Search Publications
Ultraviolet observation of Enceladus' plume in transit across Saturn, compared to Europa
Hansen, C. J.; Hendrix, A. R.; Esposito, L. W.
Saturn's moon Enceladus is known to have a water vapor plume erupting from fissures across its south polar region. The plume was detectable in an observation of Enceladus transiting Saturn by Cassini's Ultraviolet Imaging Spectrograph (UVIS), but only at 1216 Å (Lyman alpha). Jupiter's moon Europa also may have multiple water vapor plumes, detecte…
Magnetic activity of the young solar analog V1358 Orinis
Granzer, T.; Carroll, T. A.; Kriskovics, L. +3 more
Context. Young, fast-rotating single stars can show dramatically different magnetic signatures and levels of magnetic activity as compared with the Sun. While losing angular momentum due to magnetic breaking and mass loss through stellar winds, the stars gradually spin down resulting in decreasing levels of activity. Studying magnetic activity on …
A Thermal Inertia Map of Titan
MacKenzie, Shannon M.; Lorenz, Ralph D.; Lora, Juan M.
Like Earth, the atmosphere of Titan, Saturn's largest moon, is affected by the ability of the surface to store and release heat. Modeling efforts have shown that global temperature distributions and wind profiles differ between simulations describing Titan's surface with a uniform thermal inertia. Cassini-Huygens demonstrated, however, that a vari…
Stellar masses from granulation and oscillations of 23 bright red giants observed by BRITE-Constellation
Handler, G.; Wade, G. A.; Hekker, S. +11 more
Context. The study of stellar structure and evolution depends crucially on accurate stellar parameters. The photometry from space telescopes has provided superb data that enabled the asteroseismic characterisation of thousands of stars. However, typical targets of space telescopes are rather faint and complementary measurements are difficult to ob…
APOGEE/Kepler Overlap Yields Orbital Solutions for a Variety of Eclipsing Binaries
Stassun, Keivan G.; Agol, Eric; Rawls, Meredith L. +4 more
Spectroscopic eclipsing binaries (SEBs) are fundamental benchmarks in stellar astrophysics and today are observed in breathtaking detail by missions like the Transiting Exoplanet Survey Satellite (TESS), Kepler, and Apache Point Observatory Galactic Evolution Experiment (APOGEE). We develop a methodology for simultaneous analysis of high-precision…
The Variability of Solar Coronal Abundances in Active Regions and the Quiet Sun
Doschek, G. A.; Warren, H. P.
Measurements of elemental abundances hold important clues to how mass and energy flow through the solar atmosphere. Variations in abundances are organized by an element’s first ionization potential (FIP), and many previous studies have assumed that low FIP (less than 10 eV) elements are enriched by a factor of 3-4 in the corona. In this paper, we …
The Ultraviolet Detection of Diffuse Gas in Galaxy Groups
Danforth, Charles W.; Stocke, John T.; Jannuzi, Buell +5 more
A small survey of the UV-absorbing gas in 12 low-z galaxy groups has been conducted using the Cosmic Origins Spectrograph on board the Hubble Space Telescope. Targets were selected from a large, homogeneously selected sample of groups found in the Sloan Digital Sky Survey. A critical selection criterion excluded sight lines that pass close (<1.…
Optical Counterparts of ULXs and Their Host Environments in NGC 4490/4485
Balman, Şölen; Fabrika, Sergei; Akyuz, Aysun +6 more
We report the identification of the possible optical counterparts of five out of seven ultraluminous X-ray sources (ULXs) in the galaxy pair NGC 4490/4485. Using archival Hubble Space Telescope (HST) imaging data, we identified a single optical candidate for two ULXs (X-4 and X-7) and multiple optical candidates for the other three (X-2, X-3, and …
First measurements of Jupiter's zonal winds with visible imaging spectroscopy
Sato, Bun'ei; Rivet, Jean-Pierre; Guillot, Tristan +12 more
We present the first measurements of Jupiter's wind profile ever obtained with Doppler velocity measurements in the visible. Hitherto, knowledge about atmospheric dynamics has been obtained with cloud-tracking techniques, which consist of tracking visible features from images taken at different dates. However, cloud tracking indicates the motion o…
Mapping of shadows cast on a protoplanetary disk by a close binary system
van der Plas, G.; Avenhaus, H.; Girard, J. +47 more
For a comprehensive understanding of planetary formation and evolution, we need to investigate the environment in which planets form: circumstellar disks. Here we present high-contrast imaging observations of V4046 Sagittarii, a 20-Myr-old close binary known to host a circumbinary disk. We have discovered the presence of rotating shadows in the di…