ExoAtmospheres
IAC community database for exoplanet atmospheric observations
MASCARA-2 b/KELT-20 b
| Planet status | Confirmed |
|---|---|
| Planet type | UltraHot Jupiter |
| Period | 3.4741085 d |
| Mass | 3.518 MJ 1118.0204 M⊕ |
| Radius | 1.83 RJ 20.496 R⊕ |
| Semi major axis | 0.0542 AU |
| Star name | MASCARA-2 |
| Star distance | N/A |
| Star teff | 8980 K |
| Star radius | 1.6 R☉ |
| Temperature (calculated) | 2230 K |
| V | 3 mag |
| J | N/A |
| K | N/A |
| Alternate names | HD 185603 b, MASCARA-2 b |
| Exoplanet Encyclopaedia |  |
Molecules
Ca: Detection Fe: Detection Ni: Detection
|
G-B: High resolution visible | PEPSI Investigation, Retrieval, and Atlas of Numerous Giant Atmospheres (PIRANGA). IV. High-resolution Phased-resolved Spectroscopy of the Ultra-hot-Jupiter KELT-20 b2026, Bonidie, Victoria, Johnson, Marshall C. et al. |
|
Fe: Detection Fe+: Detection
|
G-B: High resolution visible | PEPSI Investigation, Retrieval, and Atlas of Numerous Giant Atmospheres (PIRANGA). II. Phase-Resolved Cross-Correlation Transmission Spectroscopy of KELT-20b2025, Calder Lenhart, Marshall C. Johnson et al. |
|
CO: Detection H2O: Detection Molecular ratios: C/O, etc...: Detection
|
G-B: High resolution IR | Water dissociation and rotational broadening in the atmosphere of KELT-20 b from high-resolution spectroscopy2025, Luke Finnerty, Yinzi Xin et al. |
Lower limit on water abundance |
Na: Detection
|
G-B: High resolution visible | The GAPS programme at TNG LXVI. A homogeneous search for Na i and its possible variability in ten gas giant exoplanets2024, D. Sicilia, L. Malavolta et al. |
Study of the strenght of the Na doublet lines from several transits |
Fe+: Detection
|
G-B: High resolution visible | The GAPS programme at TNG: TBD. Studies of atmospheric FeII winds in ultra-hot Jupiters KELT-9b and KELT-20b using HARPS-N spectrograph2024, M. Stangret, L. Fossati et al. |
|
Albedo: 0.1 Phase curve: Yes Dayside Temperature (occultation): 2820 K |
Spitzer | A Comprehensive Analysis Spitzer 4.5 $μ$m Phase Curve of Hot Jupiters2024, Lisa Dang, Taylor J. Bell et al. |
Dayside and nightside temperatures from phase curve at 4.5 um. |
He: Upper limit
|
G-B: High resolution IR | The MOPYS project: A survey of 70 planets in search of extended He I and H atmospheres. No evidence of enhanced evaporation in young planets2024, J. Orell-Miquel, F. Murgas et al. |
|
Albedo: 0.36 |
CHEOPS | CHEOPS observations of KELT-20 b/MASCARA-2 b: an aligned orbit and signs of variability from a reflective dayside2023, V. Singh, G. Scandariato et al. |
indications of variable cloud cover advecting onto the planetary dayside |
Fe: Detection Ni: Detection Cr: No detection
|
G-B: High resolution visible | The PEPSI Exoplanet Transit Survey (PETS) IV: Assessing the atmospheric chemistry of KELT-20b2023, Sydney Petz, Marshall C. Johnson et al. |
|
H: Detection
|
G-B: High resolution visible | The GAPS programme at TNG. XLV. HI Balmer lines transmission spectroscopy and NLTE atmospheric modelling of the ultra-hot Jupiter KELT-20b/MASCARA-2b2023, Fossati, L., Biassoni, F. et al. |
Hα, Hβ, Hγ (detection) and Hδ (almost 4sigma) with HARPS-N + comparison with the theoretical LTE/non-LTE models |
Fe: Detection Mg: Detection Ni: Upper limit Cr: Detection Mn: Detection V: Upper limit Ca: Detection Ti: Upper limit Na: Upper limit
|
G-B: High resolution visible | Retrieval Survey of Metals in Six Ultrahot Jupiters: Trends in Chemistry, Rain-out, Ionization, and Atmospheric Dynamics2023, Gandhi, Siddharth, Kesseli, Aurora et al. |
|
Fe+: Detection Ni+: Detection
|
G-B: High resolution visible | Unifying High- and Low-resolution Observations to Constrain the Dayside Atmosphere of KELT-20b/MASCARA-2b2022, David Kasper, Jacob L. Bean et al. |
Constraints on the abundances of Fe i, H2O, and CO, and a stringent upper limit on the TiO abundance. |
Fe+: No detection Cr: No detection Fe: Detection
|
