Journal Publications


2021

Establishing α Oph as a Prototype Rotator: Precision Orbit with new Keck, CHARA, and RV Observations
Tyler Gardner, John D. Monnier, Francis C. Fekel, Michael Williamson, Fabien Baron, Sasha Hinkley, Michael Ireland, Adam L. Kraus, Stefan Kraus, Rachael M. Roettenbacher, Gail Schaefer, Judit Sturmann, Laszio Sturmann, Theo Ten Brummelaar
[July 2021 Astrophysical Journal (accepted), https://arXiv:2107.02844]

2018

Precision Orbit of δ Delphini and Prospects for Astrometric Detection of Exoplanets
Tyler Gardner, John D. Monnier, Francis C. Fekel, Mike Williamson, Douglas K. Duncan, Timothy R. White, Michael Ireland, Fred C. Adams, Travis Barman, Fabien Baron, Theo ten Brummelaar, Xiao Che, Daniel Huber, Stefan Kraus, Rachel M. Roettenbacher, Gail Schaefer, Judit Sturmann, Laszlo Sturmann
[2018, Astrophys. J., 855, 1]

2017

Kepler sheds new and unprecedented light on the variability of a blue supergiant: gravity waves in the O9.5Iab star HD 188209
C. Aerts, S. Simon-Diaz, S. Bloemen, J. Debosscher, P. Papics, S. Bryson, M. Still, E. Moravveji, M.H. Williamson, F. Grundahl, M. Fredslund Anderson, V. Antoci, P.L. Palle, J. Christensen-Dalsgaard, and T.M. Rogers
[2017, Astronomy & Astrophysics (accepted)]

2016

Orbital Solutions and Absolute Elements of the Massive Algol Binary ET Tauri
Richard Williamon, Horace Dale, Charles L. Evavold, Alexander Langoussis, Francis C. Fekel, Matthew W. Muterspaugh, Stephen Williams, Kate Napier, and James R. Sowell
[2016, PASP, 128:124202]

Very Low-Mass Stellar and Substellar Companions to Solar-like Stars From MARVELS VI: A Giant Planet and a Brown Dwarf Candidate in a Close Binary System HD 87646
Bo Ma, Jian Ge, Alex Wolszczan, Matthew W. Muterspaugh, Brian Lee, Greg Henry, Donald P. Schneider, Eduardo L. Martin, Andrzej Niedzielski, Jiwei Xie, Scott W. Fleming, Neil Thomas, Michael Williamson, Zhaohuan Zhu, Eric Agol, Dmitry Bizyaev, Luiz Nicolaci da Costa, Peng Jiang, A.F. Martinez Fiorenzano, Jonay I. Gonzalez Hernandez, Pengcheng Guo, Nolan Grieves, Rui Li, Jane Liu, Suvrath Mahadevan, Tsevi Mazeh, Duy Cuong Nguyen, Martin Paegert, Sirinrat Sithajan, Keivan Stassun, Sivarani Thirupathi, Julian C. van Eyken, Xiaoke Wan, Ji Wang, John P. Wisniewski, Bo Zhao, Shay Zucker
[2016, Astron. J., (submitted)]

Absolute Properties of the Pre-Main-Sequence Eclipsing Binary Star NP Persei
Claud H. Sandberg Lacy, Francis C. Fekel, Kresimir Pavlovski, Guillermo Torres, and Matthew W. Muterspaugh
[2016, Astron. J., 152, 2]

The Spectroscopic Orbits of Five Gamma Doradus Stars
Francis C. Fekel, Gregory W. Henry, and Dimitri Pourbaix
[2016, Astron. J., 151, 26]

Spectroscopic Orbits for 15 Late-Type Stars
Daryl W. Willmarth, Francis C. Fekel, Helmut A. Abt, and Dimitri Pourbaix
[2016, Astron. J., Volume 152, Number 2, Article 46]

