J/ApJ/743/85 IRS multi-epoch observations of HD 69830 (Beichman+, 2011)
Multi-epoch observations of HD 69830: high-resolution spectroscopy and limits
to variability.
Beichman C.A., Lisse C.M., Tanner A.M., Bryden G., Akeson R.L.,
Ciardi D.R., Boden A.F., Dodson-Robinson S.E., Salyk C., Wyatt M.C.
<Astrophys. J., 743, 85 (2011)>
=2011ApJ...743...85B 2011ApJ...743...85B
ADC_Keywords: Stars, double and multiple ; Spectra, infrared
Keywords: infrared: planetary systems - Kuiper belt: general - zodiacal dust -
planets and satellites: dynamical evolution and stability -
planet-disk interactions - stars: individual (HD 69830)
Abstract:
The main-sequence solar-type star HD 69830 has an unusually large
amount of dusty debris orbiting close to three planets found via the
radial velocity technique. In order to explore the dynamical
interaction between the dust and planets, we have performed
multi-epoch photometry and spectroscopy of the system over several
orbits of the outer dust. We find no evidence for changes in either
the dust amount or its composition, with upper limits of 5%-7%
(1σ per spectral element) on the variability of the dust
spectrum over 1 year, 3.3% (1σ) on the broadband disk emission
over 4 years, and 33% (1σ) on the broadband disk emission over
24 years. Detailed modeling of the spectrum of the emitting dust
indicates that the dust is located outside of the orbits of the three
planets and has a composition similar to main-belt, C-type asteroids
in our solar system. Additionally, we find no evidence for a wide
variety of gas species associated with the dust. Our new higher
signal-to-noise spectra do not confirm our previously claimed
detection of H2O ice leading to a firm conclusion that the debris
can be associated with the break-up of one or more C-type asteroids
formed in the dry, inner regions of the protoplanetary disk of the HD
69830 system. The modeling of the spectral energy distribution and
high spatial resolution observations in the mid-infrared are
consistent with a ∼1 AU location for the emitting material.
Description:
Observations were made of HD 69830 using all three Spitzer instruments:
the IRAC and MIPS cameras and the Infrared Spectrograph (IRS). In
addition to discovery data obtained with MIPS and IRS in 2004, the two
photometric instruments were used at one epoch in 2007 while the IRS
spectrometer was used on five occasions at low resolution (2007 Dec
20, 2008 Apr 30, 2008 Dec 5, 2009 Jan 9 & 15) and six occasions at
high resolution. All observations are from program PID40109; except
2009 Jan 9 & 15 from PID528.
Objects:
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RA (2000) DE Designation(s)
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08 18 23.95 -12 37 55.8 HD 69830 = TYC 5435-2991-1
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table4.dat 51 272 Spitzer/IRS low resolution spectrum
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See also:
I/239 : The Hipparcos and Tycho Catalogues (ESA 1997)
J/A+A/521/A12 : RVs of nearby late-type stars (Maldonado+, 2010)
J/ApJ/705/1226 : Planet-bearing stars in Spitzer (Bryden+, 2009)
J/ApJ/705/89 : IRS spectra of solar-type stars (Lawler+, 2009)
J/ApJ/700/L73 : Photospheric fluxes at 24 and 70µm (Kospal+, 2009)
J/ApJ/687/1264 : Age estimation for solar-type dwarfs (Mamajek+, 2008)
J/ApJ/636/1098 : Debris disks around solar-type stars (Bryden+, 2006)
J/ApJ/620/1010 : Spitzer 24µm photometry of A dwarfs (Rieke+, 2005)
J/ApJS/151/387 : NIR spectral library of late-type stars (Ivanov+, 2004)
J/A+AS/121/139 : UMIST database. 1995 (Millar+, 1997)
Byte-by-byte Description of file: table4.dat
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Bytes Format Units Label Explanations
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1- 6 F6.3 um lambda [7.5/35] Wavelength λ (microns)
8- 13 F6.1 mJy Flux [101/1560] Observed flux density
15- 18 F4.1 mJy e_Flux [0.7/55] Uncertainty in Flux (1)
20- 25 F6.1 mJy Phot Flux density from photosphere
27- 31 F5.1 mJy Exc [-0.1/123] Flux density from excess
33- 36 F4.1 mJy e_Exc [0.7/55] Uncertainty in Exc
38- 44 F7.4 --- Frac Fractional excess
46- 51 F6.4 --- e_Frac Uncertainty in Frac
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Note (1): Stated uncertainties are the larger of 1) standard deviation of the
mean of three individual repeats or 2) the average of the three noise
values from the individual repeats divided by (3-1)0.5. No
systematic error for the subtraction of the photospheric model has
been applied.
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History:
From electronic version of the journal
(End) Greg Schwarz [AAS], Emmanuelle Perret [CDS] 06-May-2013