TY - JOUR
T1 - High-resolution transmission spectroscopy of MASCARA-2 b with EXPRES
AU - Jens Hoeijmakers, H.
AU - Cabot, Samuel H.C.
AU - Zhao, Lily
AU - Buchhave, Lars A.
AU - Tronsgaard, Rene
AU - Davis, Allen B.
AU - Kitzmann, Daniel
AU - Grimm, Simon L.
AU - Cegla, Heather M.
AU - Bourrier, Vincent
AU - Ehrenreich, David
AU - Heng, Kevin
AU - Lovis, Christophe
AU - Fischer, Debra A.
PY - 2020
Y1 - 2020
N2 - We report detections of atomic species in the atmosphere of MASCARA-2 b, using the first transit observations obtained with the newly commissioned EXPRES spectrograph. EXPRES is a highly stabilized optical echelle spectrograph, designed to detect stellar reflex motions with amplitudes down to 30 cm s-1, and has recently been deployed at the Lowell Discovery Telescope. By analyzing the transmission spectrum of the ultra-hot Jupiter MASCARA-2 b using the cross-correlation method, we confirm previous detections of Fe※ I, Fe※ II, and Na※ I, which likely originate in the upper regions of the inflated atmosphere. In addition, we report significant detections of Mg※ I and Cr※ II. The absorption strengths change slightly with time, possibly indicating different temperatures and chemistry in the day- and nightside terminators. Using the effective stellar line-shape variation induced by the transiting planet, we constrain the projected spin-orbit misalignment of the system to 1.6 ± 3.1 degrees, consistent with an aligned orbit. We demonstrate that EXPRES joins a suite of instruments capable of phase-resolved spectroscopy of exoplanet atmospheres.
AB - We report detections of atomic species in the atmosphere of MASCARA-2 b, using the first transit observations obtained with the newly commissioned EXPRES spectrograph. EXPRES is a highly stabilized optical echelle spectrograph, designed to detect stellar reflex motions with amplitudes down to 30 cm s-1, and has recently been deployed at the Lowell Discovery Telescope. By analyzing the transmission spectrum of the ultra-hot Jupiter MASCARA-2 b using the cross-correlation method, we confirm previous detections of Fe※ I, Fe※ II, and Na※ I, which likely originate in the upper regions of the inflated atmosphere. In addition, we report significant detections of Mg※ I and Cr※ II. The absorption strengths change slightly with time, possibly indicating different temperatures and chemistry in the day- and nightside terminators. Using the effective stellar line-shape variation induced by the transiting planet, we constrain the projected spin-orbit misalignment of the system to 1.6 ± 3.1 degrees, consistent with an aligned orbit. We demonstrate that EXPRES joins a suite of instruments capable of phase-resolved spectroscopy of exoplanet atmospheres.
KW - Instrumentation: spectrographs
KW - Planets and satellites: atmospheres
KW - Techniques: spectroscopic
KW - Planets and satellites: gaseous planets
U2 - 10.1051/0004-6361/202037437
DO - 10.1051/0004-6361/202037437
M3 - Journal article
SN - 0004-6361
VL - 641
JO - Astronomy and Astrophysics
JF - Astronomy and Astrophysics
M1 - A120
ER -