Deep Observations (MICADO) will image a field of view of nearly 1 arcminute at the diffraction limit of the Extremely Large Telescope (ELT), making use of the adaptive optics correction provided…
We explore the possibility of detecting very faint, very close-in stellar companions using large aperture ground-based telescopes and the technique of optical speckle imaging. We examine the state of high angular resolution speckle imaging…
The stellar mass-luminosity relation is poorly constrained by observations for high mass stars. We describe our program to find eclipsing massive binaries in the Magellanic Clouds using photometry of regions rich in massive stars, and our…
High-performance instruments at large ground-based telescopes have made integral field spectroscopy (IFS) a powerful tool for the study of extended objects such as galaxies, nebulae, or even larger survey fields on the sky. Here we discuss…
Deriving stellar atmospheric parameters and chemical abundances from stellar spectra is crucial for understanding the evolution of the Milky Way. By performing a fitting with MARCS model atmospheric theoretical synthetic spectra combined…
We present the results from a three night, time-series study of the open cluster NGC 6791 using the Megacam wide-field mosaic CCD camera on the 6.5m MMT telescope. The aim of this study was to demonstrate the ability to obtain very high…