2015A&A...574A..25J


C.D.S. - SIMBAD4 rel 1.7 - 2020.02.27CET08:21:15

2015A&A...574A..25J - Astronomy and Astrophysics, volume 574A, 25-25 (2015/2-1)

Doppler images and the underlying dynamo. The case of AF Leporis.

JAERVINEN S.P., ARLT R., HACKMAN T., MARSDEN S.C., KUEKER M., ILYIN I.V., BERDYUGINA S.V., STRASSMEIER K.G. and WAITE I.A.

Abstract (from CDS):

The (Zeeman-)Doppler imaging studies of solar-type stars very often reveal large high-latitude spots. This also includes F stars that possess relatively shallow convection zones, indicating that the dynamo operating in these stars differs from the solar dynamo. We aim to determine whether mean-field dynamo models of late-F type dwarf stars can reproduce the surface features recovered in Doppler maps. In particular, we wish to test whether the models can reproduce the high-latitude spots observed on some F dwarfs. The photometric inversions and the surface temperature maps of AF Lep were obtained using the Occamian-approach inversion technique. Low signal-to-noise spectroscopic data were improved by applying the least-squares deconvolution method. The locations of strong magnetic flux in the stellar tachocline as well as the surface fields obtained from mean-field dynamo solutions were compared with the observed surface temperature maps. The photometric record of AF Lep reveals both long- and short-term variability. However, the current data set is too short for cycle-length estimates. From the photometry, we have determined the rotation period of the star to be 0.9660±0.0023-days. The surface temperature maps show a dominant, but evolving, high-latitude (around +65°) spot. Detailed study of the photometry reveals that sometimes the spot coverage varies only marginally over a long time, and at other times it varies rapidly. Of a suite of dynamo models, the model with a radiative interior rotating as fast as the convection zone at the equator delivered the highest compatibility with the obtained Doppler images.

Abstract Copyright:

Journal keyword(s): stars: imaging - stars: activity - starspots - stars: individual: AF Lep - dynamo

Simbad objects: 13

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Number of rows : 13

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 V* AE Phe WU* 01 32 32.9321973079 -49 31 41.290852285   8.75 8.15     G4V 112 0
2 V* OU Tau Fl* 03 45 32.9382648825 +24 18 11.647131333   14.63 13.36   12.02 K4V 81 0
3 V* V816 Tau BY* 03 51 53.3859483764 +24 23 13.077396311   13.67 12.69   11.54 K0V 65 0
4 HD 34538 RG* 05 17 40.2416240637 -13 31 11.371562025   6.436 5.488     G8IV 57 0
5 V* AF Lep RS* 05 27 04.7631691589 -11 54 03.466187467   6.832 6.295     F8V(n)k: 203 0
6 HD 36705 TT* 05 28 44.8916324761 -65 26 55.289846904 8.259 7.856 6.999 6.496 5.993 K0V 921 0
7 HD 36379 PM* 05 30 59.9404041031 -10 04 51.904429406   7.47 6.91     G2V 63 0
8 V* V557 Car BY* 10 42 41.5159999215 -64 21 04.332236022   11.26 12.03     G2V 50 0
9 * tau Boo ** 13 47 15.74340 +17 27 24.8552 5.02 4.98 4.49 4.09 3.85 F7IV-V 868 1
10 NAME beta Pic Moving Group MGr 14 30 -42.0           ~ 535 0
11 V* LQ Lup TT* 15 08 37.7352828737 -44 23 17.050344716 11.46 11.54 10.645 10.22 9.804 G8IVe 64 0
12 * sig CrB A SB* 16 14 40.8535709806 +33 51 31.006121827   6.14 5.55     F6V 36 1
13 BD+22 4409 BY* 21 31 01.7141405072 +23 20 07.370852589   10.28 9.253 8.6 7.965 K3Vke 150 0

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2020.02.27-08:21:15

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