Results 21 to 30 of about 927 (113)

OGLE-2019-BLG-1180Lb: Discovery of a Wide-orbit Jupiter-mass Planet around a Late-type Star

open access: yesThe Astronomical Journal, 2023
We report on the discovery and analysis of the planetary microlensing event OGLE-2019-BLG-1180 with a planet-to-star mass ratio q ∼ 0.003. The event OGLE-2019-BLG-1180 has unambiguous cusp-passing and caustic-crossing anomalies, which were caused by a ...
Sun-Ju Chung   +35 more
doaj   +1 more source

Detecting Multiplanetary Systems with Gravitational Microlensing and the Roman Space Telescope

open access: yesThe Astronomical Journal, 2023
It is plausible that most of the Stars in the Milky Way Galaxy, like the Sun, consist of planetary systems, instead of a single planet. Out of the estimately discovered 3980 planet-hosting stars, about 860 of them are known to be multiplanetary systems ...
Hossein Fatheddin, Sedighe Sajadian
doaj   +1 more source

Gravitational Lensing of Charged Ayon‐Beato‐Garcia Black Holes and Nonlinear Effects of Maxwell Fields

open access: yesAdvances in High Energy Physics, Volume 2018, Issue 1, 2018., 2018
Nonsingular Ayon‐Beato‐Garcia (ABG) spherically symmetric static black hole (BH) with charge to mass ratio q = g/2m is metric solution of Born Infeld nonlinear Maxwell‐Einstein theory. Central region of the BH behaves as (anti‐)de Sitter for (|q | > 1) | q | < 1.
H. Ghaffarnejad   +3 more
wiley   +1 more source

Bose‐Einstein Condensate Dark Matter Halos Confronted with Galactic Rotation Curves

open access: yesAdvances in High Energy Physics, Volume 2017, Issue 1, 2017., 2017
We present a comparative confrontation of both the Bose‐Einstein Condensate (BEC) and the Navarro‐Frenk‐White (NFW) dark halo models with galactic rotation curves. We employ 6 High Surface Brightness (HSB), 6 Low Surface Brightness (LSB), and 7 dwarf galaxies with rotation curves falling into two classes.
M. Dwornik   +4 more
wiley   +1 more source

Possibility of Detection of Exomoons with Inclined Orbits Orbiting Pulsar Planets Using the Time‐of‐Arrival Analysis

open access: yesAdvances in Astronomy, Volume 2014, Issue 1, 2014., 2014
The perturbation caused by planet‐moon binarity on the time‐of‐arrival (TOA) signal of a pulsar with an orbiting planet is derived for the case of the orbit of the planet‐moon system inclined of an angle α with respect to the plane of the orbit of the planet‐moon barycenter around the pulsar.
Antonio Pasqua   +2 more
wiley   +1 more source

Astronomical Signatures of Dark Matter

open access: yesAdvances in High Energy Physics, Volume 2014, Issue 1, 2014., 2014
Several independent astronomical observations in different wavelength bands reveal the existence of much larger quantities of matter than what we would deduce from assuming a solar mass to light ratio. They are very high velocities of individual galaxies within clusters of galaxies, higher than expected rotation rates of stars in the outer regions of ...
Paul Gorenstein   +2 more
wiley   +1 more source

The gravitational microlens influence on X-ray spectral line generated by an AGN accretion disc [PDF]

open access: yesSerbian Astronomical Journal, 2001
The influence of gravitational microlensing on the X-ray spectral line profiles originated from a relativistic accretion disc has been studied. Using a disc model, we show that microlensing can induce noticeable changes in the line shapes when the ...
Popović L.Č.   +4 more
doaj   +1 more source

Die Suche nach kalten, fremden Welten

open access: yesPhysik in unserer Zeit, Volume 55, Issue 3, Page 140-147, May 2024.
Die meisten der heute bekannten extrasolaren Planeten umkreisen ihren Mutterstern auf engen Umlaufbahnen in weniger als 100 Tagen. Gesteinsplaneten mit größeren Bahnradien sind von herausragender Bedeutung für Theorien der Planetenentstehung. Die Mikrogravitationslinsenmethode bietet eine hervorragende Möglichkeit, solche Planeten zu finden – und das ...
Markus Hundertmark, Yiannis Tsapras
wiley   +1 more source

Dark Matter Halos from the Inside Out

open access: yesAdvances in Astronomy, Volume 2011, Issue 1, 2011., 2011
The balance of evidence indicates that individual galaxies and groups or clusters of galaxies are embedded in enormous distributions of cold, weakly interacting dark matter. These dark matter “halos” provide the scaffolding for all luminous structures in the universe, and their properties comprise an essential part of the current cosmological model.
James E. Taylor, Rob Ivison
wiley   +1 more source

Dark Matter: A Primer

open access: yesAdvances in Astronomy, Volume 2011, Issue 1, 2011., 2011
Dark matter is one of the greatest unsolved mysteries in cosmology at the present time. About 80% of the Universe′s gravitating matter is nonluminous, and its nature and distribution are for the most part unknown. In this paper, we will outline the history, astrophysical evidence, candidates, and detection methods of dark matter, with the goal to give ...
Katherine Garrett   +2 more
wiley   +1 more source

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