相关论文: Hubble Space Telescope Search for Activity in High…

The accumulation of mass from the interaction process that forms the polar ring galaxies is a factor that favors the conditions necessary to trigger nonthermal nuclear activities.. This fact encouraged the chemical analysis of ten polar…

In the absence of H_2 molecules, the primordial gas in early dark matter halos with virial temperatures just above T_vir >~ 10^4 K cools by collisional excitation of atomic H. Although it cools efficiently, this gas remains relatively hot,…

This work aims to study the unexplained sulfur depletion observed toward dense clouds and protostars. We made simulation experiments of the UV-photoprocessing and sublimation of H2S and H2S:H2O ice in dense clouds and circumstellar regions,…

Context: Increasingly, Oort Cloud comets are being discovered at great distances from the Sun and tracked over ever wider ranges of heliocentric distances as observational equipment improves. Aims: To investigate in detail how the original…

Magnetic activity on stars manifests itself in the form of dark spots on the stellar surface, that cause modulation of a few percent in the light curve of the star as it rotates. When a planet eclipses its host star, it might cross in front…

Many planets orbit within an AU of their stars, raising questions about their origins. Particularly puzzling are the planets found near the silicate sublimation front. We investigate conditions near the front in the protostellar disk around…

Bayesian atmospheric retrieval tools can place constraints on the properties of brown dwarfs and hot Jupiters atmospheres. To fully exploit these methods, high signal-to-noise spectral libraries with well-understood uncertainties are…

Comet Hale--Bopp (C/1995 O1) has been the single most significant comet encountered by modern astronomy, still having displayed significant activity at 25.7 AU solar distance in late 2007. It is a puzzling question when and where this…

Among the outer solar system minor planet orbits there is an observed gap in perihelion between roughly 50 and 65 au at eccentricities $e\gtrsim0.65$. Through a suite of observational simulations, we show that the gap arises from two…

W5-E has been observed with the Herschel-PACS and -SPIRE photometers, at 100, 160, 250, 350, and 500 microns. The dust temperature map shows a rather uniform temperature, in the range 17.5-20 K in the dense condensations or filaments, 21-22…

A review of the Hubble Space Telescope H0 Key Project is given, as presented at the IAU Symposium 183 on "Cosmological Parameters" held in Kyoto, Japan in August, 1997. An outline of the goals and progress toward this effort is given.…

We utilize Kepler data to study the precision differential photometric variability of solar-type and cooler stars at different timescales, ranging from half an hour to 3 months. We define a diagnostic that characterizes the median…

We study the activity evolution of the main-belt comet 324P/La Sagra over time and the properties of its emitted dust. We performed aperture photometry on images taken by a wide range of telescopes at optical and thermal infrared…

Hot temperature minerals have been detected in a large number of comets and were also identified in the samples of Comet Wild 2 that were returned by the Stardust mission. Meanwhile, observations of the distribution of hot minerals in young…

Centaurs are inward-scattered Kuiper belt objects, with some exhibiting comet-like activity. The physical mechanisms powering this activity remain poorly understood, with carbon monoxide (CO) sublimation or the crystallization of amorphous…

Hydrogen recombination lines (HRLs) are valuable diagnostics of the physical conditions in ionized regions around high-mass stars. Understanding their broadening mechanisms and intensity trends can provide insights into the densities,…

The Debye-H\"uckel theory describes rigorously the thermal equilibrium of classical Coulomb fluids in the high-temperature $\beta\to 0$ regime ($\beta$ denotes the inverse temperature). It is generally believed that the Debye-H\"uckel…

We present a series of observations of the return of activity in main-belt comet 238P/Read. Using data obtained in July and August 2010 when 238P appeared to be largely inactive, we find best-fit IAU phase function parameters of…

High contrast imaging searches for exoplanets have been conducted on 2.4-10 m telescopes, typically at H band (1.6 microns) and used exposure times of ~1 hr to search for planets with semi-major axes of > ~10 AU. We are beginning to plan…

We present Hubble Space Telescope optical and near-ultraviolet transmission spectra of the transiting hot-Jupiter HD189733b, taken with the repaired Space Telescope Imaging Spectrograph (STIS) instrument. The resulting spectra cover the…