Related papers: Starlink Satellite Brightness Before VisorSat

The number of artificial satellites in Low Earth Orbit (LEO) is increasing at an exponential rate since 2019. Satellites are visible to both ground and space telescopes, and their bright emission in optical, infrared, and radio-wavelengths…

In the gravitational lens system B1600+434 the brighter image, A, is known to show rapid variability which is not detected in the weaker image, B (Koopmans & de Bruyn 2000). Since correlated variability is one of the fundamental properties…

We report on one year of photometric monitoring of the ultraluminous BAL quasar APM 08279+5255. The temporal sampling reveals that this gravitationally lensed system has brightened by ~0.2 mag in 100 days. Two potential causes present…

We present measurements of sky surface brightness and seeing on Mt.Graham obtained at the Vatican Advanced Technology Telescope (VATT) during 16 observing runs between April 1999 and December 2003. We show that the sky surface brightness is…

The North American Aerospace Defense Command (NORAD) tracking of the SpaceX Starlink satellite launch on February 03, 2022 is reviewed. Of the 49 Starlink satellites released into orbit, 38 were eventually lost. Thirty-two of the satellites…

Gravitational wave events with electromagnetic counterparts provide direct measurements of the Hubble diagram. We demonstrate that incorporating weak lensing into bright standard siren analyses allows measurements of cosmological parameters…

Although low surface brightness galaxies (LSBs) contribute a large fraction to the number density of galaxies, their properties are still poorly known. LSBs are often considered dust poor, based only on a few studies. We use, for the first…

The proposed VLA Sky Survey (VLASS) comprises two distinct S-band (2--4 GHz) surveys: (1) All-Sky covering the sky north of -40 deg with rms noise 69 microJy/beam = 1.5 K in the 2.5 arcsec beam and (2) Deep covering 10 square deg with rms…

The observed Galactic rate of stellar mergers or the initiation of common envelope phases brighter than M_V=-3 (M_I=-4) is of order 0.5 (0.3)/year with 90% confidence statistical uncertainties of 0.24-1.1 (0.14-0.65) and factor of 2…

Artificial satellites orbiting around the Earth, under certain conditions, result to be visible even to the naked eye. The phenomenon of light pollution jeopardises the researching activities of the astronomical community: traces left by…

This study investigates the orbital decay and subsequent reentries of 12 Starlink satellites from 16 April to 15 May 2024. By examining Two-Line Element data, we observed a significant increase in orbital decay following the geomagnetic…

The variability of blazars in the X-ray and optical regions informs both the physics of their emitting region and places demands on the observer if a program requires that the object be bright or faint. The extensive simultaneous X-ray and…

We present here the characterization of the night sky-brightness at the near-infrared, the telescope seeing, and the fraction of useful time at the Calar Alto observatory. For this study we have collected a large dataset comprising 7311…

Using LAMOST spectroscopic data, we find a strong signal of a comoving group of stars in the constellation of Draco. The group, observed near the apocenter of its orbit, is 2.6 kpc from the Sun with a metallicity of -0.64 dex. The system is…

We present a new procedure for photometric parallax estimation. The data for 1236 stars provide calibrations between the absolute magnitude offset from the Hyades main-sequence and the UV-excess for different (B-V)o colour-index intervals,…

Uranus is fainter when the Sun and Earth are near its equatorial plane than when they are near the projection of its poles. The average of the absolute values of the sub-Earth and sub-Sun latitudes (referred to as the sub-latitude here) is…

We present polarisation observations of the gravitational lens system B1422+231 made at 8.4 GHz using the VLBA and the 100m telescope at Effelsberg. All four images of the quasar show structure on the milliarcsec scale. The three bright…

From theoretical predictions, the introduction of 8-m class telescopes permits one to extend Surface Brightness Fluctuations measurements from the ground to ~7000 km/s, with a precision that is comparable to current space-based…

We have used FUSE and Voyager observations of dust scattered starlight in the neighborhood of the Coalsack Nebula to derive the optical constants of the dust grains. The albedo is consistent with a value of $0.28 \pm 0.04$ and the phase…

We conduct a comprehensive and statistical study of the luminosity functions (LFs) for satellite galaxies, by counting photometric galaxies from HSC, DECaLS and SDSS around isolated central galaxies (ICGs) and paired galaxies from the…