Publications (32)
Are low-degree p mode frequencies predictable from one cycle to the next?
A. M. Broomhall, W. J. Chaplin, Y. Elsworth +2
The Birmingham Solar-Oscillations Network (BiSON) has been collecting data for over 30yrs and so observations span nearly three 11yr solar activity cycles. This allows us to addres…
The inhomogeneous response across the solar disc of unresolved Doppler velocity observations
A. M. Broomhall, W. J. Chaplin, Y. Elsworth +1
Unresolved Doppler velocity measurements are not homogenous across the solar disc (Brookes et al. 1978). We consider one cause of the inhomogeneity that originates from the BiSON i…
A new efficient method for determining weighted power spectra: detection of low-frequency solar p-modes by analysis of BiSON data
S. T. Fletcher, A. -M. Broomhall, W. J. Chaplin +2
We present a new and highly efficient algorithm for computing a power spectrum made from evenly spaced data which combines the noise-reducing advantages of the weighted fit with th…
Definitive Sun-as-a-star p-mode frequencies: 23 years of BiSON observations
A-M. Broomhall, W. J. Chaplin, G. R. Davies +5
We present a list of "best possible" estimates of low-degree p-mode frequencies, from 8640 days of observations made by the Birmingham Solar-Oscillations Network (BiSON). This is t…
Sun-as-a-star observations: evidence for degree dependence of changes in damping of low-l p modes along the solar cycle
D. Salabert, W. J. Chaplin, Y. Elsworth +2
We use 9.5-yr of BiSON Sun-as-a-star data to search for dependence of solar-cycle parameter changes on the angular degree, l, of the data. The nature of the Sun-as-a-star observati…
A precise asteroseismic age and radius for the evolved Sun-like star KIC 11026764
T. S. Metcalfe, M. J. P. F. G. Monteiro, M. J. Thompson +55
The primary science goal of the Kepler Mission is to provide a census of exoplanets in the solar neighborhood, including the identification and characterization of habitable Earth-…
Radius determination of solar-type stars using asteroseismology: What to expect from the Kepler mission
D. Stello, W. J. Chaplin, H. Bruntt +22
For distant stars, as observed by the NASA Kepler satellite, parallax information is currently of fairly low quality and is not complete. This limits the precision with which the a…
A comparison of frequentist and Bayesian inference: Searching for low-frequency p modes and g modes in Sun-as-a-star data
A. -M. Broomhall, W. J. Chaplin, Y. Elsworth +2
We describe and use two different statistical approaches to try and detect low-frequency solar oscillations in Sun-as-a-star data: a frequentist approach and a Bayesian approach. W…
Solar internal sound speed as inferred from combined BiSON and LOWL oscillation frequencies
Sarbani Basu, W. J. Chaplin, J. Christensen-Dalsgaard +6
Observations of the Sun with the LOWL instrument provide a homogeneous set of solar p-mode frequencies from low to intermediate degree which allows one to determine the structure o…
Excitation and damping of p-mode oscillations of alpha Cen B
W. J. Chaplin, G. Houdek, Y. Elsworth +3
This paper presents an analysis of observational data on the p-mode spectrum of the star alpha Cen B and a comparison with theoretical computations of the stochastic excitation and…
The Octave (Birmingham - Sheffield Hallam) automated pipeline for extracting oscillation parameters of solar-like main-sequence stars
S. Hekker, A. -M Broomhall, W. J. Chaplin +6
The number of main-sequence stars for which we can observe solar-like oscillations is expected to increase considerably with the short-cadence high-precision photometric observatio…
Is the current lack of solar activity only skin deep?
A. -M. Broomhall, W. J. Chaplin, Y. Elsworth +2
The Sun is a variable star whose magnetic activity and total irradiance vary on a timescale of approximately 11 years. The current activity minimum has attracted considerable inter…
The solar core: new low-l p-mode fine-spacing results from BiSON
W. J. Chaplin, Y. Elsworth, G. R. Isaak +3
The fine-structure spacing for low-degree solar p modes of angular degree and radial order n, is sensitive to conditions in the…
Predicting the detectability of oscillations in solar-type stars observed by Kepler
W. J. Chaplin, H. Kjeldsen, T. R. Bedding +49
Asteroseismology of solar-type stars has an important part to play in the exoplanet program of the NASA Kepler Mission. Precise and accurate inferences on the stellar properties th…
Challenges for asteroseismic analysis of Sun-like stars
W. J. Chaplin, G. Houdek, T. Appourchaux +3
Asteroseismology of Sun-like stars is undergoing rapid expansion with, for example, new data from the CoRoT mission and continuation of ground-based campaigns. There is also the ex…
Evidence for the impact of stellar activity on the detectability of solar-like oscillations observed by Kepler
W. J. Chaplin, T. R. Bedding, A. Bonanno +37
We use photometric observations of solar-type stars, made by the NASA Kepler Mission, to conduct a statistical study of the impact of stellar surface activity on the detectability…
Global asteroseismic properties of solar-like oscillations observed by Kepler : A comparison of complementary analysis methods
G. A. Verner, Y. Elsworth, W. J. Chaplin +24
We present the asteroseismic analysis of 1948 F-, G- and K-type main-sequence and subgiant stars observed by the NASA {\em Kepler Mission}. We detect and characterise solar-like os…
Distortion of the p-mode peak profiles by the solar-cycle frequency shifts: do we need to worry?
