Published contributions

Overview:

Over the years, I’ve been fortunate enough to work with a ton of great people on a variety of interesting problems. This has resulted in quite a few publications, and several more manuscripts in the pipeline!

Summary:

H-index: 25
2164 total citations (01/24/2025)
66 Publications ; 9 submitted / in review
12 first author (2 in review; 1 in prep.)
7 publications by students

Springer Thesis Prize:

In 2021, my PhD thesis was selected for the Springer Thesis prize and was published in the Springer Thesis series.

tbd 2025

Puffins: Flexible regression-based models for strictly periodic signals in time series data

Johnston C. , Hogg D.w., Eisner N.L. et al.

A&A, in prep.

This manuscript presents and discusses a regression-based model for modelling and predicting the time series behaviour of strictly periodic signals.

Keywords: time series analysis; regression; prediction

tbd 2025

Predicting the pulsation properties of massive stars with envelopes stripped via binary interaction: Adiabatic mode properties, pulsation patterns, and consequences for observations

Johnston C. , Gotberg Y., Townsend R.H.D. et al.

Astronomy & Astrophysics, in prep.

This manuscript presents the first calculations predicting the properties of pulsations in the exotic class of bianry evolution products known as stripped stars

Keywords: binary stars; stability analysis; asteroseismology

December 2024

Observational mapping of the mass discrepancy in eclipsing binaries

Serebriakova N., Tkachenko A., Johnston C. , et al.

Astronomy & Astrophysics, in review

Development and application of a global optimization algorithm for modelling the multiple time series of an eclipsing binary system to provide a consistent modelling methodology

Keywords: binary stars; optimization; time-series analysis

December 2024

Eclipsing binary systems with β Cephei components: V1216 Sco

Miszuda A., et al.

Astronomy & Astrophysics, in review , arXiv:2501.03770

Detailed binary, asteroseismic, and evolutionary modelling of a post-mass-transfer eclipsing binary with a pulsating component.

Keywords: binary stars; asteroseismology; time-series analysis

December 2024

Binarity at LOw Metallicity (BLOeM): IV: multiplicity of blue supergiants in the SMC

Britavsky N. et al.

Astronomy & Astrophysics, in review

The fourth installment of the BLOeM series investigating the time series properties of blue supergiants to determine their binarity fraction

Keywords: Statistics; binary stars; stellar evolution; time series analysis

January 2025

Planet formation and long-term stability in a very eccentric stellar binary

Stegmann J., Grichner E., Johnston C. , et al.

in review arXiv:2501.05506

This manuscript is a follow-up to Eisner et al., 2024 that investigates the stability of planets in s-type orbits in circumbinary planet systems using numerical simulations

Keywords: Numerical simulations; stability analysis; exoplanets

September 2024

Towards an improved stellar age determination through joint modeling of binarity and asteroseismology: Asteroseismic grid modeling of the seismic red-giant binary KIC 9163796

Grossman D. et al.

Astronomy & Astrophysics, accepted

This work builds upon the framework of Johnston et al., 2019b to simultaneously apply asteroseismic and binary information in evolutionary modelling

Keywords: Statistics; binary stars; stellar evolution; model optimization

September 2024

Variability of hot sub-luminous stars and binaries: Machine learning analysis of Gaia DR3 multi-epoch photometry

Ranaivomanana P., Uzundag M., Johnston C. et al.

Astronomy & Astrophysics, accepted arXiv:2411.18609

This work introduces, validates, and applies a novel machine learning framework for identifying variable stars based on their summary statistics

Keywords: Machine learning; random forest; dimensionality reduction; statistics

September 2024

Statistical view of orbital circularisation with 14,000 characterised TESS eclipsing binaries

IJspeert L.W., Tkachenko A., Johnston C. et al.

Astronomy & Astrophysics, Volume 691, id. A242, 17 pp.

Statistical analysis of the relationship between fundamental stellar parameters and tidal physics in close binaries

Keywords: Statistics; binary stars; tides

September 2024

BLOeM II: A high fraction of close massive binaries at low metallicity

Sana H. et al.

in review

Statistical analysis of a well characterised sample of close, massive binries in the SMC observed as a part of the BLOeM survey.

