相关论文: Relating Changes in Cometary Rotation to Activity:…
We present an extensive range of quantum calculations for the state-changing rotational dynamics involving two simple molecular anions which are expected to play some role in evolutionary analysis of chemical networks in the Interstellar…
There is an active debate about whether the properties of comets as observed today are primordial or, alternatively, if they are a result of collisional evolution or other processes. We investigate the effects of collisions on a comet with…
The Centaurs are recent escapees from the Kuiper belt that are destined either to meet fiery oblivion in the hot inner regions of the Solar system or to be ejected to the interstellar medium by gravitational scattering from the giant…
We present new lightcurve measurements of Comet 10P/Tempel 2 carried out with Lowell Observatory's Discovery Channel Telescope in early 2013 when the comet was at aphelion. These data represent some of the first science obtained with this…
Motivated by recent data on comets in the low corona, we discuss destruction of sun impacting comets in the dense lower solar atmosphere. Perihelion distances q less than the solar radius and incident masses Mo much greater than 1E12 g are…
We analyze a sample of 139 near-Earth asteroids (NEAs), defined as those that reach perihelion distances $q < 1.3$ au, and that also fulfill the conditions of approaching or crossing Jupiter's orbit (aphelion distances $Q > 4.8$ au), having…
We present CO(2-1), $^{13}$CO(2-1), CO(6-5), CO(7-6), and SO(6$_5-5_4$) line observations made with the {\it IRAM 30 m} and {\it APEX} radiotelescopes and the {\it Submillimeter Array} toward the highly collimated and extended southwest…
The compositional and morphological evolution of minor bodies in the Solar System is primarily driven by the evolution of their heliocentric distances, as the level of incident solar radiation regulates cometary activity. We investigate the…
The line emission in the coma was measured in the comets C/2001 Q4 (NEAT) and C/2002 T7 (LINEAR), that were observed on five consecutive nights, 7-11 May 2004, at heliocentric distances of 1.0 and 0.7 AU, respectively, by means of…
We use X-ray observations of the nearby binaries 61 Cyg A/B (K5V and K7V) and Alpha Cen A/B (G2V and K1V) to study the long-term evolution of magnetic activity in weakly to moderately active G + K dwarfs over nearly a decade. Specifically…
Strongly magnetized, accreting neutron stars show periodic and aperiodic variability over a wide range of time scales. By obtaining spectral and timing information on these different time scales, we can have a closer look into the physics…
We examine the dynamics of small bodies in orbits similar to that of comet 29P/Schwassmann-Wachmann 1, i.e. near-circular orbits between Jupiter and Saturn. As of late 2019, there are 14 other known bodies in this region that lie in similar…
A neutron star in binary orbit with a low-mass non-degenerate companion becomes a source of x-rays with millisecond variability when mass accretion spins it up. Centrifugally driven changes in density profile may initiate a phase transition…
Observing [O I] emission to calculate an "oxygen line ratio" has been proposed as a potential proxy for direct CO$_2$ measurement in comets. However, the photochemistry governing [O I] release into the coma is not well understood, and using…
Comets are a rich reservoir of complex organic molecules. Ground and space-based observatories have recently greatly enhanced the cometary molecular inventory. Although these molecules' origin is believed to be the cometary nucleus, they…
The X-ray pulsar SMC X-1 shows a superorbital modulation with an unstable cycle length in the X-ray band. We present its timing behaviors, including the spin, orbital, and superorbital modulations, beyond the end of the Rossi X-ray Timing…
One monolayer of C60 on one monolayer of hexagonal boron nitride on nickel is investigated by photoemission. Between 150 and 250 K the work function decreases and the binding energy of the highest occupied molecular orbital (HOMO) increases…
A density disturbance in a system of gravitating mass, induced by a moving selected body gives rise to a dynamical screening of Newtonian potential of this body. When applied to the solar planetary system it means that as a result of the…
It is noted that effective very recently, the orbital motion of Encke's comet has become affected by a very slight nongravitational deceleration. Soon after J. F. Encke established in the early 19th century that the comet was returning to…
We observed the interstellar comet 2I/Borisov using the Neil Gehrels-Swift Observatory's Ultraviolet/Optical Telescope. We obtained images of the OH gas and dust surrounding the nucleus at six epochs spaced before and after perihelion…