Discovery of a magnetic field in $\rho$ Pup

Abstract

$\rho$ Pup is a $\delta$ Scuti F2 pulsator, known to host a main radial mode as well as non-radial pulsations, with chemical peculiarities typical of evolved Am stars. We present high-precision spectropolarimetric observations of this star, obtained with ESPaDOnS at the Canada France Hawaii Telescope (CFHT) in the frame of the BRITE spectropolarimetric survey. A magnetic field is clearly detected in $\rho$ Pup, with a longitudinal field strength below 1 G. This makes $\rho$ Pup the second known magnetic $\delta$ Scuti discovered, after HD 188774, and a possible cool evolved counterpart of the recently discovered ultra-weakly magnetic Am family.

4 pages, 2 figures, accepted in MNRAS Letters

References in corpus (4)

• Turbulent convection and pulsation stability of stars - II. Theoretical instability strip for $\delta$ Scuti and $\gamma$ Doradus stars
• The role of turbulent pressure as a coherent pulsational driving mechanism: the case of the delta Scuti star HD 187547
• Detection of ultra-weak magnetic fields in Am stars: beta UMa and theta Leo
• Discovery of a very weak magnetic field on the Am star Alhena

Cited by in corpus (18)

• Theory and evidence of global Rossby waves in upper main-sequence stars: r-mode oscillations in many Kepler stars
• On the first $\delta$ Sct--roAp hybrid pulsator and the stability of p and g modes in chemically peculiar A/F stars
• Testing the fossil field hypothesis: could strongly magnetised OB stars produce all known magnetars?
• Detection of magnetic fields in chemically peculiar stars observed with the K2 space mission
• Eclipsing Systems with Pulsating Components (Types β Cep, δ Sct, γ Dor or Red Giant) in the Era of High-Accuracy Space Data
• Detecting deep axisymmetric toroidal magnetic fields in stars. The traditional approximation of rotation for differentially rotating deep spherical shells with a general azimuthal magnetic field
• Rotation and spots in normal A and Am/Fm stars
• Rotational modulation in A and F stars: Magnetic stellar spots or convective core rotation?
• The complex fossil magnetic field of the $\delta$ Scuti star HD\,41641
• Study of Chemically Peculiar Stars-I : High-resolution Spectroscopy and K2 Photometry of Am Stars in the Region of M44
• Space Photometry with BRITE-Constellation
• Variability and stellar pulsation incidence in Am/Fm stars using TESS and Gaia data
• Searching for magnetic fields in pulsating A-type stars: the discovery of a strong field in the probable delta Sct star HD340577 and a null result for the gamma Dor star HR8799
• A revisit to the enigmatic variable star 21 Comae
• A conclusive non-detection of magnetic field in the Am star o Peg with high-precision near-infrared spectroscopy
• Magnetic Fields or Overstable Convective Modes in HR 7495: Exploring the Underlying Causes of the Spike in the 'Hump & Spike' Features
• Discovery of new magnetic δ Scuti stars and impact of magnetism on pulsation excitation
• Determining the incidence rate of magnetic $\delta$ Scuti candidates with CoRoT