Keywords: Statistics; populations; binary stars; stellar evolution

September 2024

Red supergiants in young open clusters -- predictions based on detailed binary evolution models

Wang C. et al.

The Astrophysical Journal: Letters, submitted

Study investigating the impact of binary evolution on the rates and properties of red supergiants in clusters

Keywords: Photometry; clusters; binary stars; stellar evolution

September 2024

The BlackGEM telescope array I: overview

Groot P.J. et al.

Publications of the Astronomical Society of the Pacific, Issue 11, id.115003, 17 pp.

Introduction and description of the BlackGEM telescope array and its survey designs

Keywords: Photometry; time series; statistics; variability; instruments

September 2024

The secondary component of the extreme low mass ratio massive binary HD 165246 revealed by GHOST

Rodriguez C. et al.

Astronomy & Astrophysics, accepted

Updated analysis of the most massive EB+pulsating system HD 165246 using new high precision time series spectroscopic data that allows for the detection of the secondary component at a 1% light contribution.

Keywords: Pulsations; periodic signals; statistics; photometry; linear regression;

September 2024

Multi-colour amplitude ratios and phase differences for asteroseismology from combined ground and space-based telescopes

Johnston C. , Ranaivomanana P., Groot P.J. et al.

Astronomy & Astrophysics, in review

Introduction and application of a new regression based algorithm for determining the amplitudes of periodic signals in multiple data sets with different statistical properties.

Keywords: Pulsations; periodic signals; statistics; photometry; linear regression;

September 2024

Discerning internal conditions of pulsating hot subdwarf B stars: Modelling multiple trapped modes in KIC 10001893

Ghasemi H., Uzundag M., Johnston C. et al.

Astronomy & Astrophysics, submitted

Detailed modelling of the time-series behaviour of an individual star based on 4-years of data. This work also introduces a new summary statistic and demonstrates its modelling capacity.

Keywords: Pulsations; periodic signals; time series data; photometry; convection;

July 2024

Binarity at LOw Metallicity (BLOeM): I. a spectroscopic VLT monitoring survey of massive stars in the SMC

Shenar T. et al.

Astronomy & Astrophysics, Volume 690, id. A289, 22 pp.

Consortium paper detailing the BLOeM survey setup and initial results.

Keywords: Binary stars; statistics; spectroscopy

July 2024

The asteroseismic imprints of mass transfer. A case study of a binary mass-gainer in the SPB instability strip

Wagg T., Johnston C. , Bellinger E.P. et al.

Astronomy & Astrophysics, Volume 687, id. A222, 14 pp.

Publication that, for the first time, identifies and quantifies the asteroseismic imprints of mass transfer in stars that have gained mass. This project was led by T. Wagg as a PhD student participating in the 2023 Kavli Summer program in Astrophysics.

Keywords: Binary stars; statistics; spectroscopy

June 2024

FINKER: Frequency Identification through Nonparametric KErnel Regression in astronomical time series

Stoppa F., Johnston C. , Cator E. et al.

Astronomy & Astrophysics, Volume 686, A158

Summary: Development of a novel periodogram method that utilizes non-parametric kernel regression to identify periodicities in sparsely sampled time series data.

Keywords: methods: data analysis; methods: statistical; techniques: radial velocities; binaries: eclipsing; stars>

May 2024

Variability of Blue Supergiants in the LMC with TESS

Ma L., Johnston C. , Bellinger E.P. et al.

The Astrophysical Journal, Volume 966, 196

Summary: Publication that identifies and quantifies the behaviour of a stochastic signal in time series observations of Blue Super Giant stars.

Keywords: Stellar activity; Time series analysis; B supergiant stars

May 2024

Planet Hunters TESS. V. A Planetary System Around a Binary Star, Including a Mini-Neptune in the Habitable Zone

Eisner N.L. et al.

The Astronomical Journal, Volume 167, 241

Summary: Observational paper detailing the discovery of a rare S-type circumbinary planetary system found by the Planet Hunters TESS Citizen Science Project.

