J/AJ/150/32 KELT 2006-2013 photometry of V409 Tau and AA Tau (Rodriguez+, 2015)
V409 Tau as another AA Tau: photometric observations of stellar occultations by
the circumstellar disk.
Rodriguez J.E., Pepper J., Stassun K.G., Siverd R.J., Cargile P.,
Weintraub D.A., Beatty T.G., Gaudi B.S., Mamajek E.E., Sanchez N.N.
<Astron. J., 150, 32 (2015)>
=2015AJ....150...32R 2015AJ....150...32R
ADC_Keywords: YSOs ; Stars, pre-main sequence ; Stars, variable ; Photometry
Keywords: circumstellar matter - protoplanetary disks -
stars: individual: (V409 Tau,AA Tau) - stars: pre-main sequence -
stars: variables: T Tauri, Herbig Ae/Be
Abstract:
AA Tau is a well studied young stellar object (YSO) that presents many
of the photometric characteristics of a Classical T Tauri star (CTTS),
including short-timescale stochastic variability attributed to spots
and/or accretion as well as long-duration dimming events attributed to
occultations by vertical features (e.g., warps) in its circumstellar
disk. We present new photometric observations of AA Tau from the
Kilodegree Extremely Little Telescope North (KELT-North) which reveal
a deep, extended dimming event in 2011, which we show supports the
interpretation by Bouvier et al. of an occultation by a high-density
feature in the circumstellar disk located >8AU from the star. We also
present KELT-North observations of V409 Tau, a relatively unstudied
YSO also in Taurus-Auriga, showing short timescale erratic
variability, along with two separate long and deep dimming events, one
from 2009 January through late 2010 October, and the other from 2012
March until at least 2013 September. We interpret both dimming events
to have lasted more than 600 days, each with a depth of ∼1.4mag. From
a spectral energy distribution analysis, we propose that V409 Tau is
most likely surrounded by a circumstellar disk viewed nearly edge-on,
and using Keplerian timescale arguments we interpret the deep dimmings
of V409 Tau as occultations from one or more features within this disk
≳10AU from the star. In both AA Tau and V409 Tau, the usual CTTS
short-timescale variations associated with accretion processes close
to the stars continue during the occultations, further supporting the
distant occulting material interpretation. Like AA Tau, V409 Tau
serves as a laboratory for studying the detailed structure of the
protoplanetary environments of T Tauri disks, specifically disk
structures that may be signposts of planet formation at many AU out in
the disk. We also provide a table of all currently known
disk-occulting young stars as a convenient reference for future work
on such objects.
Description:
The Kilodegree Extremely Little Telescope (KELT) project is an
ongoing, wide-field (26°*26°) survey for transiting planets
around bright stars (V=8-10). The survey uses two telescopes,
KELT-South (Sutherland, South Africa) and KELT-North (Sonita,
Arizona), and observe in a broad R-band filter, with a ∼15minute
cadence and a typical photometric precision for stars of V∼11 of
∼0.04mag (Pepper et al., 2007PASP..119..923P 2007PASP..119..923P, 2012PASP..124..230P 2012PASP..124..230P).
V409 Tau and AA Tau are both located in KELT-North Field 03, which is
centered on α=3h58m12s, δ=59°32'24''. All of our
KELT observations come from the KELT-North telescope. KELT-North
observed this field for 7 seasons from UT 2006 October 26 to UT 2013
January 9 (2006 Oct 26--2007 Jan 17, 2007 Sep 19--2008 Feb 2, 2008 Sep
24--2009 Mar 26, 2009 Sep 22--2010 Mar 16, 2010 Oct 2--2011 Mar 17,
2011 Sep 22--2012 Mar 21, 2012 Sep 17--2013 Jan 9), obtaining ∼9100
images. All data shown has a relative photometric error less than 20%
rms.
Objects:
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RA (ICRS) DE Designation(s) (Period)
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04 34 55.42 +24 28 53.2 V* AA Tau = GSC 01833-00851 (P=8.21)
04 18 10.79 +25 19 57.4 V* V409 Tau = GSC 01819-01472 (P=4.737)
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table3.dat 36 17972 KELT-North photometric observations of V409 Tau
and AA Tau
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See also:
J/AJ/146/112 : V light curve of RW Aur (Rodriguez+, 2013)
J/A+A/557/A77 : VR light curves of AA Tau in 2007-2013 (Bouvier+, 2013)
J/ApJ/771/129 : Submillimetric Class II sources of Taurus (Andrews+, 2013)
J/A+A/463/1017 : B and V light curves of AA Tau (Bouvier+, 2007)
J/A+A/409/169 : UBVRI light curves of AA Tau in 1999 (Bouvier+, 2003)
J/A+A/349/619 : UBVRI light curves of AA Tau in 1995 (Bouvier+, 1999)
Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 8 A8 --- Name Stellar name (AA Tau or V409 Tau)
10- 23 F14.6 d JD Julian Date of the observation (Terrestrial time)
25- 30 F6.3 mag mag [-4.852/3.299] Relative KELT-North instrumental
magnitude (1)
32- 36 F5.3 mag e_mag [0.002/1.158] Photometric error in mag (2)
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Note (1): The median of the KELT-North instrumental magnitude has been
subtracted off.
Note (2): True per-point magnitude errors must fold in 0.036mag systematic
errors.
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History:
From electronic version of the journal
(End) Greg Schwarz [AAS], Sylvain Guehenneux [CDS] 23-Jul-2015