The fifth main sequence magnetic B-type star showing coherent radio emission: is this really a rare phenomenon?

Abstract

We report the discovery of intense, highly directional radio emission from the Bp star HD 35298, which we interpret as the consequence of Electron Cyclotron Maser Emission (ECME). The star was observed with the Giant Metrewave Radio Telescope near the rotational phases of both magnetic nulls in band 4 (550-750 MHz) and one of the nulls in band 5 (1060-1460 MHz). In band 4, we observed flux density enhancement in both circular polarizations near both magnetic nulls. The sequences of arrival of the left and right circularly polarized pulses are opposite near the two nulls. In band 5, we did not have circular polarization information and hence measured only the total intensity lightcurve, which also shows enhancement around the magnetic null. The observed sequence of the circular polarization signs in band 4, compared with the longitudinal magnetic field curve, is able to locate the hemisphere from which ECME arises. This observational evidence supports the scenario of ECME in the ordinary mode, arising in a magnetosphere shaped like an oblique dipole. HD 35298 is the most slowly rotating and most distant main sequence magnetic star from which ECME has been observed.

Accepted for publication in MNRAS Letters

References in corpus (13)

• Confirmation of the Electron Cyclotron Maser Instability as the Dominant Source of Radio Emission from Very Low Mass Stars and Brown Dwarfs
• Periodic Bursts of Coherent Radio Emission from an Ultracool Dwarf
• Evolutionary state of magnetic chemically peculiar stars
• Rotational Modulation of the Radio Emission from the M9 Dwarf TVLM 513-46546: Broadband Coherent Emission at the Substellar Boundary?
• Magnetic field topology of the unique chemically peculiar star CU Virginis
• The Magnetic Early B-type Stars I: Magnetometry and Rotation
• Stellar magnetosphere reconstruction from radio data. Multi-frequency VLA observations and 3D-simulations of CU Virginis
• The detection of variable radio emission from the fast rotating magnetic hot B-star HR7355 and evidence for its X-ray aurorae
• The radio lighthouse CU Virginis: the spindown of a single main sequence star
• Magnetic field topology and chemical abundance distributions of the young, rapidly rotating chemically peculiar star HR5624
• The Magnetic Early B-type Stars II: stellar atmospheric parameters in the era of Gaia
• Discovery of electron cyclotron MASER emission from the magnetic Bp star HD 133880 with the Giant Metrewave Radio Telescope
• Detection of coherent emission from the Bp star HD 142990 at uGMRT frequencies

Cited by in corpus (13)

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• Evidence for radio and X-ray auroral emissions from the magnetic B-type star rho Oph A
• The auroral radio emission of the magnetic B-type star rho OphC
• Testing a scaling relation between coherent radio emission and physical parameters of hot magnetic stars
• Unraveling the complex magnetosphere of the B star HD 133880 via wideband observation of coherent radio emission
• Tackling the Unique Challenges of Low-frequency Solar Polarimetry with the Square Kilometre Array Low Precursor: Pipeline Implementation
• What leads to premature upper cut-off frequencies of auroral radio emission from hot magnetic stars?
• Discovery and origin of the radio emission from the multiple stellar system KQVel
• One of Everything: The Breakthrough Listen Exotica Catalog
• Ultra-Wideband, Multi-epoch Radio Study of the First Discovered `Main sequence Radio Pulse emitter' CU Vir
• Discovery of eight 'Main-sequence Radio Pulse emitters' using the GMRT: clues to the onset of coherent radio emission in hot magnetic stars