We first generate a stellar field with planetary companions based
on radial velocity discoveries, use a planetary evolution model assuming a variable fraction of heavy elements to compute the characteristics of transit events, then apply a detection criterion that includes both statistical and red noise sources.
It appears to be a main sequence red dwarf star of spectral and luminosity type M4.5 V. Because of its small mass and great distance from the primary (Star A), Upsilon Andromedae B appears to have a negligible effect
on the radial velocity measurements used to determine that Star A has at least three large planets (Lowrance et al, 2002).
Not exact matches
[1] The team used data from the UVES spectrograph
on ESO's Very Large Telescope in Chile (to determine the properties of the star accurately), the Carnegie Planet Finder Spectrograph (PFS) at the 6.5 - metre Magellan II Telescope at the Las Campanas Observatory in Chile, the HIRES spectrograph mounted
on the Keck 10 - metre telescope
on Mauna Kea, Hawaii as well as extensive previous data from HARPS (the High Accuracy
Radial velocity Planet Searcher) at ESO's 3.6 - metre telescope in Chile (gathered through the M dwarf programme led by X. Bonfils and M. Mayor 2003 - 2010.
Instead of becoming an Earth - shattering revelation, serious doubts were cast
on the detection, which also used
radial velocity.
They then calculated the size, position and mass of K2 - 229b by measuring the
radial velocity of the star, and finding out how much the starlight «wobbles» during orbit, due to the gravitational tug from the planet, which changes depending
on the planet's size.
«We designed an experiment to confirm what we suspected was there,» says team leader Guillem Anglada - Escudé of Queen Mary University of London, who used the European Southern Observatory's High Accuracy
Radial velocity Planet Searcher (HARPS) spectrograph
on a 3.6 - meter telescope in Chile.
Laughlin is a Co-I
on the Lick Carnegie Exoplanet Survey, and along with team members Steve Vogt, Paul Butler, Eugenio Rivera and Stefano Meschiari, is using the Keck, Magellan and AAT telescopes to discover and characterize planets with the Doppler
radial velocity technique.
Using the High Accuracy
Radial Velocity Planet Searcher, or HARPS, at the European Southern Observatory in Chile, his team measured the planet's gravitational influence
on its parent star.
Found via
radial velocity variations, the planet's true mass could not be known with knowing whether its orbit around Star B is being viewed edge -
on, face -
on, or somewhere in between.
On October 16, 2012, a team of astronomers announced the discovery of a planet with around 1.13 + / - 0.09 Earth - masses in a very hot and tight, circular orbit around Alpha Centauri B, using the European Southern Observatory's the High Accuracy Radial velocity Planet Searcher (HARPS) instrument on the 3.6 - metre telescope at ESO's La Silla Observatory in Chil
On October 16, 2012, a team of astronomers announced the discovery of a planet with around 1.13 + / - 0.09 Earth - masses in a very hot and tight, circular orbit around Alpha Centauri B, using the European Southern Observatory's the High Accuracy
Radial velocity Planet Searcher (HARPS) instrument
on the 3.6 - metre telescope at ESO's La Silla Observatory in Chil
on the 3.6 - metre telescope at ESO's La Silla Observatory in Chile.
On October 16, 2012, a team of astronomers announced the discovery of a planet with around 1.13 + / - 0.09 Earth - masses in a very hot and tight, circular orbit around Alpha Centauri B, using the European Southern Observatory's High Accuracy Radial velocity Planet Searcher (HARPS) instrument on the 3.6 - metre telescope at ESO's La Silla Observatory in Chil
On October 16, 2012, a team of astronomers announced the discovery of a planet with around 1.13 + / - 0.09 Earth - masses in a very hot and tight, circular orbit around Alpha Centauri B, using the European Southern Observatory's High Accuracy
Radial velocity Planet Searcher (HARPS) instrument
on the 3.6 - metre telescope at ESO's La Silla Observatory in Chil
on the 3.6 - metre telescope at ESO's La Silla Observatory in Chile.
Mikayla Mace introduced the most popular methods —
radial velocity, transit, and direct imaging — in an earlier post
on this blog.
