Publications (33)
Persistent Near-Surface Flow Structures from Local Helioseismology
R. Howe, R. W. Komm, D. Baker +3
Near-surface flows measured by the ring-diagram technique of local helioseismology show structures that persist over multiple rotations. We examine these phenomena using data from…
A Distant Mirror: Solar Oscillations Observed on Neptune by the Kepler K2 Mission
P. Gaulme, J. F. Rowe, T. R. Bedding +24
Starting in December 2014, Kepler K2 observed Neptune continuously for 49 days at a 1-minute cadence. The goals consisted of studying its atmospheric dynamics (Simon et al. 2016),…
Parametrizing the time-variation of the "surface term" of stellar p-mode frequencies: application to helioseismic data
R. Howe, S. Basu, G. R. Davies +4
The solar-cyle variation of acoustic mode frequencies has a frequency dependence related to the inverse mode inertia. The discrepancy between model predictions and measured oscilla…
The Sun's interior structure and dynamics, and the solar cycle
A. -M. Broomhall, P. Chatterjee, R. Howe +2
The Sun's internal structure and dynamics can be studied with helioseismology, which uses the Sun's natural acoustic oscillations to build up a profile of the solar interior. We di…
Atmospheric extinction coefficients in the band for several major international observatories: Results from the BiSON telescopes, 1984 to 2016
S. J. Hale, W. J. Chaplin, G. R. Davies +7
Over 30 years of solar data have been acquired by the Birmingham Solar Oscillations Network (BiSON), an international network of telescopes used to study oscillations of the Sun. F…
Local helioseismology of sunspot regions: comparison of ring-diagram and time-distance results
A. G. Kosovichev, S. Basu, R. Bogart +10
Local helioseismology provides unique information about the subsurface structure and dynamics of sunspots and active regions. However, because of complexity of sunspot regions loca…
Solar-cycle variation of the sound-speed asphericity from GONG and MDI data 1995-2000
H. M. Antia, S. Basu, F. Hill +3
We study the variation of the frequency splitting coefficients describing the solar asphericity in both GONG and MDI data, and use these data to investigate temporal sound-speed va…
Oscillation mode linewidths of main-sequence and subgiant stars observed by Kepler
T. Appourchaux, O. Benomar, M. Gruberbauer +20
Solar-like oscillations have been observed by {\it Kepler} and CoRoT in several solar-type stars. We study the variations of stellar p-mode linewidth as a function of effective tem…
Farside helioseismology with Sun-as-a-star data: the solar cycle as seen with 7-day-long BiSON timeseries
R. Howe, W. J. Chaplin, Y. P. Elsworth +3
We present results from fitting -mode spectra derived from 7-d segments of Sun-as-a-star helioseismic observations from the Birmingham Solar Oscillations Network covering 32 yr.…
Asteroseismology of the solar analogs 16 Cyg A & B from Kepler observations
T. S. Metcalfe, W. J. Chaplin, T. Appourchaux +34
The evolved solar-type stars 16 Cyg A & B have long been studied as solar analogs, yielding a glimpse into the future of our own Sun. The orbital period of the binary system is too…
Signatures of Solar Cycle 25 in Subsurface Zonal Flows
R. Howe, F. Hill, R. Komm +5
The pattern of migrating zonal flow bands associated with the solar cycle, known as the torsional oscillation, has been monitored with continuous global helioseismic observations b…
Properties of 42 Solar-type Kepler Targets from the Asteroseismic Modeling Portal
T. S. Metcalfe, O. L. Creevey, G. Dogan +39
Recently the number of main-sequence and subgiant stars exhibiting solar-like oscillations that are resolved into individual mode frequencies has increased dramatically. While only…
A note on the torsional oscillation at solar minimum
R. Howe, J. Christensen-Dalsgaard, F. Hill +3
We examine the evolution of the zonal flow pattern in the upper solar convection zone during the current extended solar minimum, and compare it with that during the previous minimu…
Performance of the Birmingham Solar-Oscillations Network (BiSON)
S. J. Hale, R. Howe, W. J. Chaplin +2
The Birmingham Solar-Oscillations Network (BiSON) has been operating with a full complement of six stations since 1992. Over 20 years later, we look back on the network history. Th…
Changes in the sensitivity of solar p-mode frequency shifts to activity over three solar cycles
R. Howe, W. J. Chaplin, G. R. Davies +3
Low-degree solar p-mode observations from the long-lived Birmingham Solar Oscillations Network (BiSON) stretch back further than any other single helioseismic data set. Results fro…
Subsurface Meridional Circulation in the Active Belts
I. Gonzalez Hernandez, S. Kholikov, F. Hill +2
Temporal variations of the subsurface meridional flow with the solar cycle have been reported by several authors. The measurements are typically averaged over periods of time durin…
The Sun in transition? Persistence of near-surface structural changes through Cycle 24
