Results 81 to 90 of about 2,481,024 (387)

Theoretical and Experimental Study of Radial Velocity Generation for Extending Bandwidth of Magnetohydrodynamic Angular Rate Sensor at Low Frequency

Sensors, 2015
The magnetohydrodynamics angular rate sensor (MHD ARS) has received much attention for its ultra-low noise in ultra-broad bandwidth and its impact resistance in harsh environments; however, its poor performance at low frequency hinders its work in long ...
Yue Ji, Xingfei Li, Tengfei Wu, Cheng Chen   +3 more
doaj   +1 more source

Simulations for Planning Next-generation Exoplanet Radial Velocity Surveys

The Astronomical Journal, 2023
Future direct imaging missions similar to the HabEx and LUVOIR mission concepts aim to catalog and characterize Earth-mass analogs around nearby stars.
Patrick D Newman, Peter Plavchan, Jennifer A. Burt, Johanna Teske, Eric E. Mamajek, Stephanie Leifer, B. Scott Gaudi, Gary Blackwood, Rhonda Morgan   +8 more
doaj   +1 more source

Radial Velocity Fitting Challenge. I. Simulating the data set including realistic stellar radial-velocity signals [PDF]

, 2016
Stellar signals are the main limitation for precise radial-velocity (RV) measurements. These signals arise from the photosphere of the stars. The m/s perturbation created by these signals prevents the detection and mass characterization of small-mass ...
X. Dumusque, X. Dumusque
semanticscholar   +1 more source

Commission 30: Radial Velocities: (Vitesses Radiales) [PDF]

Transactions of the International Astronomical Union, 2000
Commission 30 has 120 members in 28 countries who are active in the area of radial velocities. During the past triennium 11 new members have joined the commission. The work of the commission covers a wide range of topics all of which concern the application of the Doppler effect to astronomical objects, including galaxies and the interstellar medium as
Nidia Morrell, Francis C. Fekel, R.P. Stefanik, Stéphane Udry, Birgitta Nordström, Andrei Tokovinin, J.B. Hearnshaw, H. Quintana, W.D. Cochran, T. Mazeh   +9 more
openaire   +3 more sources

A Python package for fast GPU‐based proton pencil beam dose calculation

Journal of Applied Clinical Medical Physics, EarlyView.
Abstract Purpose Open‐source GPU‐based Monte Carlo (MC) proton dose calculation algorithms provide high speed and unparalleled accuracy but can be complex to integrate with new applications and remain slower than GPU‐based pencil beam (PB) methods, which sacrifice some physical accuracy for sub‐second plan calculation.
Mahasweta Bhattacharya, Calin Reamy, Heng Li, Junghoon Lee, William T. Hrinivich   +4 more
wiley   +1 more source

A RELATION BETWEEN DISTANCE AND RADIAL VELOCITY AMONG EXTRA-GALACTIC NEBULAE.

Proceedings of the National Academy of Sciences of the United States of America, 1929
Determinations of the motion of the sun with respect to the extra-galactic nebulae have involved a K term of several hundred kilometers which appears to be variable.
E. Hubble
semanticscholar   +1 more source

RADIAL VELOCITY MONITORING OF KEPLER HEARTBEAT STARS [PDF]

, 2016
Heartbeat stars (HB stars) are a class of eccentric binary stars with close periastron passages. The characteristic photometric HB signal evident in their light curves is produced by a combination of tidal distortion, heating, and Doppler boosting near ...
Avi Shporer, J. Fuller, H. Isaacson, K. Hambleton, S. Thompson, A. Prša, D. Kurtz, A. Howard, Ryan M. O'Leary   +8 more
semanticscholar   +1 more source

Radial velocity signatures of Zeeman broadening [PDF]

Astronomy & Astrophysics, 2013
Stellar activity signatures such as spots and plage can significantly limit the search for extrasolar planets. Current models of activity-induced radial velocity (RV) signals focused on the impact of temperature contrast in spots predicting the signal to diminish toward longer wavelengths. On the other hand, the relative importance of the Zeeman effect
Reiners, Ansgar, Shulyak, D., Anglada-Escude, Guillem, Jeffers, Sandra V., Morin, Julien, Zechmeister, Mathias, Kochukhov, Oleg, Piskunov, Nikolai E.   +7 more
openaire   +6 more sources

Searching for Planets in the Hyades V: Limits on Planet Detection in the Presence of Stellar Activity

, 2004
We present the results of a radial velocity survey of a sample of Hyades stars, and discuss the effects of stellar activity on radial velocity measurements. The level of radial velocity scatter due to rotational modulation of stellar surface features for
Allende Prieto C., Artie P. Hatzes, Diane B. Paulson, Kurster M., Vogt S. S., William D. Cochran   +5 more
core   +2 more sources

Evaluation of internal target volume of abdominal tumors using cine‐MRI

Journal of Applied Clinical Medical Physics, EarlyView.
Abstract Introduction The detailed anatomy visualization with magnetic resonance (MR)‐guided radiotherapy is particularly attractive for abdominal treatments, but patient respiratory motion can compromise image quality. The “navigator technique” produces high‐quality 3D images, triggered by diaphragm displacement, in exhale phase only.
Jessica Lye, Reza Alinaghi‐Zadeh, Sandie Fisher, Nikki Shelton, Glenn Cahoon, Leah McDermott, Richard Khor, Kym Rykers, Sweet Ping Ng   +8 more
wiley   +1 more source