Measurements of Gl 105A's
radial velocity over 12 years show a linear trend and slope which is consistent with these orbital constraints and a nearly face -
on orbit.
Based
on 14 years of
radial velocity observations from four ground - based observatories as well as astrometric measurements with the Hubble Space Telescope, the astronomers found that planets «c» and «d» are inclined by 30 + / - 1 degrees with respect to each other is expected to affect theories of how multi-planet systems evolve.
A subsequent analysis using the most recent kinematic and
radial velocity data available in the literature, however, found Proxima «is quitely likely» to be bound to to Stars A and B based
on calculations of the binding energy of Proxima relative to the center of mass of the entire triple system, where its orbital semi-major axis exceeds 10,000 AUs and is «
on order the same size as Alpha Centauri AB's Hill radius in the galactic potential» (Wertheimer and Laughlin, 2006).
Based
on astrometic as well as high - cadence
radial velocity measurements, planetary candidate «c» appears to have around 14.0 +2.3 / -5.3 times the mass of Jupiter (McArthur et al, 2010).
Radial velocity spectroscopy using the Double - Beam Spectrograph
on the Palomar 200 - inch indicates that the pulsar is massive: 1.74 ± 0.18 solar masses.
On March 25, 2015, a team of astronomers using the Hubble Space Telescope revealed observations which indicate via the transit method that Alpha Centauri B may have a second planet «c» in a hot inner orbit, just outside planet candidate «b.» After observing Alpha Centauri B in 2013 and 2014 for a total of 40 hours, the team failed to detect any transits involving planet b (previously detected using the radial velocity variations method and recently determined not to be observed edge - on in a transit orbit around Star B
On March 25, 2015, a team of astronomers using the Hubble Space Telescope revealed observations which indicate via the transit method that Alpha Centauri B may have a second planet «c» in a hot inner orbit, just outside planet candidate «b.» After observing Alpha Centauri B in 2013 and 2014 for a total of 40 hours, the team failed to detect any transits involving planet b (previously detected using the
radial velocity variations method and recently determined not to be observed edge -
on in a transit orbit around Star B
on in a transit orbit around Star B).
The new
radial velocity measurements are now available for download
on our website.
Based
on 86
radial velocity observations obtained with the HARPS - N spectrograph
on the Telescopio Nazionale Galileo and 32 archival Keck / HIRES observations, we present a prec... ▽ More Kepler - 93b is a 1.478 + / - 0.019 Earth radius planet with a 4.7 day period around a bright (V = 10.2), astroseismically - characterized host star with a mass of 0.911 + / -0.033 solar masses and a radius of 0.919 + / -0.011 solar radii.
Older calculations indicating that the Wolf 424 system would get as close to the Solar System as 0.95 light - years within around 7,500 years have been determined to be based
on a «probably erroneous»
radial velocity measurement (Vadim V. Bobylev, 2010; and Mülläri and Orlov, 1996).
We then measured the planet mass by acquiring twelve
radial velocity (RV) measurements of the system using HIRES
on the 10 - m Keck I Telescope.
On November 1, 2010, a team of astronomers working with the NASA - UC Eta - Earth Survey revealed the detection of a super-Earth in a torch orbit with a minimum of 8.2 + - 1.2 Earth - masses around BD +26 2184, using
radial -
velocity measures from the Keck Observatory's High Resolution Echelle Spectrometer (HIRES).
