J/AJ/159/204 HAT-P-41b transmission spectra with HST WFC3/UVIS (Wakeford+, 2020)
Into the UV: a precise transmission spectrum of HAT-P-41b using Hubble's
WFC3/UVIS G280 Grism.
Wakeford H.R., Sing D.K., Stevenson K.B., Lewis N.K., Pirzkal N.,
Wilson T.J., Goyal J., Kataria T., Mikal-Evans T., Nikolov N., Spake J.
<Astron. J., 159, 204 (2020)>
=2020AJ....159..204W 2020AJ....159..204W
ADC_Keywords: Exoplanets; Spectra, optical; Spectra, ultraviolet;
Stars, atmospheres
Keywords: Exoplanet atmospheres ; Near ultraviolet astronomy ;
Hubble Space Telescope
Abstract:
The ultraviolet-visible wavelength range holds critical spectral
diagnostics for the chemistry and physics at work in planetary
atmospheres. To date, time-series studies of exoplanets to
characterize their atmospheres have relied on several combinations of
modes on the Hubble Space Telescope's STIS/COS instruments to access
this wavelength regime. Here for the first time, we apply the Hubble
WFC3/UVIS G280 grism mode to obtain exoplanet spectroscopy from 200 to
800nm in a single observation. We test the G280 grism mode on the hot
Jupiter HAT-P-41b over two consecutive transits to determine its
viability for the characterization of exoplanet atmospheres. We obtain
a broadband transit depth precision of 29-33ppm and a precision of on
average 200ppm in 10nm spectroscopic bins. Spectral information from
the G280 grism can be extracted from both the positive and negative
first-order spectra, resulting in a 60% increase in the measurable
flux. Additionally, the first Hubble Space Telescope orbit can be
fully utilized in the time-series analysis. We present detailed
extraction and reduction methods for use by future investigations with
this mode, testing multiple techniques. We find the results to be
fully consistent with STIS measurements of HAT-P-41b from 310 to
800nm, with the G280 results representing a more observationally
efficient and precise spectrum. HAT-P-41b's transmission spectrum is
best fit with a model with Teq=2091K, high metallicity, and
significant scattering and cloud opacity. With these
first-of-their-kind observations, we demonstrate that WFC3/UVIS G280
is a powerful new tool to obtain UV-optical spectra of exoplanet
atmospheres, adding to the UV legacy of Hubble and complementing
future observations with the James Webb Space Telescope.
Description:
We used Hubble Space Telescope (HST) Wild Field Camera 3 (WFC3/UVIS)
channel with the G280 spectroscopic slitless grism to observe the
spectrum of the transiting exoplanet host star HAT-P-41 from 200 to
800nm (GO-15288, PIs D.K. Sing & N.K. Lewis). We observed the target
HAT-P-41, over two visits, each consisting of five HST orbits, to
measure the transit of the hot Jupiter exoplanet HAT-P-41b. The two
visits were separated by a single planetary orbital period (visit 1:
2018-August-1; visit 2: 2018-August-4, period = 2.694047days). Each
visit consists of 54 exposures, over five HST orbits, with exposure
times of 190s.
Objects:
-------------------------------------------------------------
RA (2000) DE Designation(s) (Period)
-------------------------------------------------------------
19 49 17.44 +04 40 20.8 HAT-P-41b = HAT-P-41b (P=2.694047)
-------------------------------------------------------------
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table3.dat 70 59 Transmission spectrum of HAT-P-41b
--------------------------------------------------------------------------------
See also:
VI/156 : M-dwarf Lum-Temp-Radius relationships (Morrell+, 2019)
J/ApJ/747/35 : HST/WFC3 transit observation of GJ1214b (Berta+, 2012)
J/AJ/144/139 : HAT-P-39, HAT-P-40, and HAT-P-41 follow-up (Hartman+, 2012)
J/ApJ/754/136 : Light curves of HD 149026b in 3.6-16um (Stevenson+, 2012)
J/A+A/563/A41 : WASP-43 OSIRIS transmission spectroscopy (Murgas+, 2014)
J/ApJ/791/55 : HD 189733b in transit light curve (McCullough+, 2014)
J/A+A/573/A90 : STAGGER-grid of 3D stellar models. IV. (Magic+, 2015)
J/MNRAS/446/2428 : WASP-31b:HST/Spitzer transmission spectral (Sing+, 2015)
J/A+A/587/A67 : WASP-49b FORS2 multi-epoch spectra (Lendl+, 2016)
J/A+A/590/A100 : Transmission spectroscopy of HAT-P-32b (Mallonn+, 2016)
J/A+A/596/A47 : FORS2 transmission spectra of WASP-17b (Sedaghati+, 2016)
J/A+A/602/A107 : 231 transiting planets eccentricity and mass (Bonomo+, 2017)
J/AJ/155/66 : Stroemgren photometric obs. of GJ 436b (Lothringer+, 2018)
J/AJ/156/178 : NIR transm. spectra of TRAPPIST-1 planets (Zhang+, 2018)
J/A+A/627/A165 : KELT-9 b atmos. model transm. spectra (Hoeijmakers+, 2019)
J/A+A/628/A9 : MASCARA-2b transmission spectra (Casasayas-Barris+, 2019)
J/AJ/159/239 : Transmission Spectroscopy Metric of exoplanets (Guo+, 2020)
Byte-by-byte Description of file: table3.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 3 I3 nm lambda [205/785] Wavelength
5- 11 F7.5 % DepthSM [0.92/1.2] Transit depth, systematic
marginalization
13- 19 F7.5 % e_DepthSM [0.008/0.2] Error on DepthSM
21- 27 F7.5 % DepthJD [0.85/1.2] Transit depth, jitter decorrelation
29- 35 F7.5 % e_DepthJD [0.01/0.2] Error on DepthJD
37- 43 F7.5 --- c1 [0.26/0.96] Limb-darkening coefficients c1 (1)
45- 52 F8.5 --- c2 [-1.32/0.84] Limb-darkening coefficients c2 (1)
54- 61 F8.5 --- c3 [-0.48/2.4] Limb-darkening coefficients c3 (1)
63- 70 F8.5 --- c4 [-0.83/0.82] Limb-darkening coefficients c4 (1)
--------------------------------------------------------------------------------
Note (1): Based on using the +1 order throughput curve and 3D stellar
models from Magic+, 2015, J/A+A/573/A90.
--------------------------------------------------------------------------------
History:
From electronic version of the journal
(End) Prepared by Coralie Fix [CDS], 24-Sep-2020