相关论文: BlueWalker 3 Satellite Brightness Characterized an…

The apparent brightness of satellites is calculated as a function of satellite position as seen by a ground-based observer in darkness. Both direct illumination of the satellite by the Sun as well as indirect illumination due to reflection…

3I/ATLAS was discovered on UT 2025 July 1 and joins a limited but growing population of detected $\sim10^2-10^3$ m scale interstellar objects. In this paper we report photometric observations of 3I/ATLAS from the nights of UT 2025 July 3,…

Photometric characteristics for all models of Starlink satellites launched to date are reviewed. The Original design that lacked brightness mitigation is the most luminous. SpaceX installed a sunshade on the VisorSat model which reduced its…

Interstellar comet 3I/ATLAS has been approaching its 2025 October 29 perihelion while opposite the Sun from Earth, hindering ground-based optical observations over the preceding month. However, this geometry placed the comet within the…

The illumination phase functions for Starlink Mini satellites are determined for times of twilight and darkness. Those functions are then evaluated to give apparent magnitudes over a grid of points across the sky and over a range of solar…

The mean apparent magnitude of Starlink Mini Direct-To-Cell (DTC) satellites is 4.62 while the mean of magnitudes adjusted to a uniform distance of 1000 km is 5.50. DTCs average 4.9 times brighter than other Starlink Mini spacecraft at a…

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…

On 8 April 2024, tens of millions of people across North America will be able to view a total solar eclipse. Such astronomical events have been important throughout history, but with nearly 10,000 satellites in orbit, we question whether…

In 2022 the BL Lac object S4 0954+65 underwent a major variability phase, reaching its historical maximum brightness in the optical and $\gamma$-ray bands. We present optical photometric and polarimetric data acquired by the Whole Earth…

It is widely believed that the large discrepancy between the observed number of satellite galaxies and the predicted number of dark subhalos can be resolved via a variety of baryonic effects which suppress star formation in low mass…

We report initial observations aimed at the characterization of a third interstellar object. This object, 3I/ATLAS or C/2025 N1 (ATLAS), was discovered on 2025 July 1 UT and has an orbital eccentricity of $e\sim6.1$, perihelion of $q\sim…

Observations on comet C/2007 N3 (Lulin) were made at phase angles close to opposition ($1.7^{\circ}$ - $10^{\circ}$). Photometric observations were carried out during 2009 February 24-28, in the IHW blue and red continuum and $R$ broad band…

The mean apparent magnitude of Amazon Leo satellites is 6.28 based on 1,938 observations. For spacecraft in their operational mode, 92% exceeded the brightness limit recommended by the IAU for interference with research, while 25% distract…

We study the apparent optical brightness of satellite streaks in ground-based observatory cameras as the orbit height is varied. This is done via simulations. Several factors are in play: the range to the satellite, satellite size and…

We present a coordinated campaign of observations to monitor the brightness of the James Webb Space Telescope (JWST) as it travels toward the second Earth-Sun Lagrange point and unfolds using the network ofUnistellar digital telescopes.…

The rapid increase in satellite launches in recent years, and the pressure of launches planned into the next decade, demands an improvement in the efficiency of space domain awareness facilities. Optical facilities form an important…

A model of the brightness of the visorsat Starlink spacecraft is presented based on published information on the engineering design and from analysis of 131 observations of individual visorsats in late 2020. Comments are offered on the…

We present optical and ultraviolet observations of 3C273 covering the whole life of the IUE satellite. We analyze the variability properties of the light curves, and find that two variable components, written B and R respectively, must…

The brightness of Starlink satellites during orbit parking and orbit raising decreased significantly in 2020 when the operator modified their orientation. The mean apparent magnitude before the change was 3.90 +/- 0.18, while afterward it…

Brightness statistics for satellites of the Starlink, BlueBird, Qianfan, Guowang and OneWeb constellations are reported. The means and standard deviations are compared to acceptable limits set by the International Astronomical Union's…