Search Publications
Titan's haze at opposite seasons from HST-STIS spectroscopy
Karkoschka, Erich
We present an analysis of three new image cubes of Titan by the Space Telescope Imaging Spectrograph taken in 2017, 2018, and 2019, half a Titan year after previously analyzed image cubes. Both data sets probe periods when Titan's seasonal north-south-asymmetry switched. The new observations show that the new reversal came exactly half a Titan yea…
Adsorption-driven Gas Trapping in Cometary Ice Analogs
Yokochi, Reika
Icy planetary bodies carry volatiles in abundances that should reflect the conditions of their formation. However, the interpretation of volatile abundance data from comets is complicated by the fact that the governing parameters and underlying mechanism of volatile trapping are poorly constrained. To unravel the mechanism of gas trapping in water…
Ma'adim Vallis, Mars: Insights into episodic and late-stage water activity from an impact crater
Harish; Vijayan, S.; Tuhi, S. +4 more
Alluvial fans, a form of sedimentary deposit reported on Mars, offer insight into the evolution and nature of fluvial activity on the planet. Additionally, the region's preserved mineralogy can also be used to study its hydrological history. In this context, we discuss the diverse geomorphology and mineralogy of an unnamed crater that formed on th…
Activity of the Young Star TOI 837 with an Exoplanet
Savanov, I. S.
—Based on high-precision data from the archive of the TESS space mission, a study was made of the photometric brightness variability of TOI 837—a young star with an exoplanet, a member of the southern sky cluster IC 2602. Based on all available observational results, we have estimated the star's rotation period and brightness variability amplitude…
Testing Model-determined Temperatures in the Hyades: A Bayesian Approach
Joner, Michael D.; Jeffery, Elizabeth J.; Taylor, Benjamin J.
Gains in our understanding of stellar evolution over the last century are largely due to improvements in stellar models. One key aspect in the use of these models is a reliable transformation between theoretical values (such as luminosity and temperature) to observable quantities (such as magnitude and color). To assess the current state of this t…
Sub-field of view surface thermal modeling of Cassini CIRS observations of Rhea during south polar winter
Howett, Carly J. A.; Miles, Georgina; Spencer, John +1 more
Rhea's exosphere is thought to originate from sources of carbon, water ice and other volatiles that arrived at Rhea by bombardment. Its seasonal variability is directly driven by polar surface temperatures allowing surface adsorption, and the persistence of source volatiles require that seasonal temperatures remain sufficiently cold to retain them…
Quaternionic Transform: A new Light on the Solar Power Spectrum
Garrido, Rafael; Ayala, Adrián; Pascual-Granado, Javier +2 more
Asteroseismology, that is, the use of the frequency content of a time series caused by variations in brightness or radial velocity of a stellar object, is based on the hypothesis that such a series is harmonic and therefore can be described by a sum of sines and cosines. If this were not the case (e.g., the oscillations of an ellipsoid of revoluti…
Fundamental parameters of barium and CH stars from asteroseismic analysis: HD 33409, HD 20084 and HD 66812
Goswami, Aruna; Sonamben, Mayani
Asteroseismic analysis of stars using space mission data, such as the transiting exoplanet survey satellite (TESS) allows us to derive accurate fundamental parameters of stars. Barium and CH stars are believed to be in binary systems with a now invisible white dwarf companion. Knowledge of accurate fundamental parameters of these stars is essentia…
Investigating star-formation activity towards the southern H II region RCW 42
Ojha, D. K.; Vig, S.; Ghosh, S. K. +4 more
The star-forming activity in the H II region RCW 42 is investigated using multiple wavebands, from near-infrared to radio wavelengths. Located at a distance of 5.8 kpc, this southern region has a bolometric luminosity of 1.8 × 106 L⊙. The ionized gas emission has been imaged at low radio frequencies of 610 and 1280 MHz using …
From hot to cold? - Hydrothermal activities as a source for icy-debris flows on Dryas Mons, Terra Sirenum, Mars
Hauber, E.; Martin, P.; Cardesín-Moinelo, A. +3 more
During an extensive grid-mapping campaign on Mars' southern hemisphere, we have detected so-called sheet flow deposits, which are defined by distinctive lobate fronts, thin and mostly planar layers, and faint sub-parallel surface lineations. They originate from the high plains of Dryas Mons, a large massif of impact and tectonic origin, and follow…