Planets «b, c, and d» -
On December 14, 2009, a team of astronomers (Steven S. Vogt; Robert A. Wittenmyer, R. Paul Butler, Simon O'Toole, Gregory W. Henry, Eugenio J. Rivera, Stefano Meschiari, Gregory Laughlin, C. G. Tinney, Hugh R. A. Jones, Jeremy Bailey, Brad D. Carter, and Konstantin Batygin) announced the discovery of one innermost orbiting super-Earth and two outer - orbiting, Neptune - class planets (with at least 5.1, 18.2, and 24.0 Earth - masses, respectively) in moderately circular, inner orbits around 61 Virginis with periods of 4.2, 38.0, and 124.0 days, based on radial - velocity observations over 4.6 years with the Keck Observatory's High Resolution Echelle Spectrometer (HIRES) and the Anglo - Australian Telescope (U.C. Santa Cruz news release; AAO press release; Keck press release; the Lick - Carnegie Exoplanet Survey Team's «Systemic Console;» and Vogt et al, 2009
On December 14, 2009, a team of astronomers (Steven S. Vogt; Robert A. Wittenmyer, R. Paul Butler, Simon O'Toole, Gregory W. Henry, Eugenio J. Rivera, Stefano Meschiari, Gregory Laughlin, C. G. Tinney, Hugh R. A. Jones, Jeremy Bailey, Brad D. Carter, and Konstantin Batygin) announced the discovery of one innermost orbiting super-Earth and two outer - orbiting, Neptune - class planets (with at least 5.1, 18.2, and 24.0 Earth - masses, respectively) in moderately circular, inner orbits around 61 Virginis with periods of 4.2, 38.0, and 124.0 days, based
on radial - velocity observations over 4.6 years with the Keck Observatory's High Resolution Echelle Spectrometer (HIRES) and the Anglo - Australian Telescope (U.C. Santa Cruz news release; AAO press release; Keck press release; the Lick - Carnegie Exoplanet Survey Team's «Systemic Console;» and Vogt et al, 2009
on radial -
velocity observations over 4.6 years with the Keck Observatory's High Resolution Echelle Spectrometer (HIRES) and the Anglo - Australian Telescope (U.C. Santa Cruz news release; AAO press release; Keck press release; the Lick - Carnegie Exoplanet Survey Team's «Systemic Console;» and Vogt et al, 2009).
From multi-epoch
radial velocities, we determine the masses of Kepler - 20b and Kepler - 20c to be 8.7 \ + -2.2 Mearth and 16.1 + -3.5 Mearth, respectively, and we place an upper limit
on the mass of Kepler - 20d of 20.1 Mearth (2 sigma).
Confirming that an exoplanet is real typically relies
on measuring the planet's mass, using a technique known as «
radial velocity».
Based
on radial -
velocity observations through 2009, no substellar companions were detected around Gl 433's habitable zone down to within a few Earth - masses (Zechmeister et al, 2009).
When we first embarked
on this project we were told unequivocally that precision
radial velocity measurements were impossible at the amateur level and required the funding and resources of an institution.
HD 211847's substellar companion, previously detected by the
radial velocity method, is actually a low - mass star seen face -
on.
Zeta1 has a brighter but distant stellar companion, Zeta2 Reticuli, currently located around 3,750 AUs away (based
on an observed separation of 310» and HIPPARCOS distance estimates of 39.40 to 39.53 ly), with common proper motion and equal
radial velocities (Da Silva and Foy, 1987).
Based
on knowing these common proper motions and
radial velocities, Alpha Centauri will continue to gradually brighten, passing just north of the Southern Cross or Crux, before moving northwest and up towards the present celestial equator and away from the galactic plane.
[106] Theoretical studies
on the detectability via
radial velocity analysis have shown that a dedicated campaign of high - cadence observations with a 1 - meter class telescope can reliably detect a hypothetical planet of 1.8 M ⊕ in the habitable zone of B within three years.
Furthermore, by knowing the mass of a planet from
radial velocity measurements and the radius of a planet based
on how much starlight it blocked, it is a simple calculation to determine a planet's density, which can tell astronomers whether that planet is rocky or gaseous in nature, or whether it has a small core and a thick atmosphere, or whether it has a large core covered in deep oceans.
This is
radial velocity work based on data gathered by the HARPS (High Accuracy Radial Velocity Planetary Searcher) spectrometer on the 3.6 - meter telescope at the European Southern Observatory in La Silla,
radial velocity work based on data gathered by the HARPS (High Accuracy Radial Velocity Planetary Searcher) spectrometer on the 3.6 - meter telescope at the European Southern Observatory in La Silla
velocity work based
on data gathered by the HARPS (High Accuracy
Radial Velocity Planetary Searcher) spectrometer on the 3.6 - meter telescope at the European Southern Observatory in La Silla,
Radial Velocity Planetary Searcher) spectrometer on the 3.6 - meter telescope at the European Southern Observatory in La Silla
Velocity Planetary Searcher) spectrometer
on the 3.6 - meter telescope at the European Southern Observatory in La Silla, Chile.
