J/ApJ/728/69 Photoelectric photometry of V410 Tauri (Rice+, 2011)
The surface of V410 Tauri.
Rice J.B., Strassmeier K.G., Kopf M.
<Astrophys. J., 728, 69 (2011)>
=2011ApJ...728...69R 2011ApJ...728...69R
ADC_Keywords: Photometry ; Stars, pre-main sequence
Keywords: stars: imaging - stars: individual (V410 Tau) - starspots
Abstract:
We present Doppler images of the weak-lined T Tauri star V410 Tau
obtained with two different Doppler-imaging codes. The images are
consistent and show a cool extended spot, symmetric about the pole, at
a temperature approximately 750K below the average photospheric value.
Smaller cool spots are found fairly uniformly distributed at latitudes
below the polar cap with temperatures about 450K below the average
photospheric temperature. Resolution on the stellar surface is limited
to about 7° of arc, so structure within these spots is not
visible. Also at lower latitudes are hotter features with temperatures
up to 1000K above the photosphere. A trial Doppler image using a TiO
molecular feature reproduced the cool polar cap at a temperature about
100K below the value from the atomic line images. The equatorial
features, however, were not properly reproduced since Doppler imaging
relies on information in the wings of lines for reconstructing
equatorial features, and for V410 Tau these molecular band lines
overlap. In 1993, V410 Tau had a large photometric amplitude resulting
from the concentration of cool spots on the hemisphere of the star
visible at phase 0°, a phenomenon known as preferred longitude. In
contrast, the small photometric amplitude observed currently is due to
a strong symmetric polar spot and the uniform distribution in
longitude of equatorial cool and warm spots. This redistribution of
surface features may be the beginning of a slow "flip-flop" for V410
Tau where spot locations alternate between preferred longitudes. Flare
events linked to two of the hotter spots in the Doppler image were
observed.
Description:
High-resolution spectroscopic observations were obtained with the
ESPADONS echelle spectrograph and polarimeter in Stokes I and V at the
3.6m CFHT on Mauna Kea, Hawaii. Data were obtained in queue mode
during one observing block over four nights from 2008 October 15 to
19, and one over 13 nights distributed between the dates of 2008
December 5 to 2009 January 14. A spectral resolution of 60000 with a
useful wavelength coverage of 390-900nm was obtained.
Photoelectric photometry of V410 Tau was obtained with the University
of Vienna 0.75m twin automatic photoelectric telescopes (APTs) at the
Fairborn Observatory in southern Arizona. The T7-APT used
Johnson-Cousins VIC filters and observed from JD 2450395 in 1996
through 2454892 in 2009.
Objects:
---------------------------------------------------
RA (2000) DE Designation(s)
---------------------------------------------------
04 18 31.11 +28 27 16.1 V* V410 Tau = HD 283518
---------------------------------------------------
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table1.dat 30 1588 Photometry of V410 Tau used in preparing Figure 1
--------------------------------------------------------------------------------
See also:
B/cfht : Log of CFHT Exposures (CADC, 1979-)
J/A+A/479/827 : UBVR light curves of weak-line T Tauri stars (Grankin+, 2008)
Byte-by-byte Description of file: table1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 13 F13.5 d HJD Heliocentric Julian Date of observation
15- 22 F8.5 mag DVmag Differential V band magnitude
24- 30 F7.5 mag e_DVmag RMS of DVmag
--------------------------------------------------------------------------------
History:
From electronic version of the journal
(End) Greg Schwarz [AAS], Emmanuelle Perret [CDS] 05-Sep-2012