scholarly journals The effect of the rotation of a planetary atmosphere upon the orbit of a close satellite.

1959 ◽  
Vol 64 ◽  
pp. 54
Author(s):  
Theodore E. Sterne
Keyword(s):  
Planetary Atmosphere ◽  
Close Satellite

Effect of the Rotation of a Planetary Atmosphere Upon the Orbit of a Close Satellite

ARS Journal ◽  
1959 ◽  
Vol 29 (10) ◽  
pp. 777-782 ◽  
Author(s):  
THEODORE E. STERNE
Keyword(s):  
Planetary Atmosphere ◽  
Close Satellite

The motion of a lunar orbiter

1966 ◽  
Vol 25 ◽  
pp. 373
Author(s):  
Y. Kozai
Keyword(s):  
Degrees Of Freedom ◽  
Dimensional Space ◽  
Artificial Satellite ◽  
Equations Of Motion ◽  
Triaxial Ellipsoid ◽  
The Moon ◽  
Secular Motion ◽  
The Earth ◽  
Close Satellite ◽  
The Mean

The motion of an artificial satellite around the Moon is much more complicated than that around the Earth, since the shape of the Moon is a triaxial ellipsoid and the effect of the Earth on the motion is very important even for a very close satellite.The differential equations of motion of the satellite are written in canonical form of three degrees of freedom with time depending Hamiltonian. By eliminating short-periodic terms depending on the mean longitude of the satellite and by assuming that the Earth is moving on the lunar equator, however, the equations are reduced to those of two degrees of freedom with an energy integral.Since the mean motion of the Earth around the Moon is more rapid than the secular motion of the argument of pericentre of the satellite by a factor of one order, the terms depending on the longitude of the Earth can be eliminated, and the degree of freedom is reduced to one.Then the motion can be discussed by drawing equi-energy curves in two-dimensional space. According to these figures satellites with high inclination have large possibilities of falling down to the lunar surface even if the initial eccentricities are very small.The principal properties of the motion are not changed even if plausible values ofJ3andJ4of the Moon are included.This paper has been published in Publ. astr. Soc.Japan15, 301, 1963.

Error analysis for hyperbolic entry into planetary atmosphere

1989 ◽  
Author(s):  
JEAN KECHICHIAN
Keyword(s):  
Error Analysis ◽  
Planetary Atmosphere

scholarly journals GJ 436b and the stellar wind interaction: simulations constraints using Lyα and Hα transits

2020 ◽  
Author(s):  
Carolina Villarreal D’Angelo ◽  
Aline A Vidotto ◽  
Alejandro Esquivel ◽  
Gopal Hazra ◽  
Allison Youngblood
Keyword(s):  
Mass Loss ◽  
Stellar Wind ◽  
Planetary System ◽  
Neutral Hydrogen ◽  
Hydrogen Atmosphere ◽  
Planetary Atmosphere ◽  
Hydrodynamic Simulations ◽  
Stellar Disc ◽  
Planetary Mass ◽  
Best Fit

Abstract The GJ 436 planetary system is an extraordinary system. The Neptune-size planet that orbits the M3 dwarf revealed in the Lyα line an extended neutral hydrogen atmosphere. This material fills a comet-like tail that obscures the stellar disc for more than 10 hours after the planetary transit. Here, we carry out a series of 3D radiation hydrodynamic simulations to model the interaction of the stellar wind with the escaping planetary atmosphere. With these models, we seek to reproduce the $\sim 56\%$ absorption found in Lyα transits, simultaneously with the lack of absorption in Hα transit. Varying the stellar wind strength and the EUV stellar luminosity, we search for a set of parameters that best fit the observational data. Based on Lyα observations, we found a stellar wind velocity at the position of the planet to be around [250-460] km s−1 with a temperature of [3 − 4] × 105 K. The stellar and planetary mass loss rates are found to be 2 × 10−15 M⊙ yr−1 and ∼[6 − 10] × 109 g s−1, respectively, for a stellar EUV luminosity of [0.8 − 1.6] × 1027 erg s−1. For the parameters explored in our simulations, none of our models present any significant absorption in the Hα line in agreement with the observations.