Keywords: Exoplanet systems; Exoplanet dynamics; Transit photometry; Binary stars; Habitable zone; Mini Neptunes; Radial velocity

May 2024

Automated eccentricity measurement from raw eclipsing binary light curves with intrinsic variability

IJspeert L.W., Tkachenko A., Johnston C. et al.

Astronomy & Astrophysics, Volume 685, A62

Summary: Development and application of an algorithm for analysing time series observations of eclipsing binary stars observed by the NASA TESS mission.

Keywords: asteroseismology; methods: data analysis; methods: statistical; ephemerides; binaries: eclipsing; Astrophysics - Instrumentation and Methods for Astrophysics

April 2024

Modelling Time-dependent Convective Penetration in 1D Stellar Evolution

Johnston C. , Michielsen M., Anders E.H. et al.

The Astrophysical Journal, Volume 964, 170

Summary: Development and presentation of a new algorithm for determining the extent of convective boundary mixing in stellar interiors, based on 3D hydrodynamical simulations.

Keywords: Stellar evolution; Stellar convective zones; Stellar structures; Stellar interiors

April 2023

Identifying and characterising the population of hot sub-luminous stars with multi-colour MeerLICHT data

Ranaivomanana P., Johnston C. , Groot P.J. et al.

Astronomy & Astrophysics, Volume 672, A69

Summary: Presenting a method for identifying and quantifying the time series variability of sdOB stars in multi-colour ground based photometry obtained by the MeerLICHT telescope in South Africa.

Keywords: surveys; subdwarfs; stars: variables: general; Hertzsprung-Russell and C-M diagrams; techniques: photometric; methods: data analysis; Statistics - Methodology

March 2023

Tidally perturbed gravity-mode pulsations in a sample of close eclipsing binaries

Van Reeth T., Johnston C. , Southworth J. et al.

Astronomy & Astrophysics, Volume 671, A121

Summary: Discovery and characterisation of g-mode pulsating stars in close binary systems with tidally influenced pulsations.

Keywords: asteroseismology; binaries: eclipsing; stars: oscillations; starspots; stars: rotation

February 2023

Tidal perturbations and eclipse mapping in the pulsations in the hierarchical triple system U Gru

Johnston C. , Tkachenko A., Van Reeth T. et al.

Astronomy & Astrophysics, Volume 670, A167

Summary: Detailed analysis of the time series behaviour of tidally modified pulsations in the close binary U Gru.

Keywords: asteroseismology; binaries: eclipsing; stars: individual: U Gru; stars: oscillations; binaries: close

August 2022

BlackGEM: the wide-field multi-band optical telescope array

Groot P.J. et al.

SPIE, Volume 12182, id. 121821V, 9 pp.

Summary: Description of the BlackGEM telescope array.

Keywords:

May 2022

SOAR/MeerLICHT classification of the Galactic plane transient AT2022jrn as a microlensing event

De K. et al.

The Astronomer's Telegram, Volume 15394, 1

Summary: Discovery of transient discovered by MeerLICHT.

Keywords: Microlensing Event; Transient

April 2022

Planet Hunters TESS IV: a massive, compact hierarchical triple star system TIC 470710327

Eisner N.L., Johnston C. , Toonen S. et al.

Monthly Notices of the Royal Astronomical Society, Volume 511, 4710-4723

Summary: Discovery and analysis of the most massive, compact triple system with a more massive tertiary companion known to date.

Keywords: binaries(including multiple): close; stars: individual: TIC 470710327; stars: massive

April 2022

Parameters of the eclipsing binary alpha Draconis observed by TESS and SONG

Hey D.R. et al.

Monthly Notices of the Royal Astronomical Society, Volume 511, 2648-2658

Summary: Detailed time series analysis of the eclipsing binary Alpha Draconis.

Keywords: binaries: eclipsing; stars: chemically peculiar; stars: fundamental parameters

January 2022

TESS Eclipsing Binary Stars. I. Short-cadence Observations of 4584 Eclipsing Binaries in Sectors 1-26

Prsa A. et al.