W. J. Chaplin, Y. Elsworth, R. New +1
We seek to address whether solar-cycle frequency shifts of the Sun's low-l p modes `distort' the underlying shapes of the mode peaks, when those peaks are observed in power frequen…
Corrections of Sun-as-a-star p-mode frequencies for effects of the solar cycle
A. -M. Broomhall, W. J. Chaplin, Y. Elsworth +2
Solar p-mode frequencies vary with solar activity. It is important to take this into account when comparing the frequencies observed from epochs that span different regions of the…
The asteroseismic potential of Kepler: first results for solar-type stars
W. J. Chaplin, T. Appourchaux, Y. Elsworth +105
We present preliminary asteroseismic results from Kepler on three G-type stars. The observations, made at one-minute cadence during the first 33.5d of science operations, reveal hi…
A modified peak-bagging technique for fitting low- solar p-modes
S. T. Fletcher, W. J. Chaplin, Y. Elsworth +1
We introduce a modified version of a standard power spectrum `peak-bagging' technique which is designed to gain some of the advantages that fitting the entire low-degree p-mode pow…
New aspects of Doppler imaging in Sun-as-a-star observations
A. M. Broomhall, W. J. Chaplin, Y. Elsworth +1
Birmingham Solar Oscillations Network (BiSON) instruments use resonant scattering spectrometers to make unresolved Doppler velocity observations of the Sun. Unresolved measurements…
Pseudo-global Fitting of Gapped Helioseismic Data
S. T. Fletcher, W. J. Chaplin, Y. Elsworth +1
Mode fitting or "peak-bagging" is an important procedure in helioseismology allowing one to determine the various mode parameters of solar oscillations. We have recently developed…
Ensemble Asteroseismology of Solar-Type Stars with the NASA Kepler Mission
W. J. Chaplin, H. Kjeldsen, J. Christensen-Dalsgaard +56
In addition to its search for extra-solar planets, the NASA Kepler Mission provides exquisite data on stellar oscillations. We report the detections of oscillations in 500 solartyp…
solarFLAG hare and hounds: estimation of p-mode frequencies from Sun-as-star helioseismology data
S. J. Jimenez-Reyes, W. J. Chaplin, R. A. Garcia +14
We report on the results of the latest solarFLAG hare-and-hounds exercise, which was concerned with testing methods for extraction of frequencies of low-degree solar p modes from d…
The simulation of realistic BiSON-like helioseismic data
S. T. Fletcher, R. New, W. J. Chaplin +1
When simulating full-disc helioseismic data, instrumental noise has traditionally been treated as time-independent. However, in reality, instrumental noise will often vary to some…
Solar cycle variations of large frequency separations of acoustic modes: Implications for asteroseismology
A. -M. Broomhall, W. J. Chaplin, Y. Elsworth +1
We have studied solar cycle changes in the large frequency separations that can be observed in Birmingham Solar Oscillations Network (BiSON) data. The large frequency separation is…
A devil in the detail: parameter cross-talk from the solar cycle and estimation of solar p-mode frequencies
W. J. Chaplin, S. J. Jimenez-Reyes, A. Eff-Darwich +2
Frequencies, powers and damping rates of the solar p modes are all observed to vary over the 11-yr solar activity cycle. Here, we show that simultaneous variations of these paramet…
Mode lifetimes of stellar oscillations - Implications for asteroseismology
W. J. Chaplin, G. Houdek, C. Karoff +2
Successful inference from asteroseismology relies on at least two things: that the oscillations in the stars have amplitudes large enough to be clearly observable; and that the osc…
Efficient pseudo-global fitting for helioseismic data
S. T. Fletcher, W. J. Chaplin, Y. Elsworth +1
Mode fitting or "peak-bagging" is an important procedure in helioseismology allowing one to determine the various mode parameters of solar oscillations. Here we describe a way of r…
solarFLAG hare and hounds: on the extraction of rotational p-mode splittings from seismic, Sun-as-a-star data
W. J. Chaplin, T. Appourchaux, F. Baudin +18
We report on results from the first solar Fitting at Low-Angular degree Group (solar FLAG) hare-and-hounds exercise. The group is concerned with the development of methods for extr…
AsteroFLAG: first results from hare-and-hounds Exercise 1
W. J. Chaplin, T. Appourchaux, T. Arentoft +15
We report on initial results from the first phase of Exercise 1 of the asteroFLAG hare and hounds. The asteroFLAG group is helping to prepare for the asteroseismology component of…