2015

Detecting the Companions and Ellipsoidal Variations of RS CVn Primaries. II. Omicron Draconis, A Candidate for Recent Low-Mass Companion Ingestion
Rachael M. Roettenbacher, John D. Monnier, Francis C. Fekel, Gregory W. Henry, Heidi Korhonen, David W. Latham, Matthew W. Muterspaugh, Michael H. Williamson, Fabien Baron, Theo A. Ten Brummelaar, Xiao Che, Robert O. Harmon, Gail H. Schaefer, Nicholas J. Scott, Judit Sturmann, Laszlo Sturmann, and Nils H. Turner
[2015, Astrophys. J., 809, 159]

Detecting the Companions and Ellipsoidal Variations of RS CVn Primaries. I. Sigma Geminorum
Rachael M. Roettenbacher, John D. Monnier, Gregory W. Henry, Francis C. Fekel, Michael H. Williamson, and 15 others
[2015, Astrophys. J., 807, 23]

HD 207651, A Composite Spectrum Triple System
F.C. Fekel
[2015, Astron. J., 149, 83]

New Precision Orbits of Bright Double-lined Spectroscopic Binaries. IX. HD 54371, HR 2692, 16 Ursa Majoris
F.C. Fekel, M.H. Williamson, M.W. Muterspaugh, D. Willmarth, D. Pourbaix
[2015, Astron. J., 149, 63]

Absolute Properties of the Eclipsing Binary Star IM Persei
C.H.S. Lacy, G. Torres, F.C. Fekel, M.W. Muterspaugh, and J. Southworth
[2015, Astron. J., 149, 34]

2014

Absolute Properties of the Eclipsing Binary Star V501 Herculis
C.H.S. Lacy and F.C. Fekel
[2014, Astron. J. 148, 71]

The Pulsation Amplitude of the Cepheid Polaris Continues to Increase
D.E. Mkrtichian, H. Brunt, Byeong-Cheol Lee, J. Eaton, M. Williamson, F. Fekel, N. Evans, and I. Han
[2014, ASP Conference Series, Vol. 482]

Absolute Properties of the Eclipsing Binary Star AP Andromedae
C.H.S. Lacy, G. Torres, F.C. Fekel, M.W. Muterspaugh
[2014, Astron. J., 147, 148](arXiv)

The Orbit of the Triple-star System 1 Geminorum from Phases Differential Astrometry and Spectroscopy
B.F. Lane, M.W. Muterspaugh, R.F. Griffin, C.D. Scarfe, F.C. Fekel, M.H. Williamson, J.A. Eaton, M. Shao, M.M. Colavita, M. Konacki
[2014, Astrophys. J., 783, 3](pdf)

Orbital Solutions and Absolute Elements of the Eclipsing Binary ES Librae
N.E. Cabrera, J.R. Sowell, R.M. Williamon, T.F Collins, F.C Fekel, M.H. Williamson, and M.W. Muterspaugh
[2014, PASP, 126, 121]

2013

Extensive study of HD 25558, a long-orbital-period double-lined binary with two SPB components
A.Sodor, P. De Cat, D. Wright, C. Neiner, M. Briquet, P. Lampens, R.J. Dukes, F.C. Fekel, G.W. Henry, M.H. Williamson, M.W. Muterspaugh, E. Brunsden, K. Pollard, P.L. Cottrell, F. Maisonneuve, P. Kilmartin, J. Matthews, T. Kallinger, P.G. Beck, E. Kambe, C.A. Engelbrecht, R.J. Czanik, S. Yang, O. Hashimoto, S. Honda, J.N. Fu, B. Castanheira, H. Lehmann, N. Behara, S. Scaringi, H. Van Winkel, J. Menu, A. Lobel, P. Mathias, S. Saesen, M. Vuckovic
[2013, Monthly Notices of the Royal Astronomical Society, submitted]

New Precision Orbits of Bright Double-Lined Spectroscopic Binaries. VIII. HR 1528, HR 6993, 2 Sagittae, and 18 Vulpeculae
F.C. Fekel, J. Tomkin, M.H. Williamson
[2013, Astron. J., 146, 129](IOP)

The Spectroscopic Orbits of Five Solar Type, Single Lined Binaries
F.C. Fekel, S. Rajavi, M.W. Muterspaugh, and M.H. Williamson
[2013, Astron. J., 145, 111]

Absolute Properties of the Eclipsing Binary VV Corvi
F.C. Fekel, G.W. Henry, and J.R. Sowell
[2013, Astron. J., 146, 146]

