36 citations · 139 across the 14 of their papers we have counts for
15 papers
The Curious Case of Dark Faculae on M Dwarf Stars
Alexander~I. ~Shapiro, Sara~Seager, Sami~K. ~Solanki +6
The study of exoplanet atmospheres has brought a renewed interest in stellar astrophysics. Specifically, stellar magnetic activity from the host star contaminates exoplanet atmosph…
Sensitivity of spectral lines to granulation: from the Sun to K-type stars
V. Vasilyev, K. Sowmya, A. I. Shapiro +7
Stellar granulation produces radial-velocity (RV) jitter at the 1 m/s level in Sun-like stars, limiting Earth-analog detection. A route beyond this limit is to weight spectral line…
Simulations of facular magnetic fields on cool stars I: Main sequence stars with solar metallicity
Tanayveer Singh Bhatia, Robert H. Cameron, Sami K. Solanki +4
Stellar convection in the presence of magnetic field affects the emergent intensity, as well as the structure and evolution of cool main-sequence dwarfs. We aim to understand the e…
3D Radiative MHD Simulations of Starspots II: Large-scale Structure
Tanayveer Singh Bhatia, Mayukh Panja, Robert Cameron +1
We compute realistic 3D radiative MHD near-surface models of starspots with substantial penumbrae on cool main-sequence stars using the MURaM simulation code. This work is an impro…
First Calculations of Starspot Spectra based on 3D Radiative Magnetohydrodynamics Simulations
H. N. Smitha, Alexander I. Shapiro, Veronika Witzke +6
Accurate calculations of starspot spectra are essential for multiple applications in astronomy. The current standard is to represent starspot spectra by spectra of stars that are c…
Small-scale Dynamo in Cool Stars III. Changes in the photospheres of F3V to M0V stars
Tanayveer S. Bhatia, Robert H. Cameron, Hardi Peter +1
Some of the quiet solar magnetic flux could be attributed to a small-scale dynamo (SSD) operating in the convection zone. An SSD operating in cool main-sequence stars is expected t…
Testing MURaM and MPS-ATLAS against the quiet solar spectrum
Veronika Witzke, Alexander I. Shapiro, Nadiia M. Kostogryz +8
Three-dimensional (3D) radiative magnetohydrodynamics (MHD) simulations are the only way to model stellar atmospheres without any ad hoc parameterisations. Several 3D radiative MHD…
Small-scale dynamos: From idealized models to solar and stellar applications
Matthias Rempel, Tanayveer Bhatia, Luis Bellot Rubio +1
In this article we review small-scale dynamo processes that are responsible for magnetic field generation on scales comparable to and smaller than the energy carrying scales of tur…
Small-scale dynamo in cool main sequence stars. II. The effect of metallicity
V. Witzke, H. B. Duehnen, A. I. Shapiro +4
All cool main sequence stars including our Sun are thought to have magnetic fields. Observations of the Sun revealed that even in quiet regions small-scale turbulent magnetic field…
Small-scale Dynamo in Cool Stars: I. Changes in stratification and near-surface convection for main-sequence spectral types
Tanayveer S. Bhatia, Robert H. Cameron, Sami K. Solanki +4
Some of the small-scale solar magnetic flux can be attributed to a small-scale dynamo (SSD) operating in the near-surface convection. The SSD fields have consequences for solar gra…
AR Sco as a possible seed of highly magnetised white dwarf
Banibrata Mukhopadhyay, A. R. Rao, Tanayveer Singh Bhatia
We explore the possibility that the recently discovered white dwarf pulsar AR Sco acquired its high spin and magnetic field due to repeated episodes of accretion and spin-down. An…
Significantly super-Chandrasekhar limiting mass white dwarfs and their consequences
Banibrata Mukhopadhyay, Upasana Das, A. R. Rao +5
Since 2012, we have initiated a new idea showing that the mass of highly magnetized or modified Einstein's gravity induced white dwarfs could be significantly super-Chandrasekhar w…
Exploring nonnormality in magnetohydrodynamic rotating shear flows: application to astrophysical accretion disks
Tanayveer Singh Bhatia, Banibrata Mukhopadhyay
The emergence of turbulence in shear flows is a well-investigated field. Yet, one of major issues is the apparent contradiction between linear stability analysis quoting a flow to…
Anti-symmetric square well and barrier potential between two rigid walls
Zafar Ahmed, Shashin Pavaskar, Indresh Yadav +1
We study an anti-symmetric (square) well and barrier potential of depth/height placed between two rigid walls. Unlike the usual double-well, here the closely lying sub-barr…
Special rectangular (double-well and hole) potentials
Zafar Ahmed, Tanayveer Bhatia, Shashin Pavaskar +1
We revisit a rectangular barrier as well as a rectangular well (pit) between two rigid walls. The former is the well known double-well potential and the latter is a hole potential.…