J/ApJ/898/21 Spitzer/IRAC obs. of HD113766 & HD172555 systems (Su+, 2020)
Mid-infrared studies of HD 113766 and HD 172555: assessing variability in the
terrestrial zone of young exoplanetary systems.
Su K.Y.L., Rieke G.H., Melis C., Jackson A.P., Smith P.S., Meng H.Y.A.,
Gaspar A.
<Astrophys. J., 898, 21 (2020)>
=2020ApJ...898...21S 2020ApJ...898...21S
ADC_Keywords: Photometry, infrared; Stars, double and multiple;
Stars, early-type
Keywords: Circumstellar matter ; Debris disks ; Exozodiacal dust ;
Infrared excess ; Early-type stars ; Extrasolar rocky planets
Abstract:
We present multiepoch infrared photometry and spectroscopy obtained
with warm Spitzer, Subaru, and the Stratospheric Observatory for
Infrared Astronomy to assess variability for the young (∼20Myr) and
dusty debris systems around HD 172555 and HD 113766A. No variations
(within 0.5%) were found for the former at either 3.6 or 4.5µm,
while significant nonperiodic variations (peak to peak of ∼10%-15%
relative to the primary star) were detected for the latter. Relative
to the Spitzer Infrared Spectrograph spectra taken in 2004, multiepoch
mid-infrared spectra reveal no change in either the shape of the
prominent 10µm solid-state features or the overall flux levels (no
more than 20%) for both systems, corroborating the fact that the
population of submicron-size grains that produce the pronounced
solid-state features is stable over a decadal timescale. We suggest
that these submicron-size grains were initially generated in an
optically thick clump of debris of millimeter-size vapor condensates
resulting from a recent violent impact between large asteroidal or
planetary bodies. Because of the shielding from the stellar photons
provided by this clump, intense collisions led to an overproduction of
fine grains that would otherwise be ejected from the system by
radiation pressure. As the clump is sheared by its orbital motion and
becomes optically thin, a population of very fine grains could remain
in stable orbits until Poynting-Robertson drag slowly spirals them
into the star. We further suggest that the 3-5µm disk variation
around HD 113766A is consistent with a clump/arc of such fine grains
on a modestly eccentric orbit in its terrestrial zone.
Description:
Multiple Infrared Array Camera (IRAC) 3.6 and 4.5um observations were
obtained during the Spitzer warm mission, resulting in a total of
11 Astronomical Observation Requests (AORs) for HD 172555 from
PID 90250 (PI: Stapelfeldt) and 11093 (PI: Su), and 67 AORs for
HD113766 from PID 11093.
Both objects have two Spitzer visibility windows per year with each
having a length of ∼46-52 days. Various observation cadences were used
to search for flux variability. A cadence of 10±2 days was used for
HD 172555 under PID 11093 for both visibility windows in 2016, where
the flux can be compared to the one obtained in 2013 under PID 90250.
For HD 113766, 5+/2 and 15±2 days were used in individual visibility
windows.
Objects:
------------------------------------------------------------
RA (ICRS) DE Designation(s)
------------------------------------------------------------
13 06 35.84 -46 02 02.0 HD 113766 = WDS J13066-4602AB
18 45 26.90 -64 52 16.5 HD 172555 = WDS J18454-6452A
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
tablea1.dat 92 67 The IRAC fluxes of the HD 113766 system
tablea2.dat 77 11 The IRAC fluxes of the HD 172555 system
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See also:
II/328 : AllWISE Data Release (Cutri+ 2013)
I/345 : Gaia DR2 (Gaia Collaboration, 2018)
J/A+A/356/141 : BV photometry for components of HIP doubles (Fabricius+ 2000)
J/A+A/460/695 : Search for Associations Containing Young stars (Torres+, 2006)
J/AJ/135/2245 : Absolute spectrum of Sun & Vega for 0.2-30um (Rieke+, 2008)
J/ApJ/698/1989 : Spitzer survey of NGC 2451 (Balog+, 2009)
J/ApJ/705/89 : IRS spectra of solar-type stars (Lawler+, 2009)
J/ApJ/738/122 : ScoCen debris disks Around F- and G-type stars (Chen+, 2011)
J/ApJ/746/154 : Improved parallaxes for Sco-Cen members (Pecaut+, 2012)
J/ApJ/785/33 : High quality Spitzer/MIPS obs. of F-K stars (Sierchio+, 2014)
J/ApJ/805/77 : Spitzer 3.6 and 4.5um monitoring of 5 stars (Meng+, 2015)
J/ApJ/798/87 : Spitzer/IRS debris disk catalog. II. (Mittal+, 2015)
J/ApJ/845/120 : Spitzer obs. of warm dust in debris disks (Ballering+, 2017)
J/ApJ/836/34 : 24um excesses & membership of NGC2244 (Meng+, 2017)
J/A+A/618/A151 : HD 172555 polarimetric images (Engler+, 2018)
J/AJ/157/202 : IRAC fluxes of the ID8 and P1121 systems (Su+, 2019)
Byte-by-byte Description of file: tablea[12].dat
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Bytes Format Units Label Explanations
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1- 8 I8 --- AORKEY [48318464/61718528] Spizter AOR Key
10- 21 F12.6 d BMJD3.6 [56455.2/58450.2] Barycentric Modified Julian
Date, 3.6um obs (JD-2400000.5)
23- 30 F8.3 mJy F3.6 [772/5385] Spitzer/IRAC Band 1 (3.6um) flux
(including star)
32- 36 F5.3 mJy e_F3.6 [0.6/6.1] Uncertainty in Flux-3.6
38- 43 F6.3 mJy EF3.6 [44/87]? Excess flux (excluding star)
45- 50 F6.3 mJy e_EF3.6 [11/12.5]? Uncertainty in excFlux-3.6
52- 63 F12.6 d BMJD4.5 [57128.5/58450.2]? Barycentric Modified Julian
Date, 4.5um obs (JD-2400000.5)
65- 72 F8.3 mJy F4.5 [639/3510.5]? Spitzer/IRAC Band 2 (4.5um) flux
(including star)
74- 78 F5.3 mJy e_F4.5 [0.7/3.4]? Uncertainty in Flux-4.5
80- 86 F7.3 mJy EF4.5 [183/236]? Excess flux (excluding star)
88- 92 F5.3 mJy e_EF4.5 [6.8/7.7]? Uncertainty in excFlux-4.5
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History:
From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 04-Nov-2021