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. =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 CH_4_{nu}_3_ fluorescence. We do not detect a similar bright 3.3 {mu}m feature to ~3{sigma}, 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 1{sigma} 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), 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: ---------------------------------------------------------- RA (ICRS) DE Designation(s) ---------------------------------------------------------- 22 03 10.77 +18 53 03.5 HD 209458b = NAME Osiris ---------------------------------------------------------- File Summary: -------------------------------------------------------------------------------- FileName Lrecl Records Explanations -------------------------------------------------------------------------------- ReadMe 80 . This file table4.dat 67 194 Potential exoplanet targets for measuring the primary transit with Palomar/TripleSpec -------------------------------------------------------------------------------- See also: II/313 : Palomar Transient Factory (PTF) photometric catalog 1.0 (Ofek+, 2012) Byte-by-byte Description of file: table4.dat -------------------------------------------------------------------------------- Bytes Format Units Label Explanations -------------------------------------------------------------------------------- 1- 13 A13 --- ID Exoplanet identifier 15- 22 F8.5 mag Ksmag The K_s_ 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 -------------------------------------------------------------------------------- Note (1): Calculated by assuming a H_2_-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 =[(R_p_+5*H)/R_s_]^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 K_s_-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 K_s_ magnitudes. -------------------------------------------------------------------------------- History: From electronic version of the journal ================================================================================ (End) Prepared by [AAS], Tiphaine Pouvreau [CDS] 31-May-2017