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Author (up) Kirk, J.; Rackham, B.V.; MacDonald, R.J.; Lopez-Morales, M.; Espinoza, N.; Lendl, M.; Wilson, J.; D.J.; Wheatley, P.J.; Skillen, I.; Apai, D.; Bixel, A.; Gibson, N.P.; Jordan, A.; Lewis, N.K.; Louden, T.; McGruder, C.D.; Nikolov, N.; Rodler, F.; Weaver, I.C.
Title ACCESS and LRG-BEASTS: A Precise New Optical Transmission Spectrum of the Ultrahot Jupiter WASP-103b Type
Year 2021 Publication Astronomical Journal Abbreviated Journal Astron. J.
Volume 162 Issue 1 Pages 34
Keywords GAS-GIANT EXOPLANET; HOT JUPITERS; ATMOSPHERES; TRANSIT; PLANET; EFFICIENT; SPECTROSCOPY; RETRIEVAL; CHEMISTRY; EXPLAIN
Abstract We present a new ground-based optical transmission spectrum of the ultrahot Jupiter WASP-103b (Teq=2484
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0004-6256 ISBN Medium
Area Expedition Conference
Notes WOS:000667942900001 Approved
Call Number UAI @ alexi.delcanto @ Serial 1434
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Author (up) McGruder, C.D.; Lopez-Morales, M.; Espinoza, N.; Rackham, B.V.; Apai, D.; Jordan, A.; Osip, D.J.; Alam, M.K.; Bixel, A.; Fortney, J.J.; Henry, G.W.; Kirk, J.; Lewis, N.K.; Rodler, F.; Weaver, I.C.
Title ACCESS: Confirmation of No Potassium in the Atmosphere of WASP-31b Type
Year 2020 Publication Astronomical Journal Abbreviated Journal Astron. J.
Volume 160 Issue 5 Pages 22 pp
Keywords
Abstract We present a new optical (400-950 nm) transmission spectrum of the hot Jupiter WASP-31b (M = 0.48 M-J; R = 1.54 R-J; P = 3.41 days), obtained by combining four transit observations. These transits were observed with IMACS on the Magellan Baade Telescope at Las Campanas Observatory as part of the ACCESS project. We investigate the presence of clouds/hazes in the upper atmosphere of this planet, as well as the contribution of stellar activity on the observed features. In addition, we search for absorption features of the alkali elements Na i and K i, with particular focus on K i, for which there have been two previously published disagreeing results. Observations with Hubble Space Telescope (HST)/STIS detected K i, whereas ground-based low- and high-resolution observations did not. We use equilibrium and nonequilibrium chemistry retrievals to explore the planetary and stellar parameter space of the system with our optical data combined with existing near-IR observations. Our best-fit model is that with a scattering slope consistent with a Rayleigh slope (alpha = 5(-3.1)(+2.9)), high-altitude clouds at a log cloud top pressure of -3.6(-2.1)(+2.7) bars, and possible muted H2O features. We find that our observations support other ground-based claims of no K I. Clouds are likely why signals like H2O are extremely muted and Na or K cannot be detected. We then juxtapose our Magellan/IMACS transmission spectrum with existing VLT/FORS2, HST/WFC3, HST/STIS, and Spitzer observations to further constrain the optical-to-infrared atmospheric features of the planet. We find that a steeper scattering slope (alpha = 8.3 +/- 1.5) is anchored by STIS wavelengths blueward of 400 nm and only the original STIS observations show significant potassium signal.
Address [McGruder, Chima D.; Lopez-Morales, Mercedes; Alam, Munazza K.; Kirk, James; Weaver, Ian C.] Harvard & Smithsonian, Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA, Email: chima.mcgruder@cfa.harvard.edu
Corporate Author Thesis
Publisher Iop Publishing Ltd Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0004-6256 ISBN Medium
Area Expedition Conference
Notes WOS:000584919200001 Approved
Call Number UAI @ alexi.delcanto @ Serial 1262
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Author (up) Weaver, I.C.; Lopez-Morales, M.; Espinoza, N.; Rackham, B.V.; Osip, D.J.; Apai, D.; Jordan, A.; Bixel, A.; Lewis, N.K.; Alam, M.K.; Kirk, J.; McGruder, C.; Rodler, F.; Fienco, J.
