VLBI detection of the AE Aqr twin, LAMOST J024048.51+195226.9
Journal article, 2024

LAMOST J024048.51+195226.9 (J0240+1952) was recently identified as the second AE Aquarii (AE Aqr)-type cataclysmic variable, possessing the fastest known rotating white dwarf. We performed a Very Long Baseline Interferometry (VLBI) observation of J0240+1952 utilizing the European VLBI Network at 1.7 GHz, to obtain the first view of the radio morphology on mas scale. Our high-resolution VLBI image clearly shows that the radio emission is compact on mas scale (≲2 AU), with no evidence for a radio jet or extended emission. The compact radio source has an average flux density of ∼0.37 mJy, and its brightness temperature is given at ∼2.3 × 107 K, confirming a non-thermal origin. The emission exhibits irregular variations on a time-scale of tens of minutes, similar to the radio flares seen in AE Aqr. The measured VLBI position of J0240+1952 is consistent with that derived from Gaia. Our results favour the model in which the radio emission is attributed to a superposition of synchrotron radiation from expanding magnetized blobs of this system.

stars: magnetic field

radio continuum: stars

white dwarfs

techniques: high angular resolution

Author

Pengfei Jiang

Chinese Academy of Sciences

Xinjiang Astronomical Observatory

Lang Cui

Xinjiang Astronomical Observatory

Chinese Academy of Sciences

Xiang Liu

Chinese Academy of Sciences

Xinjiang Astronomical Observatory

Bo Zhang

Chinese Academy of Sciences

Yongfeng Huang

Nanjing University

Hong Min Cao

Shangqiu Normal University

T. An

Xinjiang Astronomical Observatory

Chinese Academy of Sciences

Jun Yang

Chalmers, Space, Earth and Environment, Onsala Space Observatory

Fengchun Shu

Chinese Academy of Sciences

Guiping Tan

Xinjiang Astronomical Observatory

Jianping Yuan

Xinjiang Astronomical Observatory

Monthly Notices of the Royal Astronomical Society: Letters

17453925 (ISSN) 17453933 (eISSN)

Vol. 528 1 L112-L116

Subject Categories (SSIF 2011)

Astronomy, Astrophysics and Cosmology

Fusion, Plasma and Space Physics

DOI

10.1093/mnrasl/slad178

More information

Latest update

3/16/2025