scholarly journals Direct observation of long-lived cyanide anions in superexcited states

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Xiao-Fei Gao ◽  
Jing-Chen Xie ◽  
Hao Li ◽  
Xin Meng ◽  
Yong Wu ◽  
...  
Keyword(s):  
Direct Observation ◽  
Electron Attachment ◽  
Planetary Atmosphere ◽  
Interstellar Space ◽  
Dissociative Electron Attachment ◽  
Circumstellar Envelopes ◽  
Vibrational States ◽  
Cyanide Anion ◽  
Exceptional Stability ◽  
Electronic Ground

AbstractThe cyanide anion (CN−) has been identified in cometary coma, interstellar medium, planetary atmosphere and circumstellar envelopes, but its origin and abundance are still disputed. An isolated CN− is stabilized in the vibrational states up to ν = 17 of the electronic ground-state 1Σ+, but it is not thought to survive in the electronic or vibrational states above the electron autodetachment threshold, namely, in superexcited states. Here we report the direct observation of long-lived CN− yields of the dissociative electron attachment to cyanogen bromide (BrCN), and confirm that some of the CN− yields are distributed in the superexcited vibrational states ν ≥ 18 (1Σ+) or the superexcited electronic states 3Σ+ and 3Π. The triplet state can be accessed directly in the impulsive dissociation of BrCN− or by an intersystem transition from the superexcited vibrational states of CN−. The exceptional stability of CN− in the superexcited states profoundly influences its abundance and is potentially related to the production of other compounds in interstellar space.

Collisionless Hydrodynamic Generators in a Planetary Atmosphere

2014 ◽  
pp. 53-86
Author(s):  
Michael C. Kelley
Keyword(s):  
Planetary Atmosphere

scholarly journals Stellar activity and magnetic shielding

2009 ◽  
Vol 5 (S264) ◽  
pp. 385-394 ◽  
Author(s):  
J.-M. Grießmeier ◽  
M. Khodachenko ◽  
H. Lammer ◽  
J. L. Grenfell ◽  
A. Stadelmann ◽  
...  
Keyword(s):  
Dipole Moment ◽  
Magnetic Dipole ◽  
Magnetic Dipole Moment ◽  
Direct Interaction ◽  
Planetary Atmosphere ◽  
Stellar Activity ◽  
Planetary Environment ◽  
Atmospheric Loss ◽  
Planetary Magnetic Field ◽  
Planetary Habitability

AbstractStellar activity has a particularly strong influence on planets at small orbital distances, such as close-in exoplanets. For such planets, we present two extreme cases of stellar variability, namely stellar coronal mass ejections and stellar wind, which both result in the planetary environment being variable on a timescale of billions of years. For both cases, direct interaction of the streaming plasma with the planetary atmosphere would entail servere consequences. In certain cases, however, the planetary atmosphere can be effectively shielded by a strong planetary magnetic field. The efficiency of this shielding is determined by the planetary magnetic dipole moment, which is difficult to constrain by either models or observations. We present different factors which influence the strength of the planetary magnetic dipole moment. Implications are discussed, including nonthermal atmospheric loss, atmospheric biomarkers, and planetary habitability.

scholarly journals Transmission spectroscopy of HAT-P-32b with the LBT: confirmation of clouds/hazes in the planetary atmosphere

2016 ◽  
Vol 590 ◽  
pp. A100 ◽  
Author(s):  
M. Mallonn ◽  
K. G. Strassmeier
Keyword(s):  
Planetary Atmosphere ◽  
Transmission Spectroscopy

scholarly journals Near-ultraviolet transit photometry of HAT-P-32 b with the Large Binocular Telescope: Silicate aerosols in the planetary atmosphere

2017 ◽  
Vol 338 (7) ◽  
pp. 773-780 ◽  
Author(s):  
Matthias Mallonn ◽  
Hannah R. Wakeford
Keyword(s):  
Planetary Atmosphere ◽  
Near Ultraviolet
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