相关论文: Roll Angle Adjustment Dims Starlink Satellites

In the era of mega-constellations, the need for accurate and publicly available information has become fundamental for satellite operators to guarantee the safety of spacecrafts and the Low Earth Orbit (LEO) space environment. This study…

The Steward Observatory LEO Satellite Photometric Survey is a comprehensive observational survey to characterize the apparent brightness of the Starlink and OneWeb low Earth orbit satellites and evaluate the potential impact on astronomy.…

We present new spectroscopic and photometric observations of the HAT-P-1 planetary system. Spectra obtained during three transits exhibit the Rossiter-McLaughlin effect, allowing us to measure the angle between the sky projections of the…

The rapid growth of satellite constellations, particularly Starlink, is increasingly affecting ground-based astronomy. In this project, we developed a workflow to detect, identify, and measure the brightness of trails from artificial…

We present Faraday Rotation Measure (RM) properties of seven active galactic nuclei (AGN), observed with the NRAO VLA at three epochs in 2012-2014. Data was taken at 1.4, 2.2, 5.0, 8.2, 15.4, 22.4, 33.5 and 43.1 GHz quasi simultaneously in…

Artificial satellites perform downlink communication or transmission with earth stations. These transmissions are made from an array of antennas chosen to increase directivity and gain in the transmission of the electromagnetic signal. It…

Measuring photometric brightness is a common tool for characterizaing satellites. However, characterizing satellite mega-constellations and their impact on astronomy research requires a new approach and methodology. A few measurements of…

The BlueWalker 3 (BW3) satellite was folded into a compact object when launched on 2022 September 11. The spacecraft's apparent visual magnitude initially ranged from about 4 to 8. Observations on November 11 revealed that the brightness…

We calculated the median parallaxes for 47 OB associations including at least 10 stars with known Gaia DR2 parallaxes. A comparison between trigonometric and photometric parallaxes of OB associations reveals a zero-point offset of…

We report the measurement results and compensation of the antenna elevation angle dependences of the Sub-millimeter Array (SMA) antenna characteristics. Without optimizing the subreflector (focus) positions as a function of the antenna…

We study the dependence of satellite galaxy properties on the distance to the host galaxy and the orbital motion using the SDSS data. From SDSS DR7 we find 3515 isolated satellite systems of galaxies at z<0.03 that contain 8904 satellite…

The high accuracy reached by solar limb observations, by helioseismic measurements and by Standard Solar Models (SSMs) calculations suggests that general relativity corrections are included when discussing the solar radius. The Allen value…

This paper analyses the relativistic stellar aberration requirements for the Space Interferometry Mission (SIM). We address the issue of general relativistic deflection of light by the massive self-gravitating bodies. Specifically, we…

In the summer of 2011, the first on-sky astrometric commissioning of PRIMA-Astrometry delivered a performance of 3 m'' for a 10 '' separation on bright objects, orders of magnitude away from its exoplanet requirement of 50 {\mu}'' ~ 20…

The lensing effect of curved space, which can cause the angular diameter of a fixed reference length seen on the sky to reach a minimum and then increase with redshift, depends sensitively on the value of the cosmological constant,…

We re-analyse the subset of the Faraday rotation measures data from the NRAO VLA Sky Survey catalogue for which redshift and spectral index information is available, in order to better elucidate the relations between these observables. We…

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…

SARLink is a passive satellite backscatter communication system that uses existing spaceborne synthetic aperture radar (SAR) imaging satellites to provide connectivity in remote regions. It achieves orders of magnitude more range than…

Star sensor's image plane can have three kinds of displacement after a long time working in space, and the displacements are the principal point drift, incline displacement and rotation displacement. These displacements can severely…

With the objective of exploiting hardware capabilities and preparing the ground for the next-generation X-band synthetic aperture radar (SAR) missions, TerraSAR-X and TanDEM-X are now able to operate in staring spotlight mode, which is…