Results 71 to 80 of about 31,207 (206)

Reassessing the Relationship Between Meteor Radio Afterglows and Optical Persistent Trains

open access: yesJournal of Geophysical Research: Space Physics, Volume 130, Issue 9, September 2025.
Abstract Meteor radio afterglows (MRAs) and optical persistent trains (PTs) are two types of long‐lived phenomena which are occasionally observed following the occurrence of a meteor. Both phenomena are thought to be produced by intrinsic emission mechanisms; PTs have been associated with chemiluminescent reactions between meteoric metals and ...
L. E. Cordonnier   +5 more
wiley   +1 more source

The GAPS programme at TNG

open access: yesAstronomy & Astrophysics
Context. The transition regime between giant planets (GPs) and brown dwarfs (BDs) is still an open subject of study in exoplanetary science. A complete understanding of the population of long-period GPs and BDs would be pivotal for improving our ...
Pinamonti M.   +26 more
doaj   +1 more source

A DIFFERENTIAL CATALOGUE OF RIGHT ASCENSIONS OF 263 RRS2 STARS OBTAINED FROM OBSERVATIONS MADE WITH THE ODESSA MERIDIAN CIRCLE IN 1990-1993

open access: yesOdessa Astronomical Publications, 2017
This catalogue contains the results of 1321 right ascensions observations of 2dj Radio References Stars obtained al Odessa with the Repsold transit circle in 1990-1993.
A. P. Chelombit'ko
doaj   +1 more source

Constraining the size, shape, and albedo of the large trans-Neptunian object (28978) Ixion with multi-chord stellar occultations

open access: yesAstronomy & Astrophysics
Context. Trans-Neptunian objects (TNOs) are among the most primitive remnants of the early Solar System. Determining their sizes, shapes, albedos, and surface properties is essential for understanding their origin and evolution.
Kilic Y.   +83 more
doaj   +1 more source

Astrometric Methods and Instrumentation to Identify and Characterize Extrasolar Planets: A Review

open access: yes, 2005
I present a review of astrometric techniques and instrumentation utilized to search for, detect, and characterize extra-solar planets. First, I briefly summarize the properties of the present-day sample of extrasolar planets, in connection with ...
Alessandro Sozzetti   +33 more
core   +2 more sources

Speckle Observations With PISCO in Calern (France): II. Astrometric Measurements of Visual Double Stars in 2017–2018 and New or Revised Orbits for A1913 AB, A1710, COU1394, BU1185, A122, A570, HU577, COU812, HU332, A2095 AB, and A884

open access: yesAstronomische Nachrichten, Volume 346, Issue 6, July 2025.
ABSTRACT We present relative astrometric measurements of visual double stars, made in 2017–2018 with the speckle camera PISCO at the 1‐m Epsilon telescope of the C2PU facility (Observatoire de la Côte d'Azur, Calern site). Our observing list contains orbital couples as well as double stars whose motion is still uncertain.
M. Scardia   +11 more
wiley   +1 more source

Measuring Titan’s rapid orbital expansion combining Cassini radio science normal points and astrometry

open access: yesAstronomy & Astrophysics
Recent analyses of Titan’s orbital migration have yielded conflicting results regarding Saturn’s tidal dissipation (Q) at Titan’s frequency. While some studies reported a low Q consistent with resonance locking using independent radio science and ...
Magnanini Andrea   +4 more
doaj   +1 more source

Uncertainties in Ground‐Based Visual Double Star Measures—II Accuracy of Measures

open access: yesAstronomische Nachrichten, Volume 346, Issue 6, July 2025.
ABSTRACT Letchford and White 2025, Paper I, determined the uncertainties in ground‐based historic measures of double stars. In this paper, the accuracy of 26,205 ground‐based measures of 857 visual double stars, made since ∼$$ \sim $$1780, is determined relative to space‐based measures based on positions and proper motion from the HIPPARCOS (via ASCC ...
Graeme L. White, Roderick R. Letchford
wiley   +1 more source

Astrometric microlensing probes of the isolated neutron star population with Roman

open access: yesAstronomy & Astrophysics
Context. Notoriously hard to detect and study, isolated neutron stars (NSs) might provide valuable answers to fundamental questions about stellar evolution and explosion physics.
Kaczmarek Z.   +4 more
doaj   +1 more source

Deep Space Network Radio Science and Ground‐Based Planetary Radar in the Next Decade

open access: yesRadio Science, Volume 60, Issue 7, July 2025.
Abstract The Deep Space Network (DSN) has been a core operational element of NASA's crewed and robotic exploration of the Solar System since the early 1960s. The primary role of the DSN has been to acquire telemetry and navigation data, but over the years, its radiometric and radar capabilities have expanded to form a system for obtaining unique ...
R. S. Park   +13 more
wiley   +1 more source

Home - About - Disclaimer - Privacy