Search Publications
Character and Spatial Distribution of OH/H2O on the Surface of the Moon Seen by M3 on Chandrayaan-1
Clark, R. N.; Head, J. W.; Kumar, S. +26 more
The search for water on the surface of the anhydrous Moon had remained an unfulfilled quest for 40 years. However, the Moon Mineralogy Mapper (M3) on Chandrayaan-1 has recently detected absorption features near 2.8 to 3.0 micrometers on the surface of the Moon. For silicate bodies, such features are typically attributed to hydroxyl- and…
Imaging the Interaction of the Heliosphere with the Interstellar Medium from Saturn with Cassini
Hsieh, K. C.; Krimigis, S. M.; Mitchell, D. G. +2 more
We report an all-sky image of energetic neutral atoms (ENAs) >6 kilo-electron volts produced by energetic protons occupying the region (heliosheath) between the boundary of the extended solar atmosphere and the local interstellar medium (LISM). The map obtained by the Ion and Neutral Camera (INCA) onboard Cassini reveals a broad belt of energet…
The Disappearance of the Progenitors of Supernovae 1993J and 2003gd
Smartt, Stephen J.; Maund, Justyn R.
Using images from the Hubble Space Telescope and the Gemini Telescope, we confirmed the disappearance of the progenitors of two type II supernovae (SNe) and evaluated the presence of other stars associated with them. We found that the progenitor of SN 2003gd, an M-supergiant star, is no longer observed at the SN location and determined its intrins…
An Ultramassive, Fast-Spinning White Dwarf in a Peculiar Binary System
Tiengo, A.; Mereghetti, S.; Stella, L. +3 more
White dwarfs typically have masses in a narrow range centered at about 0.6 solar mass (M⊙). Only a few ultramassive white dwarfs (mass > 1.2 M⊙) are known. Those in binary systems are of particular interest, because a small amount of accreted mass could drive them above the Chandrasekhar limit, beyond which they become gra…
A Population of Compact Elliptical Galaxies Detected with the Virtual Observatory
Revaz, Yves; Micol, Alberto; Chilingarian, Igor +5 more
Compact elliptical galaxies are characterized by small sizes and high stellar densities. They are thought to form through tidal stripping of massive progenitors. However, only a handful of them were known, preventing us from understanding the role played by this mechanism in galaxy evolution. We present a population of 21 compact elliptical galaxi…
Size and Shape of Saturn's Moon Titan
Kirk, Randolph L.; Hensley, Scott; Zebker, Howard A. +3 more
Cassini observations show that Saturn’s moon Titan is slightly oblate. A fourth-order spherical harmonic expansion yields north polar, south polar, and mean equatorial radii of 2574.32 ± 0.05 kilometers (km), 2574.36 ± 0.03 km, and 2574.91 ± 0.11 km, respectively; its mean radius is 2574.73 ± 0.09 km. Titan’s shape approximates a hydrostatic, sync…
The Shape and Surface Variation of 2 Pallas from the Hubble Space Telescope
Russell, C. T.; Stern, S. A.; Mutchler, M. J. +8 more
We obtained Hubble Space Telescope images of 2 Pallas in September 2007 that reveal distinct color and albedo variations across the surface of this large asteroid. Pallas’s shape is an ellipsoid with radii of 291 (±9), 278 (±9), and 250 (±9) kilometers, implying a density of 2400 (±250) kilograms per cubic meter—a value consistent with a body that…