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Monthly Notices of the Royal Astronomical SocietyThese images of Neptune were captured by the Voyager 2 spacecraft in 1989. The images are accompanied by a brief description and history, some statistical facts, and importants dates in the study of Neptune.
E. J. Cooper, A. Graham
core +21 more sources
Empirical Structure Models of Uranus and Neptune [PDF]
Monthly notices of the Royal Astronomical Society, 2022 Uranus and Neptune are still poorly understood. Their gravitational fields, rotation periods, atmosphere dynamics, and internal structures are not well determined. In this paper we present empirical structure models of Uranus and Neptune where the density profiles are represented by polytropes.
Benno A. Neuenschwander, R. Helled
arxiv +3 more sources
Nature, 1885 SEVERAL circumstances delayed my observation of the planet Neptune this autumn until November 24. On that and the two following nights the light of Neptune was compared with the light of the star B.A.C. 1072; and, assuming that the light of the star was steady, that of Neptune was found to undergo apparently regular variations, but much smaller than ...
MAXWELL HALL
openalex +5 more sources
The Intrinsic Neptune Trojan Orbit Distribution: Implications for the Primordial Disk and Planet Migration [PDF]
, 2014 The present-day orbit distribution of the Neptune Trojans is a powerful probe of the dynamical environment of the outer solar system during the late stages of planet migration. In this work, I conservatively debias the inclination, eccentricity, and libration amplitude distributions of the Neptune Trojans by reducing a priori unknown discovery and ...
Parker, Alex H.
arxiv +3 more sources
Assessing the contribution of Centaur impacts to ice giant luminosities [PDF]
, 2015 Voyager 2 observations revealed that the internal luminosity of Neptune is an order of magnitude higher than that of Uranus. If the two planets have similar interior structures and cooling histories, the luminosity of Neptune can only be explained by invoking some energy source beyond gravitational contraction.
Dodson-Robinson, Sarah E.
arxiv +3 more sources
An ultrahot Neptune in the Neptune desert [PDF]
Nature Astronomy, 2020 About one out of 200 Sun-like stars has a planet with an orbital period shorter than one day: an ultra-short-period planet (Sanchis-ojeda et al. 2014; Winn et al. 2018). All of the previously known ultra-short-period planets are either hot Jupiters, with sizes above 10 Earth radii (Re), or apparently rocky planets smaller than 2 Re.
Michael Vezie +89 more
openaire +8 more sources
Origin and Dynamical Evolution of Neptune Trojans - I: Formation and Planetary Migration [PDF]
Mon.Not.Roy.Astron.Soc.398: 1715-1729,2009, 2009 We present the results of detailed dynamical simulations of the effect of the migration of the four giant planets on both the transport of pre-formed Neptune Trojans, and the capture of new Trojans from a trans-Neptunian disk. We find that scenarios involving the slow migration of Neptune over a large distance (50Myr to migrate from 18.1AU to its ...
B. W. Jones +48 more
arxiv +5 more sources
The formation of mini-Neptunes [PDF]
The Astrophysical Journal, 2017 Mini-Neptunes seem to be common planets. In this work we investigate the possible formation histories and predicted occurrence rates of mini-Neptunes assuming the planets form beyond the iceline. We consider pebble and planetesimal accretion accounting for envelope enrichment and two different opacity conditions.
Venturini, Julia, Helled, Ravit
arxiv +6 more sources
What do we Really Know about Uranus and Neptune? [PDF]
, 2012 The internal structures and compositions of Uranus and Neptune are not well constrained due to the uncertainty in rotation period and flattening, as well as the relatively large error bars on the gravitational coefficients. While Uranus and Neptune are similar in mass and radius, they differ in other physical properties such as thermal emission ...
Boué +9 more
arxiv +3 more sources
Uranus and Neptune: Shape and Rotation [PDF]
, 2010 Both Uranus and Neptune are thought to have strong zonal winds with velocities of several hundred meters per second. These wind velocities, however, assume solid-body rotation periods based on Voyager 2 measurements of periodic variations in the planets' radio signals and of fits to the planets' magnetic fields; 17.24h and 16.11h for Uranus and Neptune,
Anderson +29 more
arxiv +4 more sources