2014A&A...572L...6L


C.D.S. - SIMBAD4 rel 1.7 - 2020.07.13CEST00:28:26

2014A&A...572L...6L - Astronomy and Astrophysics, volume 572, L6-6 (2014/12-1)

On the correlation between stellar chromospheric flux and the surface gravity of close-in planets.

LANZA A.F.

Abstract (from CDS):

The chromospheric emission of stars with close-in transiting planets has been found to correlate with the surface gravity of their planets. Stars with low-gravity planets have on average a lower chromospheric flux. We propose that this correlation is due to the absorption by circumstellar matter that comes from the evaporation of the planets. Planets with a lower gravity have a greater mass-loss rate, which leads to a higher column density of circumstellar absorption and in turn explains the lower level of chromospheric emission observed in their host stars. We estimated the required column density and found that planetary evaporation can account for it. We derived a theoretical relationship between the chromospheric emission as measured in the core of the Ca II H&K lines and the planet gravity. We applied this relationship to a sample of transiting systems for which both the stellar Ca II H&K emission and the planetary surface gravity are known and found a good agreement, given the various sources of uncertainties and the intrinsic variability of the stellar emissions and planetary evaporation rates. We consider implications for the radial velocity jitter applied to fit the spectroscopic orbits and for the age estimates of planetary systems based on the chromospheric activity level of their host stars.

Abstract Copyright:

Journal keyword(s): planetary systems - stars: activity - stars: chromospheres - circumstellar matter

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 - 2020
#notes
1 HD 10069 * 01 37 25.0335097438 -45 40 40.376513381   9.74 9.30     F6IV/V 153 1
2 V* AB Dor TT* 05 28 44.8916324761 -65 26 55.289846904 8.259 7.856 6.999 6.496 5.993 K0V 931 0
3 WASP-12 ** 06 30 32.7966788910 +29 40 20.266334158   12.14 11.57     G0V 229 2
4 CD-27 10695b Pl 15 59 50.9489706053 -28 03 42.309432433           ~ 196 1
5 CoRoT-2 * 19 27 06.4944821296 +01 23 01.357597206   13.422 12.568 12.204 11.49 G7V+K9V 211 2
6 HD 189733 BY* 20 00 43.7130382888 +22 42 39.071811263 9.241 8.578 7.648 7.126 6.68 K2V 720 1

    Equat.    Gal    SGal    Ecl

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2020.07.13-00:28:26

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