86 citations · 974 across the 74 of their papers we have counts for
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A Refined Orbital Ephemeris for the Intermediate Polar FO Aquarii and Evidence for a Period Derivative
Peter Garnavich, Jordan Tweddale, Colin Littlefield
We combine more than 40 years of eclipse timings of the intermediate polar FO Aqr and derive new orbital ephemerides. The eclipse times are best fit with a second order polynomial,…
HST Observations of the CV Propeller LAMOST J024048.51+195226.9
Jordan Tweddale, Peter Garnavich, Colin Littlefield +1
We present Hubble Space Telescope (HST) FUV spectra and light curves of the magnetic cataclysmic variable (CV) LAMOST J024048.51+195226.9 (J0240), the second known CV propeller. Th…
An Eccentric Planet Orbiting the Polar V808 Aurigae
McKenna Leichty, Peter Garnavich, Colin Littlefield +4
We analyze 15 years of eclipse timings of the polar V808 Aur. The rapid ingress/egress of the white dwarf and bright accretion region provide timings as precise as a few tenths of…
Classifying optical (out)bursts in cataclysmic variables: the distinct observational characteristics of dwarf novae, micronovae, stellar flares and magnetic gating
Krystian Ilkiewicz, Simone Scaringi, Martina Veresvarska +5
Cataclysmic variables can experience short optical brightenings, which are commonly attributed to phenomena such as dwarf novae outbursts, micronovae, donor flares or magnetic gati…
Rapid Evolution of the White Dwarf Pulsar AR Scorpii
Peter Garnavich, Stephen B. Potter, David A. H. Buckley +4
Analysis of AR Sco optical light curves spanning nine years show a secular change in the relative amplitudes of the beat pulse pairs generated by the two magnetic poles of its rota…
A Phenomenon Resembling Early Superhumps in a New SU UMa-Type Dwarf Nova with a 2-Hour Orbital Period
Rebecca Boyle, Colin Littlefield, Peter Garnavich +4
We investigate K2BS5, an optical transient that we identified in Campaign 13 of the Kepler/K2 archives by the "K2 Background Survey", and classify it as a new SU UMa-type dwarf nov…
Visual Orbits & Alignments of Planet Hosting Binary Systems
Kathryn Lester, Steve Howell, Rachel Matson +7
Roughly half of Solar-type planet hosts have stellar companions, so understanding how these binary companions affect the formation and evolution of planets is an important componen…
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…
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…
Three low-mass companions around aged stars discovered by TESS
Zitao Lin, Tianjun Gan, Sharon X. Wang +42
We report the discovery of three transiting low-mass companions to aged stars: a brown dwarf (TOI-2336b) and two objects near the hydrogen burning mass limit (TOI-1608b and TOI-252…
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…
Locating the flickering source in polars
Krystian Ilkiewicz, Simone Scaringi, Colin Littlefield +1
Flickering is a fast variability observed in all accreting systems. It has been shown that in most cataclysmic variables flickering originates in the accretion disc. However, in po…
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…
Characteristics of the Permanent Superhumps in V533 Herculis
McKenna Leichty, Peter Garnavich, Colin Littlefield +2
We analyze two sectors of TESS photometry of the nova-like cataclysmic variable star V533 Her. We detect a periodicity consistent with the binary orbital period and estimate a revi…
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…
Investigating the low-flux states in six Intermediate Polars
Ava E. Covington, Aarran W. Shaw, Koji Mukai +30
We present optical photometry of six intermediate polars that exhibit transitions to a low-flux state. For four of these systems, DW Cnc, V515 And, V1223 Sgr and RX J2133.7+5107, 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…
An accreting white dwarf displaying fast transitional mode switching
S. Scaringi, D. de Martino, D. H. Buckley +6
Accreting white dwarfs are often found in close binary systems with orbital periods ranging from tens of minutes to several hours. In most cases, the accretion process is relativel…
Spectroscopy of the Proposed White Dwarf Pulsar ASASSN-V J205543.90+240033.5
R. Mark Wagner, Peter Garnavich, John R. Thorstensen +2
We obtained spectra of ASASSN-V J205543.90+240033.5 (J2055), a system that shows photometric variations similar to the white dwarf (WD) pulsar AR Scorpii (Kato et al. arXiv:2109.03…
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…
Exploring the tilted accretion disc of AQ Men with TESS
Krystian Ilkiewicz, Simone Scaringi, James M. C. Court +8
AQ Men is a nova-like variable which is presumed to have a tilted, precessing accretion disc. Grazing eclipses in this system have been speculated to be useful in exploring the geo…