J/AJ/160/188ivo://CDS.VizieR/J/AJ/160/188doi:10.26093/cds/vizier.51600188CDSDiamond-Lowe H.Charbonneau D.Malik M.Kempton E.M.-R.Beletsky Y.2021-07-05T07:22:43Z2020-12-22T08:58:45ZCDS support team

CDS, Observatoire de Strasbourg, 11 rue de l'Universite, F-67000 Strasbourg, France

cds-question@unistra.frexoplanetsbrown-dwarfsvisible-astronomyspectroscopyinfrared-astronomyAtmospheric studies of spectroscopically accessible terrestrial exoplanets lay the groundwork for comparative planetology between these worlds and the solar system terrestrial planets. LHS3844b is a highly irradiated terrestrial exoplanet (R=1.303{+/-}0.022R{Earth}) orbiting a mid-M dwarf 15parsecs away. Work based on near-infrared Spitzer phase curves ruled out atmospheres with surface pressures >~10bars on this planet. We present 13 transit observations of LHS3844b taken with the Magellan Clay telescope and the LDSS3C multi-object spectrograph covering 620-1020nm. We analyze each of the 13 data sets individually using a Gaussian process regression, and present both white and spectroscopic light curves. In the combined white light curve we achieve an rms precision of 65ppm when binning to 10minutes. The mean white light-curve value of (Rp/Rs)^2^ is 0.4170{+/-}0.0046%. To construct the transmission spectrum, we split the white light curves into 20 spectrophotometric bands, each spanning 20nm, and compute the mean values of (Rp/Rs)^2^ in each band. We compare the transmission spectrum to two sets of atmospheric models. We disfavor a clear, solar composition atmosphere ({mu}=2.34) with surface pressures >~0.1bar to 5.2{sigma} confidence. We disfavor a clear, H2O steam atmosphere ({mu}=18) with surface pressures >~0.1bar to low confidence (2.9{sigma}). Our observed transmission spectrum favors a flat line. For solar composition atmospheres with surface pressures >~1bar we rule out clouds with cloud-top pressures of 0.1bar (5.3{sigma}), but we cannot address high-altitude clouds at lower pressures. Our results add further evidence that LHS3844b is devoid of an atmosphere.2020AJ....160..188Dhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/AJ/160/188CatalogResearchIsServedByTAP VizieR generic servicerelated-toJ/A+A/537/L2 : Transmission spectrum of Venus (Ehrenreich+, 2012)J/A+A/563/A41 : WASP-43 OSIRIS transmission spectroscopy (Murgas+, 2014)J/ApJ/800/135 : HARPS-N radial velocities of KOI-69 (Dressing+, 2015)J/A+A/590/A100 : Transmission spectroscopy of HAT-P-32b (Mallonn+, 2016)J/A+A/596/A47 : FORS2 transmission spectroscopy of WASP-17b (Sedaghati+, 2016)J/A+A/605/L9 : NIR spectrum of exoplanet HIP 65426b (Chauvin+, 2017)J/AJ/154/109 : California-Kepler Survey III. Planet radii (Fulton+, 2017)J/AJ/156/18 : APOGEE DR14: companions of evolved stars (Price-Whelan+,2018)J/AJ/156/217 : Stellar properties for M dwarfs MEarth-South (Newton+, 2018)J/A+A/624/A49 : Spectra Earth-like planets around M-dwarfs (Wunderlich+, 2019)J/A+A/632/A69 : CaII transmission spectrum of WASP-33b & KELT-9b (Yan+, 2019)J/MNRAS/486/5867 : Simulated Transit depths of 12 Hot Jupiters (Singh+, 2019)J/A+A/633/A110 : K band spectrum of beta Pictoris b (GRAVITY+, 2020)J/A+A/634/A29 : Kepler-278 and Kepler-391 spectra (Jofre+, 2020)J/AJ/159/239 : Transmission Spectroscopy Metric of exoplanets (Guo+, 2020)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/AJ/160/188https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/AJ/160/188http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/AJ/160/188https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/AJ/160/188https://vizier.iucaa.in/viz-bin/votable?-source=J/AJ/160/188http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/AJ/160/188GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapOpticalInfrareddefaultJ/AJ/160/188/table5Spectroscopic transit depthsrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintLoWave[620/1000] Lower wavelength rangenminstr.bandwidthintHiWave[640/1020] Upper wavelength rangenminstr.bandwidthintMiWave[630/1010] Middle of wavelength rangenminstr.bandwidthintTD1[0.217/0.478] Transit depth of 1st observation%phot.flux.density;arith.ratiofloate_TD1[0.036/0.181] Uncertainty in TD1%stat.errorfloatTD2[0.147/0.528] Transit depth of 2nd observation%phot.flux.density;arith.ratiofloate_TD2[0.024/0.101] Uncertainty in TD2%stat.errorfloatTD3[0.28/0.504] Transit depth of 3rd observation%phot.flux.density;arith.ratiofloate_TD3[0.022/0.076] Uncertainty in TD3%stat.errorfloatTD4[0.362/0.431] Transit depth of 4th observation%phot.flux.density;arith.ratiofloate_TD4[0.014/0.046] Uncertainty in TD4%stat.errorfloatTD5[0.347/0.438] Transit depth of 5th observation%phot.flux.density;arith.ratiofloate_TD5[0.017/0.064] Uncertainty in TD5%stat.errorfloatTD6[0.359/0.454] Transit depth of 6th observation%phot.flux.density;arith.ratiofloate_TD6[0.016/0.099] Uncertainty in TD6%stat.errorfloatTD7[0.218/0.515] Transit depth of 7th observation%phot.flux.density;arith.ratiofloate_TD7[0.019/0.11] Uncertainty in TD7%stat.errorfloatTD8[0.375/0.466] Transit depth of 8th observation%phot.flux.density;arith.ratiofloate_TD8[0.013/0.057] Uncertainty in TD8%stat.errorfloatTD9[0.351/0.457] Transit depth of 9th observation%phot.flux.density;arith.ratiofloate_TD9[0.012/0.043] Uncertainty in TD9%stat.errorfloatTD10[0.383/0.478] Transit depth of 10th observation%phot.flux.density;arith.ratiofloate_TD10[0.014/0.045] Uncertainty in TD10%stat.errorfloatTD11[0.373/0.487] Transit depth of 11th observation%phot.flux.density;arith.ratiofloate_TD11[0.015/0.05] Uncertainty in TD11%stat.errorfloatTD12[0.325/0.566] Transit depth of 12th observation%phot.flux.density;arith.ratiofloate_TD12[0.028/0.14] Uncertainty in TD12%stat.errorfloatTD13[0.346/0.454] Transit depth of 13th observation%phot.flux.density;arith.ratiofloate_TD13[0.02/0.061] Uncertainty in TD13%stat.errorfloatTDMean[0.3901/0.4254] Inverse-variance weighted mean transit depth%phot.flux.density;arith.ratiofloate_TDMean[0.005/0.0174] Uncertainty in Mean%stat.errorfloatRMS[1099/5377] Root Mean Square of all 13 observations(10-6)stat.errorintNoise[1.5/1.79] Expected noise (1)stat.snr;instr.det.noisefloat