Results 121 to 130 of about 41,651 (296)

Uncertainties in Ground‐Based Visual Double Star Measures

Astronomische Nachrichten, Volume 346, Issue 2, February 2025.
ABSTRACT Stellar masses are found from the orbital elements of binary systems which are, in turn, computed from weighted astrometric measures. Astrometric measures of double stars (their position angle and separation) rarely include uncertainties, and published binary star orbits rarely include the weighting systems used in the determination of the ...
Roderick R. Letchford, Graeme L. White
wiley   +1 more source

Integrity Assessment and Verification Procedure of Angle-only Data for Low Earth Orbit Space Objects with Optical Wide-field PatroLNetwork (OWL-Net)

Journal of Astronomy and Space Sciences, 2019
The Optical Wide-field patroL-Network (OWL-Net) is a global optical network for Space Situational Awareness in Korea. The primary operational goal of the OWL-Net is to track Low Earth Orbit (LEO) satellites operated by Korea and to monitor the ...
Jin Choi, Jung Hyun Jo, Sooyoung Kim
doaj   +1 more source

Astrometry with the Keck-Interferometer: the ASTRA project and its science

, 2008
The sensitivity and astrometry upgrade ASTRA of the Keck Interferometer is introduced. After a brief overview of the underlying interferometric principles, the technology and concepts of the upgrade are presented.
Andrea M. Ghez, Andrew Cooper, Ben Berkey, Bill Randolph, Boden, Bouchez, Brett Smith, Colavita, Colavita, Colavita, Colette Tyau, Delplancke, Douglas Morrison, Drew Medeiros, Ed Wetherell, Eisner, Eliot Quataert, Esposito, Ghez, Ghez, Gillessen, Gilmozzi, Haniff, James R. Graham, John Monnier, Jorg-Uwe Pott, Josh A. Eisner, Julien Woillez, Kellee Summers, Kevin Tsubota, Labeyrie, Lynne Hillenbrand, Mark M. Colavita, Michael Hrynewych, Monnier, Nevin Weinberg, Peter L. Wizinowich, Pott, Rachel L. Akeson, Rafael Millan-Gabet, Santos, Shao, Tatyana Panteleeva, Vasisht, Weigelt   +44 more
core   +1 more source

Astrometry and Relativity

arXiv: Astrophysics, 2005
General relativistic effects in astrophyiscal systems have been detected thanks to accurate astrometric measurements. We outline some keystones of astrometry such as stellar aberration (argument development during the years 1727-1872); Mercury's perihelion precession (1845-1916); solar disk oblateness (1966-2001); relativistic light deflection (1916 ...
openaire   +3 more sources

JWST Imaging of the Closest Globular Clusters—V. The White Dwarfs Cooling Sequence of M4

Astronomische Nachrichten, Volume 346, Issue 2, February 2025.
ABSTRACT We combine infrared (IR) observations collected by the James Webb Space Telescope with optical deep images by the Hubble Space Telescope taken ~20 years earlier to compute proper‐motion membership for the globular cluster (GC) M4 (NGC 6121) along its entire white dwarf (WD) cooling sequence (CS).
Luigi R. Bedin, Mattia Libralato, Maurizio Salaris, Domenico Nardiello, Michele Scalco, Massimo Griggio, Jay Anderson, Pierre Bergeron, Andrea Bellini, Roman Gerasimov, Adam J. Burgasser, Daniel Apai   +11 more
wiley   +1 more source

Revisiting Variable Stars Near Globular Clusters South of −29° Declination

Astronomische Nachrichten, Volume 346, Issue 2, February 2025.
ABSTRACT We review an often‐cited but seldom‐accessed catalogue by Fourcade and Laborde (1966) of 785 variable stars near 47 southern Galactic globular clusters, and recover the locations of 85 stars that were not incorporated into subsequent variable star catalogues and hence have become “lost” to the literature.
Andrew C. Layden, Julia Evangelista, Sakshi Gupta, Mithilesh Mittameda, Eva Mulloy, Sohan I. Muslim, Tiyinoluwa Olushola‐Alao, Akul Rishi   +7 more
wiley   +1 more source

Preimpact Detection of Chelyabinsk‐Type Objects in the Thermal Infrared: Possibilities and Limitations

Advances in Astronomy, Volume 2025, Issue 1, 2025.
The Chelyabinsk meteor entered Earth’s atmosphere on 15 February 2013, producing a shock wave that injured about 1500 people and damaged thousands of buildings. Despite its relatively large size (∼20 m), the progenitor asteroid approached Earth undetected. Its apparent radiant was too close to the Sun for standard ground‐based near‐Earth asteroid (NEA)
Thomas Müller, Luca Conversi, Javier Licandro, Marco Delbo, Alan Fitzsimmons, Karri Muinonen, Marcel Popescu, Paolo Tanga, Richard Moissl, Michael Kueppers   +9 more
wiley   +1 more source

Nature in Seclusion. The Monastic Republic of Letters in Southern Germany**

Berichte zur Wissenschaftsgeschichte, Volume 47, Issue 3, Page 215-241, September 2024.
Abstract Monasteries were famous for their extensive libraries and richly decorated churches. Less well known are their observatories and their mathematical‐physical collections with telescopes, air pumps, and friction machines. But how did the way of life in the monastery and scientific practices influence each other?
Julia Bloemer
wiley   +1 more source

PHASES High Precision Differential Astrometry of delta Equulei

, 2005
delta Equulei is among the most well-studied nearby binary star systems. Results of its observation have been applied to a wide range of fundamental studies of binary systems and stellar astrophysics.
Aristidi E., Balega I., Balega I. I., Balega I. I., Balega I. I., Balega Y. Y., Benjamin F. Lane, Bernard F. Burke, Boehm C., Bonneau D., Bonneau D., Castelli F., Couteau P., Couteau P., Couteau P., Danjon A., Docobo J. A., Duquennoy A., Finsen W. S., Finsen W. S., Finsen W. S., Finsen W. S., Finsen W. S., Finsen W. S., Finsen W. S., Habets G. M. H. J., Heintz W. D., Holden F., Ismailov R. M., Isobe S., Jeffers H. M., M. M. Colavita, M. Shao, Maciej Konacki, Matthew W. Muterspaugh, Miura N., Morgan B. L., Morgan B. L., Muller P., Muller P., Rabl G., S. R. Kulkarni, Smalley B., Soderhjelm S., Starikova G. A., Struve O., Tokovinin A. A., Tokovinin A. A., Tokovinin A. A., Tokovinin A. A., van den Bos W. H., van Leeuwen F., Wilson R. H., Wilson R. H., Wilson R. H.   +54 more
core   +1 more source

Multi‐Instrument and SAMI3‐TIDAS Data Assimilation Analysis of Three‐Dimensional Ionospheric Electron Density Variations During the April 2024 Total Solar Eclipse

Journal of Geophysical Research: Space Physics, Volume 129, Issue 9, September 2024.
Abstract This paper conducts a multi‐instrument and data assimilation analysis of the three‐dimensional ionospheric electron density responses to the total solar eclipse on 08 April 2024. The altitude‐resolved electron density variations over the continental US and adjacent regions are analyzed using the Millstone Hill incoherent scatter radar data ...
Ercha Aa, Joseph Huba, Shun‐Rong Zhang, Anthea J. Coster, Philip J. Erickson, Larisa P. Goncharenko, Juha Vierinen, William Rideout   +7 more
wiley   +1 more source