Search Publications
The Young Massive Star Cluster Westerlund 2 Observed with MUSE. III. A Cluster in Motion—The Complex Internal Dynamics
Sabbi, Elena; Nota, Antonella; Zeidler, Peter +1 more
Analyzing the dynamical state of nearby young massive star clusters is essential for understanding star cluster formation and evolution during their earliest stages. In this work we analyze the stellar and gas kinematics of the young massive star cluster Westerlund 2 (Wd2) using data from the integral field unit Multi Unit Spectroscopic Explorer (…
Detection of Aerosols at Microbar Pressures in an Exoplanet Atmosphere
West, Robert; Swain, Mark R.; Estrela, Raissa +3 more
The formation of hazes at microbar pressures has been explored by theoretical models of exoplanet atmospheres to explain Rayleigh scattering and/or featureless transmission spectra; however observational evidence of aerosols in the low-pressure formation environments has proved elusive. Here, we show direct evidence of aerosols existing at ~1 micr…
Directly Determined Properties of HD 97658 from Interferometric Observations
Schaefer, Gail H.; Dragomir, Diana; von Braun, Kaspar +5 more
We conducted interferometric observations with the CHARA Array of transiting super-Earth host HD 97658 and measured its limb-darkened angular diameter to be θLD = 0.314 ± 0.004 mas. The combination of the angular diameter with the Gaia EDR3 parallax value with zero-point correction (π = 46.412 ± 0.022 mas, d =21.546 ± 0.011 pc) yields a…
TESS-Keck Survey. V. Twin Sub-Neptunes Transiting the Nearby G Star HD 63935
Batalha, Natalie M.; Latham, David W.; Mayo, Andrew W. +55 more
We present the discovery of two nearly identically sized sub-Neptune transiting planets orbiting HD 63935, a bright (V = 8.6 mag), Sun-like (Teff = 5560 K) star at 49 pc. TESS identified the first planet, HD 63935 b (TOI-509.01), in Sectors 7 and 34. We identified the second signal (HD 63935 c) in Keck High Resolution Echelle Spectromet…
An Intermediate-age Alpha-rich Galactic Population in K2
García, Rafael A.; Stello, Dennis; Beaton, Rachael L. +9 more
We explore the relationships between the chemistry, ages, and locations of stars in the Galaxy using asteroseismic data from the K2 mission and spectroscopic data from the Apache Point Galactic Evolution Experiment survey. Previous studies have used giant stars in the Kepler field to map the relationship between the chemical composition and the ag…
Keck/OSIRIS Paβ High-contrast Imaging and Updated Constraints on PDS 70b
Dong, Ruobing; Uyama, Taichi; Beichman, Charles A. +11 more
We present a high-contrast imaging search for Paβ line emission from protoplanets in the PDS 70 system with Keck/OSIRIS integral field spectroscopy. We applied the high-resolution spectral differential imaging technique to the OSIRIS J-band data but did not detect the Paβ line at the level predicted using the parameters of Hashimoto et al. (2020).…
Photometric and Spectroscopic Analysis of Four Contact Binaries
Joshi, Y. C.; Panchal, A.
We present the photometric and spectroscopic analysis of four W UMa binaries J015829.5+260333 (hereinafter as J0158), J030505.1+293443 (hereinafter as J0305), J102211.7+310022 (hereinafter as J1022), and KW Psc. The VRcIc band photometric observations are carried out with the 1.3 m Devasthal Fast Optical Telescope (DFOT). For…
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
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…
The Gaia-ESO Survey: Oxygen Abundance in the Galactic Thin and Thick Disks
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…
Investigation of Orbital Decay and Global Modeling of the Planet WASP-43 b
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…