2022AJ....163....4L


Query : 2022AJ....163....4L

2022AJ....163....4L - Astron. J., 163, 4-4 (2022/January-0)

Searching for diamagnetic blob accretion in the 74 day K2 observation of V2400 Ophiuchi.

LANGFORD A., LITTLEFIELD C., GARNAVICH P., KENNEDY M.R., SCARINGI S. and SZKODY P.

Abstract (from CDS):

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 MG) and diskless accretion. To date, the exact accretion mechanism of the system is still unknown, and standard accretion models fail to accurately predict the peculiar behavior of its light curve. We present the K2 Campaign 11 light curve of V2400 Oph recording 74.19 days of photometric data cadenced at 1 minute. The light curve is dominated by aperiodic flickering and quasiperiodic oscillations, which make the beat and spin signals inconspicuous on short timescales. Notably, a log-log full power spectrum shows a break frequency at ∼102 cycles d–1 similar to some disk-fed systems. Through power-spectral analysis, the beat and spin periods are measured as 1003.4 ± 0.2 s and 927.7 ± 0.1 s, respectively. A power spectrum of the entire K2 observation demonstrates beat period dominance. However, time-resolved power spectra reveal a strong dependence between observation length and the dominant frequency of the light curve. For short observations (2-12 hr) the beat, spin, or first beat harmonic can be observed as the dominant periodic signal. Such incoherence and variability indicate a dynamical accretion system more complex than current intermediate polar theories can explain. We propose that a diamagnetic blob accretion model may serve as a plausible explanation for the accretion mechanism.

Abstract Copyright: © 2021. The Author(s). Published by the American Astronomical Society.

Journal keyword(s): Cataclysmic variable stars - Stellar accretion - DQ Herculis stars - Photometry - Close binary stars

Simbad objects: 6

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Number of rows : 6
N Identifier Otype ICRS (J2000)
RA
ICRS (J2000)
DEC
Mag U Mag B Mag V Mag R Mag I Sp type #ref
1850 - 2026
#notes
1 V* TX Col CV* 05 43 20.16864 -41 01 54.2856         14.541 ~ 167 0
2 V* RZ Leo CV* 11 37 22.2524330304 +01 48 58.617459936     19.6     DA+dM2 170 0
3 V* V2400 Oph CV* 17 12 36.4233668016 -24 14 44.773987164     14.5     ~ 169 0
4 IGR J18044-2739 X 18 04 31.1 -27 39 32           ~ 20 3
5 V* MV Lyr CV* 19 07 16.2886463256 +44 01 07.869892008   13.040 12.920 12.489 12.578 M5Ve 307 0
6 V* FO Aqr CV* 22 17 55.3796835600 -08 21 03.754995948   13.533 13.445 13.414   ~ 378 0

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