230 citations · 1.1k across the 52 of their papers we have counts for
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A Surprising Periodicity Detected During a Super-outburst of V844 Herculis by TESS
A. Greiveldinger, P. Garnavich, C. Littlefield +6
We identify a previously undetected periodicity at a frequency of 49.080.01 d (period of 29.340.01 minutes) during a super-outburst of V844 Her observed by TESS. V…
An Eclipsing 47 minute Double White Dwarf Binary at 400 pc
James Munday, P. -E. Tremblay, J. J. Hermes +20
We present the discovery of the eclipsing double white dwarf (WD) binary WDJ 022558.21-692025.38 that has an orbital period of 47.19 min. Following identification with the Transiti…
SDSS J134441.83+204408.3: A highly asynchronous, short-period magnetic cataclysmic variable with a 56 MG field strength
Colin Littlefield, Paul A. Mason, Peter Garnavich +6
When the accreting white dwarf in a magnetic cataclysmic variable star (mCV) has a field strength in excess of 10 MG, it is expected to synchronize its rotational frequency to the…
The Intermediate Polar FO Aquarii Has Not Been the Same Since Recovering from a Series of Low States
Peter Garnavich, Colin Littlefield, Rebecca S. Boyle +1
FO Aqr is a bright intermediate polar that has long displayed large amplitude photometric variations corresponding to the 20.9 min spin period of its white dwarf. Between 2016 and…
A magnetic valve at L1 revealed in TESS photometry of the asynchronous polar BY Cam
Paul A. Mason, Colin Littlefield, Lorena C. Monroy +7
We present TESS photometry of the asynchronous polar BY Cam, which undergoes a beat-cycle between the 199.384-min white dwarf (WD) spin period and the 201.244-min orbital period. T…
Multi-colour optical light curves of the companion star to the millisecond pulsar PSR J2051-0827
V. S. Dhillon, M. R. Kennedy, R. P. Breton +16
We present simultaneous, multi-colour optical light curves of the companion star to the black-widow pulsar PSR J2051-0827, obtained approximately 10 years apart using ULTRACAM and…
Transient two pole accretion in the polar V496 UMa
M. R. Kennedy, C. Littlefield, P. M. Garnavich
We report XMM-Newton and TESS observations of V496 UMa, an AM Herculis-type cataclysmic variable. The XMM-Newton observation reveals that at times, two poles on the white dwarf acc…
Kepler K2 and TESS observations of two magnetic cataclysmic variables: The new asynchronous polar SDSS J084617.11+245344.1 and Paloma
Colin Littlefield, D. W. Hoard, Peter Garnavich +7
There have been relatively few published long-duration, uninterrupted light curves of magnetic cataclysmic variable stars in which the accreting white dwarf's rotational frequency…
Hitting a New Low: The Unique 28 h Cessation of Accretion in the TESS Light Curve of YY Dra (DO Dra)
Katherine L. Hill, Colin Littlefield, Peter Garnavich +6
We present the Transiting Exoplanet Surveying Satellite (TESS) light curve of the intermediate polar YY Draconis (YY Dra, also known as DO Dra). The power spectrum indicates that w…
Rapid bursts of magnetically gated accretion in the intermediate polar V1025 Cen
Colin Littlefield, Jean-Pierre Lasota, Jean-Marie Hameury +5
Magnetically gated accretion has emerged as a proposed mechanism for producing extremely short, repetitive bursts of accretion onto magnetized white dwarfs in intermediate polars (…
Searching for Diamagnetic Blob Accretion in the 74 day K2 Observation of V2400 Ophiuchi
Andrew Langford, Colin Littlefield, Peter Garnavich +3
Since its discovery in 1995, V2400 Ophiuchi (V2400 Oph) has stood apart from most known intermediate polar cataclysmic variables due to its proposed magnetic field strength (9-27 M…
The return of the spin period in DW Cnc and evidence of new high state outbursts
C. Duffy, G. Ramsay, D. Steeghs +16
DW Cnc is an intermediate polar which has previously been observed in both high and low states. Observations of the high state of DW Cnc have previously revealed a spin period at ~…
