Search Publications

The impact of a stealth CME on the Martian topside ionosphere
DOI: 10.1093/mnras/stab494 Bibcode: 2021MNRAS.503..625T

Nampoothiri, Govind G.; Thampi, Smitha V.; Pant, Tarun K. +1 more

Solar cycle 24 is one of the weakest solar cycles recorded, but surprisingly the declining phase of it had a slow coronal mass ejection (CME) that evolved without any low coronal signature and is classified as a stealth CME that was responsible for an intense geomagnetic storm at Earth (Dst = -176 nT). The impact of this space weather event on the…

2021 Monthly Notices of the Royal Astronomical Society
SOHO 15
Isotopes of chlorine from HCl in the Martian atmosphere
DOI: 10.1051/0004-6361/202140916 Bibcode: 2021A&A...651A..32T

Montmessin, F.; Korablev, O.; Fedorova, A. A. +7 more

Hydrogen chloride gas was recently discovered in the atmosphere of Mars during southern summer seasons. Its connection with potential chlorine reservoirs and the related atmospheric chemistry is now of particular interest and actively studied. Measurements by the Atmospheric Chemistry Suite mid-infrared channel (ACS MIR) on the ExoMars Trace Gas O…

2021 Astronomy and Astrophysics
ExoMars-16 15
Revealing the Vertical Cloud Structure of a Young Low-mass Brown Dwarf, an Analog to the β-Pictoris b Directly Imaged Exoplanet, through Keck I/MOSFIRE Spectrophotometric Variability
DOI: 10.3847/1538-3881/ac174c Bibcode: 2021AJ....162..179M

Lew, Ben W. P.; Karalidi, Theodora; Manjavacas, Elena +2 more

Young brown dwarfs are analogs to giant exoplanets, as they share effective temperatures, near-infrared colors, and surface gravities. Thus, the detailed characterization of young brown dwarfs might shed light on the study of giant exoplanets that we are currently unable to observe with a sufficient signal-to-noise to allow a precise characterizat…

2021 The Astronomical Journal
eHST 15
Evidence of the Gaia-VLBI position differences being related to radio source structure
DOI: 10.1051/0004-6361/202040168 Bibcode: 2021A&A...647A.189X

Xu, Ming H.; Savolainen, Tuomas; Anderson, James M. +3 more

Context. We report the relationship between the Gaia-VLBI position differences and the magnitudes of source structure effects in VLBI observations.
Aims: Because the Gaia-VLBI position differences are statistically significant for a considerable number of common sources, we discuss and attempt to explain these position differences based on VL…

2021 Astronomy and Astrophysics
Gaia 15
Completeness of the Gaia-verse III: using hidden states to infer gaps, detection efficiencies, and the scanning law from the DR2 light curves
DOI: 10.1093/mnras/staa3791 Bibcode: 2021MNRAS.501.2954B

Everall, Andrew; Boubert, Douglas; Fraser, Jack +2 more

The completeness of the Gaia catalogues heavily depends on the status of that space telescope through time. Stars are only published with each of the astrometric, photometric, and spectroscopic data products if they are detected a minimum number of times. If there is a gap in scientific operations, a drop in the detection efficiency or Gaia deviat…

2021 Monthly Notices of the Royal Astronomical Society
Gaia 15
The Gaia-ESO Survey: Oxygen Abundance in the Galactic Thin and Thick Disks
DOI: 10.3847/1538-3881/abc69b Bibcode: 2021AJ....161....9F

Kordopatis, Georges; Bragaglia, Angela; Adibekyan, Vardan +18 more

We analyze the oxygen abundances of a stellar sample representative of the two major Galactic populations: the thin and thick disks. The aim is to investigate the differences between members of the Galactic disks and contribute to the understanding of the origin of oxygen chemical enrichment in the Galaxy. The analysis is based on the [O I] = 6300…

2021 The Astronomical Journal
Gaia 15
A hot mini-Neptune in the radius valley orbiting solar analogue HD 110113
DOI: 10.1093/mnras/stab182 Bibcode: 2021MNRAS.502.4842O

Bouchy, F.; Deleuil, M.; Helled, R. +53 more

We report the discovery of HD 110113 b (TESS object of interest-755.01), a transiting mini-Neptune exoplanet on a 2.5-d orbit around the solar-analogue HD 110113 (Teff = 5730 K). Using TESS photometry and High Accuracy Radial velocity Planet Searcher (HARPS) radial velocities gathered by the NCORES program, we find that HD 110113 b has …

2021 Monthly Notices of the Royal Astronomical Society
Gaia 15
Investigation of Orbital Decay and Global Modeling of the Planet WASP-43 b
DOI: 10.3847/1538-3881/ac1baf Bibcode: 2021AJ....162..210D

Davoudi, Fatemeh; Safari, Hossein; Baştürk, Özgür +2 more

WASP-43 b is one of the most important candidates for detecting an orbital decay. We investigate pieces of evidence for this expectation as variations in its transit timings, based on the ground and space observations. The data set includes the transit observations at the TÜBİTAK National Observatory of Turkey and Transiting Exoplanet Survey Satel…

2021 The Astronomical Journal
Gaia eHST 15
Searching For Transiting Planets Around Halo Stars. II. Constraining the Occurrence Rate of Hot Jupiters
DOI: 10.3847/1538-3881/ac0e2d Bibcode: 2021AJ....162...85B

Li, Ting S.; Collins, Karen A.; Collins, Kevin I. +4 more

Jovian planet formation has been shown to be strongly correlated with host-star metallicity, which is thought to be a proxy for disk solids. Observationally, previous works have indicated that Jovian planets preferentially form around stars with solar and supersolar metallicities. Given these findings, it is challenging to form planets within meta…

2021 The Astronomical Journal
Gaia 15
OGLE-2018-BLG-1185b: A Low-mass Microlensing Planet Orbiting a Low-mass Dwarf
DOI: 10.3847/1538-3881/ac00ba Bibcode: 2021AJ....162...77K

Kim, S. -L.; Lee, C. -U.; Bryden, G. +96 more

We report an analysis of the planetary microlensing event OGLE-2018-BLG-1185, which was observed by a large number of ground-based telescopes and by the Spitzer Space Telescope. The ground-based light curve indicates a low planet-host star mass ratio of q = (6.9 ± 0.2) × 10-5, which is near the peak of the wide-orbit exoplanet mass-rati…

2021 The Astronomical Journal
Gaia eHST 15