ATTENZIONE!!! IL SISTEMA E' UTILIZZABILE ESCLUSIVAMENTE IN MODALITA' "CONSULTAZIONE". CAUSA PROBLEMI TECNICI, SI PREGA DI NON EFFETTUARE L'AUTENTICAZIONE, FINO A NUOVA COMUNICAZIONE. GRAZIE
 

Magnetic field strengths of hot Jupiters from signals of star–planet interactions

Journal
Date Issued
2019
Author(s)
Cauley, P. Wilson
•
Shkolnik, Evgenya L.
•
Llama, Joe
•
DOI
Abstract
Evidence of star-planet interactions in the form of planet-modulated chromospheric emission has been noted for a number of hot Jupiters. Magnetic star-planet interactions involve the release of energy stored in the stellar and planetary magnetic fields. These signals thus offer indirect detections of exoplanetary magnetic fields. Here, we report the derivation of the magnetic field strengths of four hot Jupiter systems, using the power observed in Ca II K emission modulated by magnetic star-planet interactions. By approximating the fractional energy released in the Ca II K line, we find that the surface magnetic field values for the hot Jupiters in our sample range from 20 G to 120 G, around 10-100 times larger than the values predicted by dynamo scaling laws for planets with rotation periods of around 2-4 days. However, these values are in agreement with scaling laws relating the magnetic field strength to the internal heat flux in giant planets. Large planetary magnetic field strengths may produce observable electron-cyclotron maser radio emission by preventing the maser from being quenched by the planet's ionosphere. Intensive radio monitoring of hot Jupiter systems will help to confirm these field values and inform the generation mechanism of magnetic fields in this important class of exoplanets.
Volume
3
Issue
12
Start page
1128
Uri
Url
Issn Identifier
2397-3366
Rights
open.access
File(s)
Loading...
Thumbnail Image
Name

s41550-019-0840-x_Cauleyetal19.pdf

Description
[Administrators only]
Size

1.66 MB

Format

Adobe PDF

Checksum (MD5)

14314f3c3c80112c0b185cf6e377aa65

Loading...
Thumbnail Image
Name

Cauleyetal19.pdf

Description
preprint
Size

760.23 KB

Format

Adobe PDF

Checksum (MD5)

f8fecf2ff76534efee919afbacf5589e