Publications (23)
Misleading variations in estimated rotational frequency splittings of solar p modes: Consequences for helio- and asteroseismology
Anne-Marie Broomhall, David Salabert, William J. Chaplin +4
The aim of this paper is to investigate whether there are any 11-yr or quasi-biennial solar cycle-related variations in solar rotational splitting frequencies of low-degree solar p…
The seismic diversity of four successive solar cycle minima as observed by the Birmingham Solar-Oscillations Network (BiSON)
Sarbani Basu, William J. Chaplin, Rachel Howe +3
We have used data collected by the Birmingham Solar-Oscillations Network (BiSON) to perform a helioseismic diagnosis of changes to the Sun's internal structure between four success…
Spatial incoherence of solar granulation: a global analysis using BiSON 2B data
Mikkel N. Lund, William J. Chaplin, Steven J. Hale +3
A poor understanding of the impact of convective turbulence in the outer layers of the Sun and Sun-like stars challenges the advance towards an improved understanding of their inte…
Solar Cycle Observations
Aimee Norton, Rachel Howe, Lisa Upton +1
We describe the defining observations of the solar cycle that provide constraints for the dynamo processes operating within the Sun. Specifically, we report on the following topics…
Asteroseismic constraints on active latitudes of solar-type stars: HD173701 has active bands at higher latitudes than the Sun
Alexandra E. L. Thomas, William J. Chaplin, Guy R. Davies +6
We present a new method for determining the location of active bands of latitude on solar-type stars, which uses stellar-cycle-induced frequency shifts of detectable solar-like osc…
Deciphering Solar Magnetic Activity I: On The Relationship Between The Sunspot Cycle And The Evolution Of Small Magnetic Features
Scott W. McIntosh, Xin Wang, Robert J. Leamon +6
Sunspots are a canonical marker of the Sun's internal magnetic field which flips polarity every ~22-years. The principal variation of sunspots, an ~11-year variation in number, mod…
Evidence of a Quasi-periodic Global-scale Oscillation in the Near-Surface Shear Layer of the Sun
Richard S. Bogart, Charles S. Baldner, Sarbani Basu +2
We present evidence of hitherto undiscovered global-scale oscillations in the near-surface shear layer of the Sun. These oscillations are seen as large scale variations of radial s…
Sensitivity of low-degree solar p modes to active and ephemeral regions: frequency shifts back to the Maunder Minimum
William J. Chaplin, Rachel Howe, Sarbani Basu +7
We explore the sensitivity of the frequencies of low-degree solar p-modes to near-surface magnetic flux on different spatial scales and strengths, specifically to active regions wi…
Solar Interior
Mark Linton, Mausumi Dikpati, Rachel Howe
This chapter introduces the reader to the solar interior, in particular the convection zone. The first section explores the solar cycle and the dynamo models that have been studied…
The QBO-type signals in the subsurface flow fields during solar cycles 23 and 24
Fadil Inceoglu, Rachel Howe, Paul T. M. Loto'aniu
We studied the presence and spatiotemporal evolution of the quasi-biennial oscillations (QBOs) in the rotation rate residuals at target depths of 0.90, 0.95,…
Unexpected solar-cycle variation of acoustic mode power in Sun-as-a-star observations
Rachel Howe, W. J. Chaplin, Y. P. Elsworth +2
We examine the solar-cycle variation of the power in the low-degree helioseismic modes by looking at binned power spectra from 45 years of observations with the Birmingham Solar Os…
Solar Interior Rotation and its Variation
Rachel Howe
This article surveys the development of observational understanding of the interior rotation of the Sun and its temporal variation over approximately forty years, starting with the…
Ensemble asteroseismology: An ensemble approach to detecting signatures of solar-like oscillations in K-dwarfs
William J. Chaplin, Tiago L. Campante, Mikkel N. Lund +5
Solar-like oscillations have to date been observed in hundreds of main-sequence and sub-giant stars. However, only a handful of detections have been made in K-type dwarfs, using gr…
Constraints on sunspot group lifetimes from far-side Sun-as-a-star helioseismology with BiSON
William J. Chaplin, Rachel Howe, Sarbani Basu +5
Frequencies of low-degree solar p modes are sensitive to activity over the entire Sun, including the unobservable far-side hemisphere. When frequency shifts extracted from week-lon…
Structure and Dynamics of the Sun's Interior Revealed by Helioseismic and Magnetic Imager
Alexander Kosovichev, Sarbani Basu, Yuto Bekki +43
High-resolution helioseismology observations with the Helioseismic and Magnetic Imager (HMI) onboard Solar Dynamics Observatory (SDO) provide a unique three-dimensional view of the…
Causal Interaction between the subsurface rotation rate residuals and radial magnetic field in different timescales
Fadil Inceoglu, Rachel Howe, Paul T. M. Loto'aniu
We studied the presence and spatiotemporal characteristics and evolution of the variations in the differential rotation rates and radial magnetic fields in the Schwabe and Quasi-bi…
Solar cycle variation of in helioseismic data and its implications for asteroseismology
Rachel Howe, William J. Chaplin, Sarbani Basu +7
The frequency, , at which the envelope of pulsation power peaks for solar-like oscillators is an important quantity in asteroseismology. We measure for…
Temporal Variations of High-Degree Solar p-Modes using Ring-Diagram Analysis
Olga Burtseva, Sushant Tripathy, Richard Bogart +4
We study temporal variations in the amplitudes and widths of high-degree acoustic modes by applying the ring-diagram technique to the GONG+, MDI and HMI Dopplergrams during the dec…
Sub-surface structural changes associated with successive 11-yr solar activity cycles have been progressively more confined near the surface: new helioseismic results on Cycles 22 -- 25 from BiSON
William J. Chaplin, Sarbani Basu, Rachel Howe +3
We use Sun-as-a-star helioseismology data, collected by the Birmingham Solar-Oscillations Network (BiSON), to examine the relationship between the solar-cycle-induced frequency shi…
Low-degree solar rotational splitting from 45 years of BiSON observations
Rachel Howe, W. J. Chaplin, Y. P. Elsworth +2
We present solar low-degree rotational splitting values based on a new analysis of Sun-as-a-star observations from the Birmingham Solar Oscillations Network, covering a 16,425-day…
Two-Dimensional Helioseismic Power, Phase, and Coherence Spectra of {\it Solar Dynamics Observatory} Photospheric and Chromospheric Observables
Rachel Howe, Kiran Jain, Richard S. Bogart +2
While the {\it Helioseismic and Magnetic Imager} (HMI) onboard the {\it Solar Dynamics Observatory} (SDO) provides Doppler velocity [], continuum intensity [], and line-dep…
Lifetimes and Rotation within the Solar Mean Magnetic Field
Eddie Ross, William J. Chaplin, Steven J. Hale +4
We have used very high-cadence (sub-minute) observations of the solar mean magnetic field (SMMF) from the Birmingham Solar Oscillations Network (BiSON) to investigate the morpholog…
Age dating of an early Milky Way merger via asteroseismology of the naked-eye star Indi
William J. Chaplin, Aldo M. Serenelli, Andrea Miglio +81
Over the course of its history, the Milky Way has ingested multiple smaller satellite galaxies. While these accreted stellar populations can be forensically identified as kinematic…