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Eclipsing binaries with M-type components are still rare objects. Strong observational biases have made that today only a few eclipsing binaries with component masses below 0.6 Msun and well-determined fundamental properties are known.…
This paper presents an analysis of the UV spectrum of some nebulae with clearly identified illuminating stars, all observed by the IUE satellite. The data show remarkable properties of the UV spectrum of the nebulae. Each spectrum is the…
The Faint Sky Variability Survey is aimed at finding photometric and/or astrometric variable objects in the brightness range between 16<V<24 on timescales between tens of minutes and years with photometric precisions ranging from 3…
Using 172 plates taken with the 40-cm astrograph of the Sternberg Astronomical Institute (Lomonosov Moscow University) in 1976-1994 and digitized with the resolution of 2400 dpi, we discovered and studied 275 new variable stars. We present…
We report the results of a diffraction-limited, photometric variability study of the central 5"x5" of the Galaxy conducted over the past 10 years using speckle imaging techniques on the W. M. Keck I 10 m telescope. Within our limiting…
Variable stars play a very important role in our understanding of the Milky Way and the universe. In recent years, many survey projects have generated a large amount of photometric data, necessitating classifiers that can quickly identify…
We have analyzed Beta Pictoris photometric measurements obtained from La Silla by the Geneva Observatory from 1975 to 1992. These data show evidence of variations in the brightness of the star, with no color dependency. Here, we demonstrate…
We present VB, a benchmark that tests whether vision-language models can determine what is and is not visible in a photograph, and abstain when a human viewer cannot reliably answer. Each item pairs a single photo with a short yes/no…
Motivated by the recognition that variation in the optical transmission of the atmosphere is probably the main limitation to the precision of ground-based CCD measurements of celestial fluxes, we review the physical processes that attenuate…
Stellar Intensity Interferometry is a technique based on the measurement of the second order spatial correlation of the light emitted from a star. The physical information provided by these measurements is the angular size and structure of…
Methods of obtaining stellar luminosities (L) have been revised and a new concept, standard stellar luminosity, has been defined. Among the three methods (direct method from radii and effective temperatures, method using a mass-luminosity…
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…
Astrometric surveys such as Gaia and LSST will measure parallaxes for hundreds of millions of stars. Yet they will not measure a single distance. Rather, a distance must be estimated from a parallax. In this didactic article, I show that…
A new analysis of CCD-based BVRI broad-band photometry for the globular cluster NGC2419 is presented, based on 340 CCD images either donated by colleagues or retrieved from public archives. The calibrated results have been made available…
With the advent of space-based precision photometry missions the quantity and quality of starspot light curves has greatly increased. This paper presents a large number of starspot models and their resulting light curves to: 1) better…
We analyze the observability of motion estimates from the fusion of visual and inertial sensors. Because the model contains unknown parameters, such as sensor biases, the problem is usually cast as a mixed identification/filtering, and the…
Video see-through (VST) technology aims to seamlessly blend virtual and physical worlds by reconstructing reality through cameras. While manufacturers promise perceptual fidelity, it remains unclear how close these systems are to…
Having been operational at Kitt Peak for more than a year, the prototype of the Hungarian Automated Telescope (HAT-1) has been used for all-sky variability search of the northern hemisphere. The small autonomous observatory is recording…
The ESA Gaia space astrometry mission will perform an all-sky survey of stellar objects complete in the nominal magnitude range G = [6.0 - 20.0]. The stars with G lower than 6.0, i.e. those visible to the unaided human eye, would thus not…
Large, deep surveys must typically rely on multiband photometry rather than spectroscopy for determining the astrophysical properties (APs) of stars. Yet designing an optimal photometric system for a wide range of objects is complex,…