English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

The TESS spacecraft observed the asynchronous polar CD Ind at a two-minutecadence almost continuously for 28 days in 2018, covering parts of 5consecutive cycles of the system's 7.3-day beat period. These observationsprovide the first uninterrupted photometry of a full spin-orbit beat cycle ofan asynchronous polar. Twice per beat cycle, the accretion flow switchedbetween magnetic poles on the white dwarf, causing the spin pulse of the whitedwarf (WD) to alternate between two waveforms after each pole-switch. Ananalysis of the waveforms suggests that one accretion region is continuouslyvisible when it is active, while the other region experiences lengthyself-eclipses by the white dwarf. We argue that the previously accepted periodsfor both the binary orbit and the WD spin have been misidentified, and whilethe cause of this misidentification is a subtle and easily overlooked effect,it has profound consequences for the interpretation of the system's accretiongeometry and doubles the estimated time to resynchronization. Moreover, ourtimings of the photometric maxima do not agree with the quadratic ephemerisfrom Myers et al. (2017), and it is possible that the optical spin pulse mightbe an unreliable indicator of the white dwarf's rotation. Finally, we useDoppler tomography of archival time-resolved spectra from 2006 to study theaccretion flow. While the accretion flow showed a wider azimuthal extent thanis typical for synchronous polars, it was significantly less extended than inthe three other asynchronous polars for which Doppler tomography has beenreported.

astrophysical journal/the astrophysical journal

Fast-Cadence TESS Photometry and Doppler Tomography of the Asynchronous  Polar CD Ind: A Revised Accretion Geometry from Newly Proposed Spin and  Orbital Periods