J/ApJ/796/48 Potential exoplanet targets with Palomar/TripleSpec (Zellem+, 2014)
The ground-based H-, K-, and L-band absolute emission spectra of HD 209458b.
Zellem R.T., Griffith C.A., Deroo P., Swain M.R., Waldmann I.P.
<Astrophys. J., 796, 48 (2014)>
=2014ApJ...796...48Z 2014ApJ...796...48Z (SIMBAD/NED BibCode)
ADC_Keywords: Stars, double and multiple ; Planets ; Photometry, infrared
Keywords: atmospheric effects - methods: numerical -
planets and satellites: general -
planets and satellites: individual: HD 209458b -
techniques: spectroscopic
Abstract:
Here we explore the capabilities of NASA's 3.0 m Infrared Telescope
Facility (IRTF) and SpeX spectrometer and the 5.08 m Hale telescope
with the TripleSpec spectrometer with near-infrared H-, K-, and L-band
measurements of HD 209458b's secondary eclipse. Our IRTF/SpeX data are
the first absolute L-band spectroscopic emission measurements of any
exoplanet other than the hot Jupiter HD 189733b. Previous measurements
of HD 189733b's L band indicate bright emission hypothesized to result
from non-LTE CH4ν3 fluorescence. We do not detect a similar
bright 3.3 µm feature to ∼3σ, suggesting that fluorescence does
not need to be invoked to explain HD 209458b's L-band measurements.
The validity of our observation and reduction techniques, which decrease
the flux variance by up to 2.8 orders of magnitude, is reinforced by
1σ agreement with existent Hubble/NICMOS and Spitzer/IRAC1
observations that overlap the H, K, and L bands, suggesting that both
IRTF/SpeX and Palomar/TripleSpec can measure an exoplanet's emission
with high precision.
Description:
We observed HD 209458b's emission with the 3.0 m NASA IRTF at the
Mauna Kea Observatory and SpeX (Rayner et al. 2003PASP..115..362R 2003PASP..115..362R), a
near-IR spectrometer with a wavelength coverage of 2.0-4.2 um (K and L
bands) and a resolution of R=2500, and with the 200 inch (5.08 m)
Hale Telescope at the Palomar Observatory and TripleSpec, a near-IR
spectrometer with a wavelength coverage of 1.0-2.4 um (J, H, and K bands)
and a resolution of R=2500-2700. While low-resolution spectroscopic
observations are incapable of observing the fine-scale structure of
the spectral lines, the SpeX and TripleSpec spectral channels can be
binned to increase the signal-to-noise ratio (S/N). We observed
HD 209458b's 2011 September 9 (UT) secondary eclipse for ∼8 hr,
resulting in 1210 exposures of 10 s each in an ABBA nodding sequence.
Objects:
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RA (ICRS) DE Designation(s)
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22 03 10.77 +18 53 03.5 HD 209458b = NAME Osiris
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table4.dat 67 194 Potential exoplanet targets for measuring
the primary transit with Palomar/TripleSpec
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See also:
II/313 : Palomar Transient Factory (PTF) photometric catalog 1.0 (Ofek+, 2012)
Byte-by-byte Description of file: table4.dat
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Bytes Format Units Label Explanations
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1- 13 A13 --- ID Exoplanet identifier
15- 22 F8.5 mag Ksmag The Ks band magnitude
24- 33 F10.5 km H Scale height (1)
35- 44 F10.7 10-3 Abs Estimated lightcurve depth (2)
46- 55 F10.7 10-3 e_Abs Uncertainty in Abs (3)
57- 67 F11.7 --- SNR Signal to Noise Ratio
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Note (1): Calculated by assuming a H2-dominated atmosphere and that the mean
atmospheric temperature is equal to the planet's equilibrium
temperature.
Note (2): During primary transit; assuming that the planet's atmosphere is
optically thick at 5 scale heights H, we estimate the primary transit
depth =[(Rp+5*H)/Rs]2; please note that the typical
channel-to-channel signal from a spectrum will be approximately a
factor 10-100 smaller than the total photometric Ks-band transit
depth calculated here.
Note (3): Scaled from the binned K-band uncertainty measured here for
HD 209458b (208 ppm) to each system using their respective
Ks magnitudes.
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History:
From electronic version of the journal
(End) Prepared by [AAS], Tiphaine Pouvreau [CDS] 31-May-2017