The spectroscopic orbit of the K-giant binary γ Canis Minoris
Francis C. Fekel, Michael H. Williamson, Michael Weber, Klaus G. Strassmeier, Dimitri Pourbaix
[2013, Astronomische Nachrichten, 3, 223](ps)

2012

Absolute Properties of the Eclipsing Binary Star V335 Serpentis
Claud H. Sandberg Lacy, Francis C. Fekel, and Antonion Claret
[2012, AJ, 144:63](pdf)

A Single-mode Echelle Spectrograph: Eliminating Modal Variation, Enabling Higher Precision Doppler Study
Askari Ghasempour, John Kelly, Matthew W. Muterspaugh, Michael H. Williamson
[2012, ](pdf)

Asteroseismology of the nearby SN-II progenitor: Rigel
Part 1: The MOST high precision photometry and radial velocity monitoring
Ehsan Moravveji, Edward F. Guinan, Matt Shultz, Michael H. Williamson, and Andres Moya
[2012, arXiv:1201.0843v1 [astro-ph.SR]](pdf)

Third Component Search and Abundances of the Very Dusty, Short-Period Binary BD+20 307
Francis C. Fekel, Maria J. Cordero, Raphael Galicher, B. Zuckerman, Carl Melis, and Alicia J. Weinberger
[2012, ApJ, 749, 7]

Absolute Properties of the Eclipsing Binary Star BF Draconis
Claud Lacy, Guillermo Torres, Francis C. Fekel, Jeffrey A. Sabby, and Antonio Claret
[2012, AJ, 143, 129]

2011

Absolute Properties of the Eclipsing Binary Star HY Virginis
Claud H. Sandberg Lacy, Francis C. Fekel
[2011, AJ, 142, 185]

The Real Orbital Period of the Double-Lined Spectroscopic Binary HD 31738
Francis C. Fekel and Roger F. Griffin
[2011, The Observatory, v131, 283]()

New Precision Orbits of Bright Double-lined Spectroscopic Binaries. VII. 47 Andromedae, 38 Cassiopeiae, and HR 8467
Francis C. Fekel, Jocelyn Tomkin, Michael H. Williamson, and Dimitri Pourbaix
[2011, AJ, 142, 69]()

New Precision Orbits of Bright Double-lined Spectroscopic Binaries. VI. HD 24623 and V923 Scorpii
Francis C. Fekel, Michael H. Williamson, and Gregory W. Henry
[2011, AJ, 141, 145]()

2010

The PHASES Differential Astrometry Data Archive. IV.
The Triple Star Systems 63 Gem A and HR 2896
Matthew W. Muterspaugh, Francis C. Fekel, Benjamin F. Lane, William I. Hartkopf, S. R. Kulkarni, Maciej Konacki, Bernard F. Burke, M. M. Colavita, M. Shao, and M. Williamson
[2010, AJ, 140, 1646]

New Precision Orbits of Bright Double-lined Spectroscopic Binaries. V. The Am Stars HD 434 and 41 Sextantis
Francis C. Fekel and Michael H. Williamson
[2010, AJ, 140, 1381]()

New Precision Orbits of Bright Double-lined Spectroscopic Binaries. IV. 66 Andromedae, HR 6979, and HR 9059
Francis C. Fekel, Jocelyn Tomkin, and Michael H. Williamson
[2010, AJ, 139, 1579](pdf)

2009

New Precision Orbits of Bright Double-Lined Spectroscopic Binaries. III. HD 82191, &omega Draconis, and 108 Herculis
Francis C. Fekel, Jocelyn Tomkin, and Michael H. Williamson
[2009, AJ, 137, 3900](pdf)

Asteroseismology of Hybrid Pulsators Made Possible: Simultaneous MOST Space Photometry and Ground-Based Spectroscopy of &gamma Peg
G. Handler, J. M. Matthews, J. A. Eaton, J. Daszyńska-Daszkiewicz, R. Kuschnig, H. Lehmann, E. Rodríguez, A. A. Pamyatnykh, T. Zdravkov, P. Lenz, V. Costa, D. Díaz-Fraile, A. Sota, T. Kwiatkowski, A. Schwarzenberg-Czerny, W. Borczyk, W. Dimitrov, M. Fagas, K. Kamiński, A. Roźek, F. van Wyk, K. R. Pollard, P. M. Kilmartin, W. W. Weiss, D. B. Guenther, A. F. J. Moffat, S. M. Rucinski, D. D. Sasselov, and G. A. H. Walker
[2009, AJ, 698, L56](pdf)