Title ACCESS: A Visual to Near-infrared Spectrum of the Hot Jupiter WASP-43b with Evidence of H2O, but No Evidence of Na or K Type
Year 2020 Publication Astronomical Journal Abbreviated Journal Astron. J.
Volume 159 Issue 1 Pages 21 pp
Keywords
Abstract We present a new ground-based visual transmission spectrum of the hot Jupiter WASP-43b, obtained as part of the ACCESS Survey. The spectrum was derived from four transits observed between 2015 and 2018, with combined wavelength coverage between 5300 and 9000 A and an average photometric precision of 708 ppm in 230 A bins. We perform an atmospheric retrieval of our transmission spectrum combined with literature Hubble Space Telescope/WFC3 observations to search for the presence of clouds/hazes as well as Na, K, H alpha, and H2O planetary absorption and stellar spot contamination over a combined spectral range of 5318-16420 A. We do not detect a statistically significant presence of Na i or K i alkali lines, or H alpha in the atmosphere of WASP-43b. We find that the observed transmission spectrum can be best explained by a combination of heterogeneities on the photosphere of the host star and a clear planetary atmosphere with H2O. This model yields a log evidence of 8.26 0.42 higher than a flat (featureless) spectrum. In particular, the observations marginally favor the presence of large, low-contrast spots over the four ACCESS transit epochs with an average covering fraction T = 132 K 132 K. Within the planet's atmosphere, we recover a log H2O volume mixing ratio of -2.78(-1.47)(+1.38), which is consistent with previous H2O abundance determinations for this planet.
Address [Weaver, Ian C.; Lopez-Morales, Mercedes; Alam, Munazza K.; Kirk, James; McGruder, Chima] Harvard & Smithsonian, Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA, Email: iweaver@cfa.harvard.edu
Corporate Author Thesis
Publisher Iop Publishing Ltd Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0004-6256 ISBN Medium
Area Expedition Conference
Notes WOS:000519136000001 Approved
Call Number UAI @ eduardo.moreno @ Serial 1168
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Author (up) Yan, F.; Espinoza, N.; Molaverdikhani, K.; Henning, T.; Mancini, L.; Mallonn, M.; Rackham, B.V.; Apai, D.; Jordan, A.; Molliere, P.; Chen, G.; Carone, L.; Reiners, A.
Title LBT transmission spectroscopy of HAT-P-12b: Confirmation of a cloudy atmosphere with no significant alkali features Type
Year 2020 Publication Astronomy & Astrophysics Abbreviated Journal Astron. Astrophys.
Volume 642 Issue Pages 13 pp
Keywords planets and satellites: atmospheres; techniques: spectroscopic; stars: atmospheres; planets and satellites: individual: HAT-P-12b
Abstract The hot sub-Saturn-mass exoplanet HAT-P-12b is an ideal target for transmission spectroscopy because of its inflated radius. We observed one transit of the planet with the multi-object double spectrograph (MODS) on the Large Binocular Telescope (LBT) with the binocular mode and obtained an atmosphere transmission spectrum with a wavelength coverage of similar to 0.4-0.9 μm. The spectrum is relatively flat and does not show any significant sodium or potassium absorption features. Our result is consistent with the revised Hubble Space Telescope (HST) transmission spectrum of a previous work, except that the HST result indicates a tentative detection of potassium. The potassium discrepancy could be the result of statistical fluctuation of the HST dataset. We fit the planetary transmission spectrum with an extensive grid of cloudy models and confirm the presence of high-altitude clouds in the planetary atmosphere. The fit was performed on the combined LBT and HST spectrum, which has an overall wavelength range of 0.4-1.6 μm. The LBT/MODS spectrograph has unique advantages in transmission spectroscopy observations because it can cover a wide wavelength range with a single exposure and acquire two sets of independent spectra simultaneously.
Address [Yan, F.; Reiners, A.] Georg August Univ, Inst Astrophys, Friedrich Hund Pl 1, D-37077 Gottingen, Germany, Email: fei.yan@uni-goettingen.de
Corporate Author Thesis
Publisher Edp Sciences S A Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1432-0746 ISBN Medium
Area Expedition Conference
Notes WOS:000581918600001 Approved
Call Number UAI @ alexi.delcanto @ Serial 1237
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