Results 51 to 60 of about 41,139 (300)
Observations of the Rigollet Comet from Korea and Japan [PDF]
Journal of Astronomy and Space Sciences, 2014 Since Rigollet first discovered a comet in 1939, many follow-up observations have been made, particularly in Europe. It is now known that the Rigollet comet is identical with the one observed by Herschel in 1788, and thus it is now called 35P/1939 O1 ...
Ki-Won Lee +3 more
doaj +1 more source
Bartolomeu Lourenço de Gusmão: o primeiro cientista brasileiro
Revista Brasileira de Ensino de FísicaBartolomeu Lourenço de Gusmão foi o primeiro inventor e cientista brasileiro, célebre pela criação do balão a ar quente em 1709. Nos 300 anos de sua mais famosa invenção, este artigo apresenta uma nova biografia do fundador da Aerostática e um estudo ...
Rodrigo Moura Visoni +1 more
doaj +1 more source
Jurnal Ilmiah Islam Futura, 2017 Data of solar coordinate such as longitude and latitude of the ecliptic, declination, and right ascension are the data that are often involved in astronomical reckoning and practical islamic astronomy.
reza akbar
doaj +1 more source
A tale of two periods: determination of the orbital ephemeris of the super-Eddington pulsar NGC 7793 P13 [PDF]
Astronomy & Astrophysics, 2018 We present a timing analysis of multiple XMM-Newton and NuSTAR observations of the ultra-luminous pulsar NGC 7793 P13 spread over its 65 d variability period.
F. Fuerst +19 more
semanticscholar +1 more source
Analysis of Solar and Lunar Motions in the Seonmyeong Calendar
Journal of Astronomy and Space Sciences, 2019 We investigate solar and lunar motions in the Seonmyeong (SM) calendar that was compiled by Xu, Ang of the Tang dynasty (A.D. 618-907) in China and used for 71 years from 822 to 892.
Ki-Won Lee
doaj +1 more source
Ephemeris Errors and the Gravitational-wave Signal: Harmonic Mode Coupling in Pulsar Timing Array Searches [PDF]
Astrophysical Journal, 2019 Any unambiguous detection of a stochastic gravitational wave background (GWB) by a pulsar timing array will rest on the measurement of a characteristic angular correlation between pulsars.
E. Roebber
semanticscholar +1 more source
Risk, Hazards &Crisis in Public Policy, EarlyView.Abstract Near‐earth orbits are becoming congested because of a rapid growth in the number of satellites and space debris, which presents a real threat to the sustainable use of space and the safety of the Earth. Despite space scientists and public policymakers having been actively seeking solutions for decades, solving the problem has been put off ...
Anna Ya Ni +2 more
wiley +1 more source
Ephemeris of the Satellites of Uranus [PDF]
Monthly Notices of the Royal Astronomical Society, 1870 A. Marth
openalex +4 more sources
Performance Assessment of Non-Integer-Hour Data Blocks in BDS Broadcast Ephemeris
IEEE AccessDue to system anomalies, BeiDou navigation satellite system (BDS) sometimes updates the broadcast ephemeris at non-integral hours. The gross errors contained in the non-integer-hour data blocks of broadcast ephemeris will lead to the signal-in-space (SIS)
Jingjing Wang, Chao Zhou
doaj +1 more source
Laser Terminals on CubeSats: Developments for Telecommunications and Quantum Links
International Journal of Satellite Communications and Networking, EarlyView.ABSTRACT Satellite‐based laser communication is an emerging technology that is finding its way from research to industry. Compared to radio frequency (RF) systems, it has a more efficient size, weight, and power budget and, furthermore, is license free.
Christian Roubal +8 more
wiley +1 more source