Search results
Results from the WOW.Com Content Network
Doppler spectroscopy (also known as the radial-velocity method, or colloquially, the wobble method) is an indirect method for finding extrasolar planets and brown dwarfs from radial-velocity measurements via observation of Doppler shifts in the spectrum of the planet's parent star. As of November 2022, about 19.5% of known extrasolar planets ...
In astronomy, minimum mass is the lower-bound calculated mass of observed objects such as planets, stars, binary systems, [1] nebulae, [2] and black holes.. Minimum mass is a widely cited statistic for extrasolar planets detected by the radial velocity method or Doppler spectroscopy, and is determined using the binary mass function.
Doppler imaging was first used to map chemical peculiarities on the surface of Ap stars.For mapping starspots it was first used by Steven Vogt and Donald Penrod in 1983, when they demonstrated that signatures of starspots were observable in the line profiles of the active binary star HR 1099 (V711 Tau); from this they could derive an image of the stellar surface.
While the radial velocity method provides information about a planet's mass, the photometric method can determine the planet's radius. If a planet crosses in front of its parent star's disk, then the observed visual brightness of the star drops by a small amount, depending on the relative sizes of the star and the planet. [6]
Two methods of recording may be used for this procedure. The first uses "B-mode" imaging, which displays a 2-dimensional image of the skull, brain, and blood vessels as seen by the ultrasound probe. Once the desired blood vessel is found, blood flow velocities may be measured with a pulsed Doppler effect probe
The Doppler parameter, or Doppler broadening parameter, usually denoted as , is a parameter commonly used in astrophysics to characterize the width of observed spectral lines of astronomical objects. It is defined as
International Olympic Committee (IOC) President Thomas Bach speaks at the opening of the executive board meeting of the IOC, at the Olympic House, in Lausanne, Switzerland, Tuesday, Dec. 3, 2024.
Pulse-Doppler signal processing begins with samples taken between multiple transmit pulses. Sample strategy expanded for one transmit pulse is shown. Pulse-Doppler begins with coherent pulses transmitted through an antenna or transducer. There is no modulation on the transmit pulse. Each pulse is a perfectly clean slice of a perfect coherent tone.