On January 7, 2002, astronomers announced the discovery of a brown dwarf companion to this Sol - type star using direct imaging (see press release and graphics), whose mass and orbit were subsequently refined with 24 years of
radial -
velocity observations — Crepp et al, 2012, with more details below).
Follow - up
radial velocity measurements with the Keck HIRES spectrograph
on 9 separate nights demonstrate that the planet is more than twice as massive as Jupiter with a mass of 2.114 + / -0.057 and a mean density of 0.894 + / -0.079 g / cm ^ 3.
(Many exoplanets have also been discovered using another technique called the
radial velocity method, which looks for the gravitational influence of a planet
on its star.)
The final validation of the planet is provided by 16
radial velocities obtained with HIRES
on Keck 1 over a one year span.
Subsequently, Heintz (1996, page 411) suggested that such a companion to Star Ba would have to have a mass of at least half Sol's to reach detectable brightness, and that, among other orbital requirements, Bc's period would have to be less than an Earth year in order to account for the absence of effects
on Ba's
radial velocities and positions.
Using multi-epoch optical and near - IR follow - up spectroscopy with FLAMES
on the Very Large Telescope and ISIS
on the William Herschel Telescope we obtain a full orbital solution and derive the fundamental parameters of both stars by modelling the light curve and
radial velocity data.
In addition, Tau Ceti does not appear to have a close stellar or substellar companion based
on astrometric measurements (Lippincott and Worth, 1980),
radial velocity variations (Campbell et al, 1988; and near - infrared interferometry (Di Folco et al, 2007).
In 2012, astronomers announced they'd found evidence for five planets between two and seven times the mass of the Earth, using the so - called
radial velocity or «wobble» method, which measures the gravitational tug a planet exerts
on its star.
On August 29, 2012, the Planetary Habitability Laboratory (PHL) revealed that a team of astronomers working with the High Accuracy
Radial velocity Planet Search (HARPS) project had discovered two planets «b» and «c» around the red dwarf star Gliese 163.
On March 4, 2014, a team of astronomers announced that analysis of new and older
radial -
velocity data from nearby red dwarf stars revealed two super-Earths «b» and «c» with minimum earth - masses of 4.4 (+3.7 / -2.4) and 8.7 (+5.8 / -4.7), respectively, at average orbital distances of 0.080 (+0.014 / -0.004) and 0.176 (+0.009 / -0.030) AU, respectively, from host star Gl 682, with orbital eccentricities of 0.08 (+0.19 / -.08) and 0.010 (+0.19 / -0.10) and periods around 17.5 and 57.3 days, respectively (UH news release; and Tuomi et al, 2014).
On March 4, 2014, a team of astronomers announced that analysis of new and older
radial -
velocity data from nearby red dwarf stars revealed two super-Earths «b» and «c.» Planet b has around 4.4 (+3.7 / -2.4) Earth - masses and an average orbital distance of 0.080 (+0.014 / -0.004) AU from host star Gl 682.
HARPS has been enormously successful at detecting exoplanets using the
radial velocity method, or measuring the gravitational tugs
on stars by their planets by watching the stars» spectral lines «wobble» back and forth due to the Doppler effect.
Based
on the drift of residual
radial velocities, moreover, there may be a fourth sub-stellar object in the system (Mayor et al, 2008).
The Geneva team used data from HARPS, or the High Accuracy
Radial Velocity for Planetary Searcher, a powerful spectrometer
on a 3.6 - meter telescope in Chile.
In June 2003, a team of astronomers (including Dominique Naef, Francisco Pepe, Michel Mayor, Nuno C. Santos, Didier Queloz, and Stephane Udry) announced the discovery of a Jupiter - class planet around HR 111232 using
radial -
velocity methods (Observatoire de Genève page
on HD 111232).
We report
on the results from the
radial -
velocity follow - up program performed to establish the planetary nature and to characterize the transiting candidates discovered by the space mission CoRoT.