Search Publications
Complex organosulfur molecules on comet 67P: Evidence from the ROSINA measurements and insights from laboratory simulations
Ehlmann, Bethany L.; Brown, Michael E.; Choukroun, Mathieu +9 more
The ROSINA (Rosetta Orbiter Spectrometer for Ion and Neutral Analysis) instrument aboard the Rosetta mission revolutionized our understanding of cometary material composition. One of Rosetta's key findings is the complexity of the composition of comet 67P/Churyumov-Gerasimenko. Here, we used ROSINA data to analyze dust particles that were volatili…
ALMA High-frequency Long Baseline Campaign in 2021: Highest Angular Resolution Submillimeter Wave Images for the Carbon-rich Star R Lep
Hirota, Akihiko; Hales, Antonio S.; Takahashi, Satoko +11 more
The Atacama Large Millimeter/submillimeter Array (ALMA) was used in 2021 to image the carbon-rich evolved star R Lep in Bands 8-10 (397-908 GHz) with baselines up to 16 km. The goal was to validate the calibration, using band-to-band (B2B) phase referencing with a close phase calibrator J0504-1512, 1.°2 from R Lep in this case, and the imaging pro…
δ Scuti pulsations in the bright Pleiades eclipsing binary HD 23642
Southworth, John; Murphy, S. J.; Pavlovski, K.
We announce the discovery of pulsations in HD 23642, the only bright eclipsing system in the Pleiades, based on light curves from the Transiting Exoplanet Survey Satellite (TESS). We measure 46 pulsation frequencies and attribute them to δ Scuti pulsations in the secondary component. We find four ℓ = 1 doublets, three of which have frequency split…
An eclipsing 47 min double white dwarf binary at 400 pc
Kepler, S. O.; Hermes, J. J.; Dhillon, V. S. +20 more
We present the discovery of the eclipsing double white dwarf (WD) binary WDJ 022558.21-692025.38 that has an orbital period of 47.19 min. Following identification with the Transiting Exoplanet Survey Satellite, we obtained time series ground based spectroscopy and high-speed multiband ULTRACAM photometry which indicate a primary DA WD of mass $0.4…
ALMA 1.1 mm Observations of a Conservative Sample of High-redshift Massive Quiescent Galaxies in SHELA
Papovich, Casey; Finkelstein, Steven L.; Bagley, Micaela B. +11 more
We present a sample of 30 massive (log(M */M ⊙) > 11) z = 3-5 quiescent galaxies selected from the Spitzer-HETDEX Exploratory Large Area (SHELA) Survey and observed at 1.1 mm with Atacama Large Millimeter/submillimeter Array (ALMA) Band 6 observations. These ALMA observations would detect even modest levels of dust-obscure…
Astro-COLIBRI 2—An Advanced Platform for Real-Time Multi-Messenger Discoveries
Reichherzer, Patrick; Schüssler, Fabian; Lefranc, Valentin +3 more
The study of flaring astrophysical events in the multi-messenger approach requires instantaneous follow-up observations to better understand the nature of these events through complementary observational data. We present Astro-COLIBRI as a platform that integrates specific tools in the real-time multi-messenger ecosystem. The Astro-COLIBRI platfor…
Discovery of the Exceptionally Short Period Ultracool Dwarf Binary LP 413-53AB
Burgasser, Adam J.; Hsu, Chih-Chun; Theissen, Christopher A.
We report the detection of large-amplitude, rapid radial velocity (RV) variations and line-splitting in high-resolution Keck/NIRSPEC spectra of the M9 dwarf LP 413-53. We attribute these features to binary motion. Analyzing data spanning 15 yr, we infer a preliminary orbital period of 0.7106156 ± 0.0000002 days, an eccentricity of 0.0088 ± 0.0017,…
Hot white dwarfs and pre-white dwarfs discovered with SALT
Werner, K.; Jeffery, C. S.; Miszalski, B. +3 more
The Southern African Large Telescope survey of helium-rich hot subdwarfs aims to explore evolutionary pathways among groups of highly evolved stars. The selection criteria mean that several hot white dwarfs and related objects have also been included. This paper reports the discovery and analysis of eight new very hot white dwarf and pre-white dwa…
A systematic validation of hot Neptunes in TESS data
Bieryla, Allyson; Howell, Steve B.; Ziegler, Carl +26 more
We statistically validated a sample of hot Neptune candidates applying a two-step vetting technique using DAVE and TRICERATOPS. We performed a systematic validation of 250 transit-like events in the Transiting Exoplanet Survey Satellite archive in the parameter region defined by $P\le 4\, \text{d}$ and $3\, {\rm R}_{\oplus }\le R \le 5\, {\rm R}_{…
The Metallicity and Distance of Leo A from Blue Supergiants
Bresolin, Fabio; Kudritzki, Rolf-Peter; Urbaneja, Miguel A.
We have obtained high-quality spectra of blue supergiant candidates in the dwarf irregular galaxy Leo A with the Low Resolution Imaging Spectrometer at the Keck I telescope. From the quantitative analysis of seven B8-A0 stars, we derive a mean metallicity [Z] = -1.35 ± 0.08, in excellent agreement with the gas-phase chemical abundance. From the st…