2008

Orbits and Pulsations of the Classical &zeta Aurigae Binaries
Joel A. Eaton, Gregory W. Henry, and Andrew P. Odell
[2008, ApJ, 679, 1490](pdf),

Spurious Eccentricities of Distorted Binary Components
Joel A. Eaton
[2008, ApJ, 681, 562](pdf),

Polaris the Cepheid Returns: 4.5 Years of Monitoring from Ground and Space
H. Bruntt, N. R. Evans, D. Stello, A. J. Penny, J. A. Eaton, D. L. Buzasi, D. D. Sasselov, H. L. Preston, and E. Miller-Ricci
[2008, AJ, 683, 433](pdf),

Planetary Systems around Close Binary Stars: the Case of the Very Dusty, Sun-like, Spectroscopic Binary BD+20 307
B. Zuckerman, Francis C. Fekel, Michael H. Williamson, Gregory W. Henry, and M. P. Muno
[2008, ApJ, 688, 1345](pdf),

2007

The Distribution of Activity on the RS CVn-Type Star SZ Piscium
Joel A. Eaton and Gregory W. Henry
[2007, PASP, 119, 259](pdf),

Starspots and relativity: Applied Doppler imaging for the Gravity Probe B mission
Marsden, S.C., Berdyugina, S.V., Donati, J.-F., Eaton, J.A., Williamson, M.H.
[2007, Astronomische Nachrichten, 328, 1047](pdf),

The Spectroscopic and Astrometric Orbits of HR 672
Francis C. Fekel, Michael H. Williamson, and D. Pourbaix
[2007, AJ, 133, 2431](pdf),

Properties of the &zeta Aur-Type Binary System 22 Vul = QS Vul
Joel A. Eaton and Felecia G. Shaw
[2007, AJ, 133, 2669](pdf)

The Tennessee State University Automatic Spectroscopic Telescope: Data Processing and Velocity Variation of Cool Giants
Joel A. Eaton and Michael H. Williamson
[2007, PASP, 119, 886](pdf)

Chromospherically Active Stars. XXVI. The Double-Lined Late-Type Binary HD 19485 = WZ Arietis
Francis C. Fekel and C. T. Bolton
[2007, AJ, 134, 2079](pdf)

The Orbits of the Quadruple Star System 88 Tauri A from PHASES Differential Astrometry and Radial Velocity
Benjamin F. Lane, Matthew W. Muterspaugh, Francis C. Fekel, Michael Williamson, Stanley Browne, Maciej Konacki, Bernard F. Burke, M. M. Colavita, S. R. Kulkarni, and M. Shao
[2007, AJ, 669, 1209](pdf)

2006

HR 1613: A Slowly Rotating A Dwarf Spectroscopic Binary with Solar Abundances
Fekel, F.C., Willimson, M.H.,Buggs, C., Onuohu, G., and Smith, B.
[2006, AJ, 132, 1490](pdf)

2005

HD 8801: A Unique Single Am Star with &gamma Doradus and &delta Scuti Pulsations
Gregory W. Henry and Francis C. Fekel
[2005, AJ, 129, 2026](pdf)

A Sun in the Spectroscopic Binary IM Pegasi, the Guide Star for the Gravity Probe B Mission
S. C. Marsden, S. V. Berdyugina, J.-F. Donati, J. A. Eaton, M. H. Williamson, I. Ilyin, D. A. Fischer, M. Muñoz, H. Isaacson, M. I. Ratner, M. Semel, P. Petit, and B. D. Carter
[2005, ApJ, 634, L173](pdf)

2004

Managing the operations of the TSU 2-m Automatic Spectroscopic Telescope
Joel A. Eaton and Michael H. Williamson
[2004, Astronomische Nachrichten, 325, 522](pdf)