ACCESS: a featureless optical transmission spectrum for WASP-19b from Magellan/IMACS. Issue 2 (4th October 2018)
- Record Type:
- Journal Article
- Title:
- ACCESS: a featureless optical transmission spectrum for WASP-19b from Magellan/IMACS. Issue 2 (4th October 2018)
- Main Title:
- ACCESS: a featureless optical transmission spectrum for WASP-19b from Magellan/IMACS
- Authors:
- Espinoza, Néstor
Rackham, Benjamin V
Jordán, Andrés
Apai, Dániel
López-Morales, Mercedes
Osip, David J
Grimm, Simon L
Hoeijmakers, Jens
Wilson, Paul A
Bixel, Alex
McGruder, Chima
Rodler, Florian
Weaver, Ian
Lewis, Nikole K
Fortney, Jonathan J
Fraine, Jonathan - Abstract:
- ABSTRACT: The short-period (0.94-d) transiting exoplanet WASP-19b is an exceptional target for transmission spectroscopy studies, due to its relatively large atmospheric scale height (∼500 km) and equilibrium temperature (∼2100 K). Here, we report on six precise spectroscopic Magellan/IMACS observations, five of which target the full optical window from$0.45\hbox{ to }0.9\, \mu$ m and one targeting the$0.4\hbox{--}0.55\, \mu$ m blue-optical range. Five of these data sets are consistent with a transmission spectrum without any significant spectral features, while one shows a significant slope as a function of wavelength, which we interpret as arising from photospheric heterogeneities in the star. Coupled with HST /WFC3 infrared observations, our optical/near-infrared measurements point to the presence of high altitude clouds in WASP-19b's atmosphere in agreement with previous studies. Using a semi-analytical retrieval approach, considering both planetary and stellar spectral features, we find a water abundance consistent with solar for WASP-19b and strong evidence for sub-solar abundances for optical absorbers such as TiO and Na; no strong optical slope is detected, which suggests that if hazes are present, they are much weaker than previously suggested. In addition, two spot-crossing events are observed in our data sets and analysed, including one of the first unambiguously detected bright -spot-crossing events on an exoplanet host star.
- Is Part Of:
- Monthly notices of the Royal Astronomical Society. Volume 482:Issue 2(2019)
- Journal:
- Monthly notices of the Royal Astronomical Society
- Issue:
- Volume 482:Issue 2(2019)
- Issue Display:
- Volume 482, Issue 2 (2019)
- Year:
- 2019
- Volume:
- 482
- Issue:
- 2
- Issue Sort Value:
- 2019-0482-0002-0000
- Page Start:
- 2065
- Page End:
- 2087
- Publication Date:
- 2018-10-04
- Subjects:
- techniques: spectroscopic -- planets and satellites: atmospheres -- planets and satellites: individual: WASP-19b -- stars: activit -- stars: individual: WASP-19 -- starspots
Astronomy -- Periodicals
Periodicals
520.5 - Journal URLs:
- http://mnras.oxfordjournals.org/ ↗
http://onlinelibrary.wiley.com/journal/10.1111/(ISSN)1365-2966 ↗
http://www.blackwell-synergy.com/issuelist.asp?journal=mnr ↗
http://www.blackwell-synergy.com/loi/mnr ↗
http://ukcatalogue.oup.com/ ↗ - DOI:
- 10.1093/mnras/sty2691 ↗
- Languages:
- English
- ISSNs:
- 0035-8711
- Deposit Type:
- Legaldeposit
- View Content:
- Available online (eLD content is only available in our Reading Rooms) ↗
- Physical Locations:
- British Library DSC - 5943.000000
British Library DSC - BLDSS-3PM
British Library HMNTS - ELD Digital store - Ingest File:
- 11797.xml