Quasi-periodic oscillations in the TESS light curve of TX Col, a diskless intermediate polar on the precipice of forming an accretion disk
Colin Littlefield, Simone Scaringi, Peter Garnavich +4
One of the fundamental properties of an intermediate polar is the dynamical nature of the accretion flow as it encounters the white dwarf's magnetosphere. Many works have presumed…
Short-cadence K2 observations of an accretion-state transition in the polar Tau 4
Colin Littlefield, Peter Garnavich, Paula Szkody +5
The Kepler spacecraft observed a total of only four AM Herculis cataclysmic variable stars during its lifetime. We analyze the short-cadence K2 light curve of one of those systems,…
The Rise and Fall of the King: The Correlation between FO Aquarii's Low States and the White Dwarf's Spindown
Colin Littlefield, Peter Garnavich, Mark R. Kennedy +45
The intermediate polar FO Aquarii (FO Aqr) experienced its first-reported low-accretion states in 2016, 2017, and 2018, and using newly available photographic plates, we identify p…
Fast-Cadence TESS Photometry and Doppler Tomography of the Asynchronous Polar CD Ind: A Revised Accretion Geometry from Newly Proposed Spin and Orbital Periods
Colin Littlefield, Peter Garnavich, Koji Mukai +5
The TESS spacecraft observed the asynchronous polar CD Ind at a two-minute cadence almost continuously for 28 days in 2018, covering parts of 5 consecutive cycles of the system's 7…
Driving the Beat: Time-Resolved Spectra of the White Dwarf Pulsar AR Scorpii
Peter Garnavich, Colin Littlefield, Stella Kafka +4
We obtained high temporal resolution spectroscopy of the unusual binary system AR Sco covering nearly an orbit. The H emission shows a complex line structure similar to that see…
A Phenomenological Model for the Light Curve of three Quiescent Low-inclination Dwarf Novae and one Pre-Cataclysmic Variable
Zhibin Dai, Paula Szkody, Mark Kennedy +5
We used the light curve code XRBinary to model the quiescent K2 light curves of three low-inclination cataclysmic variables (CVs): 1RXS\,J0632+2536 (J0632+2536), RZ\,Leo, TW\,Vir a…
K2 study of the Magnetic Precataclysmic Variable V1082 Sagittarius
Gagik Tovmassian, Paula Szkody, Ricardo Yarza +1
We present a long-term light curve of the precataclysmic variable (CV) V1082 Sgr obtained by the K2-mission over the course of 81 days. We analyze the entire complex light curve as…
A Comprehensive K2 and Ground-Based Study of CRTS J035905.9+175034, an Eclipsing SU UMa System with a Large Mass Ratio
Colin Littlefield, Peter Garnavich, Mark Kennedy +2
CRTS J035905.9+175034 is the first eclipsing SU UMa system for which a superoutburst has been observed by Kepler in the short-cadence mode. The light curve contains one superoutbur…
MASTER OT J132104.04+560957.8: A Polar with Absorption-Emission Line Reversals
Colin Littlefield, Peter Garnavich, Taylor Hoyt +1
We present time-resolved photometry and spectroscopy of the recently classified polar MASTER OT J132104.04+560957.8. The spectrum shows a smooth, non-thermal continuum at the time…
Quiescent photometric modulations of two low-inclination cataclysmic variables KZGem and TWVir
Zhibin Dai, Paula Szkody, Ali Taani +2
The quiescent periodic photometric modulations of two low-inclination cataclysmic variables observed in Kepler K2 Campaigns 0 and 1, KZ Gem and TW Vir, are investigated. A phase-co…
Long-term photometric variations in the candidate white-dwarf pulsar AR Scorpii from K2, CRTS, and ASAS-SN observations
Colin Littlefield, Peter Garnavich, Mark Kennedy +3
We analyze long-cadence Kepler K2 observations of AR Sco from 2014, along with survey photometry obtained between 2005 and 2016 by the Catalina Real-Time Sky Survey and the All-Sky…
Return of the King: Time-Series Photometry of FO Aquarii's Initial Recovery from its Unprecedented 2016 Low State
Colin Littlefield, Peter Garnavich, Mark R. Kennedy +28
In 2016 May, the intermediate polar FO~Aqr was detected in a low state for the first time in its observational history. We report time-resolved photometry of the system during its…