G-B: High resolution visible | The PEPSI-LBT Exoplanet Transit Survey (PETS). II. A Deep Search for Thermal Inversion Agents in KELT-20 b/MASCARA-2 b with Emission and Transmission Spectroscopy2022, Marshall C. Johnson, Ji Wang et al. |
|
Na: Detection
|
G-B: High resolution visible | A survey of sodium absorption in ten giant exoplanets with high-resolution transmission spectroscopy2022, Adam B. Langeveld, Nikku Madhusudhan et al. |
Confirmed the previously reported detections of Na using HARPS-N. |
Fe: Detection Fe+: Detection Cr: Detection
|
G-B: High resolution visible | The GAPS Programme at TNG XXXIII. HARPS-N detects multiple atomic species in emission from the dayside of KELT-20b2022, F. Borsa, P. Giacobbe et al. |
Species detected in emission |
Fe+: Detection
|
G-B: High resolution visible | Exoplanet atmospheres at high resolution through a modest-size telescope. Fe II in MASCARA-2b and KELT-9b with FIES on the Nordic Optical Telescope2022, Aaron Bello-Arufe, Lars A. Buchhave et al. |
|
Fe: Detection
|
G-B: High resolution visible | Detection of iron emission lines and a temperature inversion on the dayside of the ultra-hot Jupiter KELT-20b2022, Yan, F., Reiners, A. et al. |
Detection of FeI in emission using CARMENES observations |
H2O: Detection CO: Detection
|
HST WFC3 | Strong H$_2$O and CO emission features in the spectrum of KELT-20b driven by stellar UV irradiation2022, Guangwei Fu, David K. Sing et al. |
Detected in emission. Also use TESS and Spitzer data |
CO: Detection H2O: Detection
|
TESS | Strong H<SUB>2</SUB>O and CO Emission Features in the Spectrum of KELT-20b Driven by Stellar UV Irradiation2022, Fu, Guangwei, Sing, David K. et al. |
'The emission spectrum covers 0.6-4.5 μm with data from TESS, HST WFC3/G141, and Spitzer 4.5 μm channel' |
Si: Detection
|
G-B: High resolution IR | Silicon in the dayside atmospheres of two ultra-hot Jupiters2021, D. Cont, F. Yan et al. |
High-resolution emission spectroscopy in the near-infrared with CARMENES. |
Phase curve: Yes |
TESS | Visible-light Phase Curves from the Second Year of the TESS Primary Mission2021, Ian Wong, Daniel Kitzmann et al. |
Secondary eclipse (D=111+/-36 ppm) and planetary phase curve measured. |
FeH: Upper limit
|
G-B: High resolution IR | A Search for FeH in Hot-Jupiter Atmospheres with High-dispersion Spectroscopy2020, Kesseli, Aurora Y., Snellen, I. A. G. et al. |
|
Fe: Detection Fe+: Detection Na: Detection Mg: Detection Cr+: Detection
|
G-B: High resolution visible | High-resolution transmission spectroscopy of MASCARA-2 b with EXPRES2020, Hoeijmakers, H. Jens, Cabot, Samuel H. C. et al. |
Confirmations of Fe, Fe+ and Na and new detections of Mg and Cr+ using transit observations with EXPRES |
Fe: Detection Fe+: Detection Ca+: Detection Na: Detection
|
G-B: High resolution visible | Searching for thermal inversion agents in the transmission spectrum of KELT-20b/MASCARA-2b: detection of neutral iron and ionised calcium H&K lines2020, Nugroho, Stevanus K., Gibson, Neale P. et al. |
HARPS-N and CARMENES observations |
Fe: Detection Fe+: Detection
|
G-B: High resolution visible | Detection of Fe I and Fe II in the atmosphere of MASCARA-2b using a cross-correlation method2020, Stangret, M., Casasayas-Barris, N. et al. |
Detection of Fe I and Fe II using HARPS-N observations, using a cross-correlation method |
H: Detection Na: Detection Ca+: Detection Fe+: Detection
|
G-B: High resolution visible | Atmospheric characterization of the ultra-hot Jupiter MASCARA-2b/KELT-20b. Detection of CaII, FeII, NaI, and the Balmer series of H (Hα, Hβ, and Hγ) with high-dispersion transit spectroscopy2019, Casasayas-Barris, N., Pallé, E. et al. |
HARPS-N and CARMENES observations |
H: Detection Na: Detection
|
G-B: High resolution visible | Na I and Hα absorption features in the atmosphere of MASCARA-2b/KELT-20b2018, Casasayas-Barris, N., Pallé, E. et al. |
Detection of sodium (Na I) doublet and the Halpha using HARPS-N observation |