R. Howe, G. R. Davies, W. J. Chaplin +5
We examine the frequency shifts in low-degree helioseismic modes from the Birmingham Solar-Oscillations Network (BiSON) covering the period from 1985 - 2016, and compare them with…
Detector bandwidth and polarisation switching rates: spectrophotometric observations of the Sun by the Birmingham Solar Oscillations Network (BiSON)
S. J. Hale, W. J. Chaplin, G. R. Davies +2
The Birmingham Solar Oscillations Network (BiSON) observes acoustic oscillations of the Sun. The dominant noise source is caused by fluctuations of Earth's atmosphere, and BiSON se…
Signatures of magnetic activity in the seismic data of solar-type stars observed by Kepler
A. R. G. Santos, T. L. Campante, W. J. Chaplin +8
In the Sun, the frequencies of the acoustic modes are observed to vary in phase with the magnetic activity level. These frequency variations are expected to be common in solar-type…
Impact of low-frequency p modes on the inversions of the internal rotation of the Sun
D. Salabert, A. Eff-Darwich, R. Howe +1
We used the m-averaged spectrum technique ("collapsogram") to extract the low-frequency solar p-mode parameters of low- and intermediate-angular degrees (l \leq 35) in long time se…
What Solar Oscillation Tell us About the Solar Minimum
Kiran Jain, S. C. Tripathy, O. Burtseva +6
The availability of continuous helioseismic data for two consecutive solar minima has provided a unique opportunity to study the changes in the solar interior that might have led t…
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…
The next generation Birmingham Solar Oscillations Network (BiSON) spectrophotometer: a new miniaturised instrument for helioseismology
S. J. Hale, W. J. Chaplin, G. R. Davies +2
We describe a new spectrophotometer for the Birmingham Solar Oscillations Network (BiSON), based on a next generation observation platform, BiSON:NG, a significantly miniaturised s…
Seismic signatures of magnetic activity in solar-type stars observed by Kepler
A. R. G. Santos, T. L. Campante, W. J. Chaplin +8
The properties of the acoustic modes are sensitive to magnetic activity. The unprecedented long-term Kepler photometry, thus, allows stellar magnetic cycles to be studied through a…
Meridional Circulation During the Extended Solar Minimum: Another Component of the Torsional Oscillation?
I. Gonzalez Hernandez, R. Howe, R. Komm +1
We show here a component of the meridional circulation developing at medium-high latitudes (40-50 degrees) before the new solar cycle starts. Like the torsional oscillation of the…
A Revised Collection of Sunspot Group Numbers
J. M. Vaquero, L. Svalgaard, V. M. S. Carrasco +7
We describe a revised collection of the number of sunspot groups from 1610 to the present. This new collection is based on the work of Hoyt and Schatten (Solar Phys. 179, 189, 1998…
Validation of solar-cycle changes in low-degree helioseismic parameters from the Birmingham Solar-Oscillations Network
R. Howe, G. R. Davies, W. J. Chaplin +2
We present a new and up-to-date analysis of the solar low-degree -mode parameter shifts from the Birmingham Solar-Oscillations Network (BiSON) over the past 22 years, up to the…
Oscillation mode frequencies of 61 main sequence and subgiant stars observed by Kepler
T. Appourchaux, W. J. Chaplin, R. A. Garcia +25
Solar-like oscillations have been observed by Kepler and CoRoT in several solar-type stars, thereby providing a way to probe the stars using asteroseismology. We provide the mode f…
Temporal Variations of High-Degree Solar p-Modes from GONG and MDI
Olga Burtseva, S. C. Tripathy, R. Howe +4
We study temporal variations in the amplitudes and widths of high-degree acoustic modes in the quiet and active Sun by applying ring-diagram technique to the GONG+ and MDI Dopplerg…
Signatures of magnetic activity: On the relation between stellar properties and p-mode frequency variations
A. R. G. Santos, T. L. Campante, W. J. Chaplin +12
In the Sun, the properties of acoustic modes are sensitive to changes in the magnetic activity. In particular, mode frequencies are observed to increase with increasing activity le…
Kepler Observations of the Asteroseismic Binary HD 176465
T. R. White, O. Benomar, V. Silva Aguirre +31
Binary star systems are important for understanding stellar structure and evolution, and are especially useful when oscillations can be detected and analysed with asteroseismology.…
Oscillation mode linewidths and heights of 23 main-sequence stars observed by Kepler
T. Appourchaux, H. M. Antia, O. Benomar +9
Solar-like oscillations have been observed by Kepler and CoRoT in many solar-type stars, thereby providing a way to probe the stars using asteroseismology. We provide the mode line…
Deeply penetrating banded zonal flows in the solar convection zone
R. Howe, J. Christensen-Dalsgaard, F. Hill +5
Helioseismic observations have detected small temporal variations of the rotation rate below the solar surface corresponding to the so-called `torsional oscillations' known from Do…