2001A&A...375..485F


C.D.S. - SIMBAD4 rel 1.7 - 2020.08.13CEST10:48:45

2001A&A...375..485F - Astronomy and Astrophysics, volume 375, 485-491 (2001/8-4)

Coronal structure geometries on pre-main sequence stars.

FAVATA F., MICELA G. and REALE F.

Abstract (from CDS):

Using a hydrodynamic model we have re-analyzed large flaring events on three different categories of pre-main sequence (PMS) stars: the young stellar object (YSO) YLW15, the classical T Tauri star (CTTS) LkHα92, the weak-line T Tauri star (WTTS) V773 Tau, and the WTTS HD 283572 (the first three objects were observed by ASCA, the last by ROSAT; all observations have been previously reported in the literature). The first three flares were previously analyzed on the basis of a quasi-static model mostly used up to now, consistently yielding large loops (L>R*) and no evidence of sustained heating. Our hydrodynamic modeling approach, however, shows that the size of the flaring regions must be much smaller (L≲R*) and moreover this method shows in all cases evidence of vigorous sustained heating during the flare decay, so that the decay of the observed light curve actually reflects the temporal profile of the heating rather than that of the free decay of the heated loop(s). The events on the protostar YLW15 have durations comparable to the stellar rotation period, so that their limited size and their lack of self-eclipses give evidence of a polar location on the star. This is in contrast with the recently advanced hypothesis that these flares are due to long loops spanning the region between the star and the accretion disk. In general, the present analysis shows that flaring coronae on PMS stars have a structure similar to the coronae on older active stars.

Abstract Copyright:

Journal keyword(s): stars: late-type - activity - coronae - X-rays: stars

Simbad objects: 15

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Number of rows : 15

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* CF Tuc RS* 00 53 07.7682099536 -74 39 05.609032263   8.31 7.90   6.730 G2/5V+F0 216 0
2 * bet Per Al* 03 08 10.1324535 +40 57 20.328013 1.70 2.07 2.12 2.08 2.11 B8V 1147 2
3 EM* LkHA 92 Or* 03 44 26.0272032386 +32 04 30.452350791   17.13 15.06   12.686 ~ 69 0
4 IC 348 OpC 03 44 34 +32 09.8           ~ 1231 1
5 Barnard 209 DNe 04 12.4 +28 19           ~ 19 0
6 HD 283447 Or* 04 14 12.9232870093 +28 12 12.378540314 13.17 12.07 10.68 9.45 8.67 K3Ve 381 0
7 HD 283572 Or* 04 21 58.8482823933 +28 18 06.511915195   9.80 9.03 9.14   G5IVe 268 0
8 NAME Tau-Aur Complex SFR 04 30 +25.0           ~ 1217 0
9 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
10 BD+20 2465 Er* 10 19 36.2808024653 +19 52 12.014037746   10.82 9.52 9.19   M4Vae 1152 0
11 V* CM Leo RR* 11 56 14.2301497015 +21 15 30.232268663           ~ 21 0
12 YLW 15 Y*O 16 27 26.93640 -24 40 50.8224           ~ 241 1
13 NAME Ophiuchus Molecular Cloud SFR 16 28 06 -24 32.5           ~ 3038 0
14 V* AR Lac RS* 22 08 40.8180372773 +45 44 32.104045703 7.09 6.83 6.11     K0IVe+G5IV 696 0
15 V* EV Lac Er* 22 46 49.7311740821 +44 20 02.372223230   11.85 10.26 9.89   M4.0V 802 2

    Equat.    Gal    SGal    Ecl

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2020.08.13-10:48:45

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