The Astrophysical Journals, Volume 258, 16

Summary: Catalogue paper for Eclipsing Binary stars observed by the TESS mission.

Keywords: Time series analysis; Binaries: close

November 2021

TESS Data for Asteroseismology (T'DA) Stellar Variability Classification Pipeline: Setup and Application to the Kepler Q9 Data

Audenaert J. et al.

The Astronomical Journal, Volume 162, 209

Summary: Paper detailing the development and application of a supervised classification algorithm for the time series variability of stars observed by the Kepler Mission.

Keywords: Asteroseismology; Machine learning; Classification

November 2021

One size does not fit all: Evidence for a range of mixing efficiencies in stellar evolution calculations

Johnston C.

Astronomy & Astrophysics, Volume 655, A29

Summary: Publication presenting evidence that no single published value for convective boundary mixing can explain the variety of observations from binary stars and asteroseismology.

Keywords: stars: evolution; stars: interiors; binaries: eclipsing; stars: oscillations; asteroseismology

August 2021

Rotational variation in the chemically peculiar B0 star \ensuremath\theta Car as seen by TESS

Koen C., Johnston C.

Monthly Notices of the Royal Astronomical Society, Volume 505, 5725-5730

Summary: Detailed time series analysis of a B0 star demonstrating that the signal likely originates from rotation and not binarity.

Keywords: stars: individual: HR 4199; stars: massive; stars: rotation

August 2021

An all-sky sample of intermediate- to high-mass OBA-type eclipsing binaries observed by TESS

IJspeert L.W., Tkachenko A., Johnston C. et al.

Astronomy & Astrophysics, Volume 652, A120

Summary: Development and application of a non-machine learning based algorithm that identifies eclipsing binary stars through their time series behaviour and derivatives thereof.

Keywords: asteroseismology; binaries: eclipsing; catalogs; ephemerides; stars: early-type; methods: data analysis;

May 2021

Characterization of the variability in the O+B eclipsing binary HD 165246

Johnston C. , Aimar N., Abdul-Masih M. et al.

Monthly Notices of the Royal Astronomical Society, Volume 503, 1124-1137

Summary: Detailed time series analysis of time series varibility of HD 165246, using MCMC and Fourier analysis to derive highly precise fundamental stellar parameters.

Keywords: asteroseismology; binaries: eclipsing; stars: individual: HD 165246; stars: massive; stars: oscillations

April 2021

Discovery and Characterization of a Rare Magnetic Hybrid \ensuremath\beta Cephei Slowly Pulsating B-type Star in an Eclipsing Binary in the Young Open Cluster NGC 6193

Stassun K.G., Torres G., Johnston C. et al.

The Astrophysical Journal, Volume 910, 133

Summary: Discovery and detailed time series analysis of a rare type of variable star in a binary with multiple types of variability.

Keywords: Beta Cephei variable stars; Double-mode variable stars; Eclipsing binary stars; Young star clusters; Pulsating variable stars

April 2021

A comparison of the dynamical and model-derived parameters of the pulsating eclipsing binary KIC 9850387

Sekaran S., Tkachenko A., Johnston C. et al.

Astronomy & Astrophysics, Volume 648, A91

Summary: High precision modelling of the time series data of KIC 9850387, demonstrating deficiencies in asteroseismic models.

Keywords: stars: individual: KIC 9850387; binaries: eclipsing; stars: oscillations; stars: fundamental parameters; stars: evolution; asteroseismology

March 2021

Planet Hunters TESS II: findings from the first two years of TESS

Eisner N.L. et al.

Monthly Notices of the Royal Astronomical Society, Volume 501, 4669-4690

Summary: Catalogue and method paper detailing the Planet Hunters TESS pipeline and results.

Keywords: methods: data analysis; catalogues; planets and satellites: detection; planets and satellites: general; planetary systems

January 2021

V772 Cas: an ellipsoidal HgMn star in an eclipsing binary

Kochukhov O., Johnston C. , Labadie-Bartz J. et al.

Monthly Notices of the Royal Astronomical Society, Volume 500, 2577-2589