J/A+A/463/1017 B and V light curves of AA Tau (Bouvier+, 2007)
Magnetospheric accretion-ejection processes in the classical
T Tauri star AA Tau.
Bouvier J., Alencar S.H.P., Boutelier T., Dougados C., Balog Z., Grankin K.,
Hodgkin S.T., Ibrahimov M.A., Kun M., Magakian T.Yu., Pinte C.
<Astron. Astrophys. 463, 1017 (2007)>
=2007A&A...463.1017B 2007A&A...463.1017B
ADC_Keywords: Stars, pre-main sequence; Photometry, UBV
Keywords: accretion, accretion disks - stars: pre-main sequence -
stars: magnetic fields - stars: individual: AA Tau
Abstract:
From a long time series of high resolution (R=115,000) HARPS spectra
and simultaneous broad-band photometry, we report new evidence for
magnetospheric accretion as well as ejection processes in the nearly
edge-on classical T Tauri star AA Tau. AA Tau's light curve is
modulated with a period of 8.22d. The recurrent luminosity dips are
due to the periodic occultation of the central star by the
magnetically-warped inner disk edge located at about 9R*.
Balmer line profiles exhibit a clear rotational modulation of
high-velocity redshifted absorption components with a period of
8.22-days as well, with a maximum strength when the main accretion
funnel flow passes through the line of sight. At the same time, the
luminosity of the system decreases by about 1mag, indicative of
circumstellar absorption of the stellar photosphere by the
magnetically-warped, corotating inner disk edge. The photospheric and
HeI radial velocities also exhibit periodic variations, and the
veiling is modulated by the appearance of the accretion shock at the
bottom of the accretion funnel. Diagnostics of hot winds and their
temporal behaviour are also presented. The peculiar geometry of the
young AA Tau system (nearly edge-on) allows us to uniquely probe the
accretion-ejection region close to the star. We find that most
spectral and photometric diagnostics vary as expected from models of
magnetically-channelled accretion in young stars, with a large scale
magnetosphere tilted by 20° onto the star's spin axis. We also
find evidence for time variability of the magnetospheric accretion
flow on a timescale of a few rotational periods.
Description:
B- and V-band photometric observations of AA Tau are listed from
JD2453260.48 to JD2453396.32.
Objects:
---------------------------------------------
RA (2000) DE Designation(s)
---------------------------------------------
04 34 55.4 +24 28 53 AA Tau = V* AA Tau
---------------------------------------------
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
aatau.dat 19 214 V- and B-band measurements
--------------------------------------------------------------------------------
Byte-by-byte Description of file: aatau.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 10 F10.2 d JD Julian Date
12 A1 --- Band [BV] Photometric band
14- 19 F6.3 mag mag B or V magnitude
--------------------------------------------------------------------------------
Acknowledgements:
Jerome Bouvier, jbouvier(at)obs.ujf-grenoble.fr
(End) Patricia Vannier [CDS] 30-Nov-2006