Results 31 to 40 of about 8,488 (185)

The nature of B supergiants: clues from a steep drop in rotation rates at 22000 K. The possibility of Bi-stability braking [PDF]

, 2010
The location of B supergiants in the Hertzsprung-Russell diagram (HRD) represents a long-standing problem in massive star evolution. Here we propose their nature may be revealed utilising their rotational properties, and we highlight a steep drop in ...
Brott, I., de Koter, A., Graefener, G., Langer, N., Lennon, D. J., Vink, Jorick S.   +5 more
core   +2 more sources

Photometric Calibrations of M-dwarf Metallicity with Markov Chain Monte Carlo and Bayesian Inference

The Astrophysical Journal, 2023
Knowledge of stellar atmospheric parameters ( T _eff , $\mathrm{log}g$ , [Fe/H]) of M dwarfs can be used to constrain both theoretical stellar models and Galactic chemical evolutionary models, and guide exoplanet searches, but their determination is ...
C. Duque-Arribas, D. Montes, H. M. Tabernero, J. A. Caballero, J. Gorgas, E. Marfil   +5 more
doaj   +1 more source

The effects of gravity on the climate and circulation of a terrestrial planet

Quarterly Journal of the Royal Meteorological Society, Volume 145, Issue 723, Page 2627-2640, July 2019 Part B., 2019
The climate and circulation of a terrestrial planet are governed by many orbital and planetary parameters, but here we explore the effect of changing the Newtonian gravitational acceleration. We consider how radiative and dynamical processes are altered, with subsequent changes in water vapour found to be particularly important.
Stephen I. Thomson, Geoffrey K. Vallis
wiley   +1 more source

Star-Forming AGN Host Galaxies

, 2001
The symbiosis of nuclear activity and star-formation in galaxies, as manifested in their spectral energy distributions (SEDs) is reviewed. Attention is drawn to an Hertzsprung-Russell diagram-equivalent for such objects, as well as to the importance of ...
Bregman, Brown, Canalizo, Canalizo, Clements, Colina, Condon, Condon, De Grijp, Edelson, Giuricin, Golombek, Haas, Haas, Heckman, Heckman, Hes, Hoekstra, Impey, Kewley, Kirhakos, Klaas, Lutz, Lutz, Lutz, Madau, Mazzarella, Miley, Neugebauer, Neugebauer, Peter Barthel, Polletta, Pérez Garcı́a, Rodrı́guez Espinosa, Rodrı́guez Espinosa, Rowan-Robinson, Rush, Sanders, Sanders, Schinnerer, Schmidt, Shaver, Sopp, Spinoglio, Spoon, Taylor, Van Bemmel, Van Bemmel, Willott, Wink   +49 more
core   +3 more sources

Tracing the origin of neutron-capture elements in the metalpoor star HE 1244-3036 [PDF]

EPJ Web of Conferences
We present results from a detailed abundance analysis of a star HE 1244-3036, based on a high resolution (R ∼ 50000) SUBARU/HDS spectrum. The wavelength coverage is from 3510 to 5310 Å. Our estimated metallicity [Fe/H] ∼ −2.5 and carbon abundance ([C/Fe]
Dutta Debasish, Goswami Aruna
doaj   +1 more source

A Technique to Derive Improved Proper Motions for Kepler Objects of Interest [PDF]

, 2014
We outline an approach yielding proper motions with higher precision than exists in present catalogs for a sample of stars in the Kepler field. To increase proper motion precision we combine first moment centroids of Kepler pixel data from a single ...
Benedict, G. Fritz, Cargile, Phillip A., Ciardi, David R., Tanner, Angelle M.   +3 more
core   +4 more sources

Anomaly detection by robust statistics

WIREs Data Mining and Knowledge Discovery, Volume 8, Issue 2, March/April 2018., 2018
Fitting a line to data with outliers: classical (red) and robust (blue). Real data often contain anomalous cases, also known as outliers. These may spoil the resulting analysis but they may also contain valuable information. In either case, the ability to detect such anomalies is essential.
Peter J. Rousseeuw, Mia Hubert
wiley   +1 more source

Magneto-Convection and Lithium Age Estimates of the \beta Pictoris Moving Group

, 2010
Although the means of the ages of stars in young groups determined from Li depletion often agree with mean ages determined from Hertzsprung - Russell diagram isochrones, there are often statistically significant differences in the ages of individual ...
Barrado y Navascués, Browning, Browning, Burke, Böhm-Vitense, Chandrasekhar, Chaplin, Christensen-Dalsgaard, Cowling, D. J. Mullan, Feigelson, Gabriel, Gough, Günther, J. Macdonald, Jayawardhana, Lopez-Morales, MacDonald, MacDonald, Mentuch, Mihalas, Morales, Morales, Mullan, Mullan, Piau, Schröder, Song, Stauffer, Torres, Ventura, White, Yee, Zuckerman   +33 more
core   +1 more source

Quasi‐Normal Modes: The “Electrons” of Black Holes as “Gravitational Atoms”? Implications for the Black Hole Information Puzzle

Advances in High Energy Physics, Volume 2015, Issue 1, 2015., 2015
Some recent important results on black hole (BH) quantum physics concerning the BH effective state and the natural correspondence between Hawking radiation and BH quasi‐normal modes (QNMs) are reviewed, clarified, and refined. Such a correspondence permits one to naturally interpret QNMs as quantum levels in a semiclassical model. This is a model of BH
Christian Corda, Maxim Khlopov
wiley   +1 more source

PERICLES: A Set of Empirical Rotational Isochrones Modeled on Cool Dwarfs in Open Clusters and Wide Binaries

Astronomische Nachrichten, Volume 347, Issue 1, January 2026.
ABSTRACT Isochrones, equal‐age curves, are widely used in astrophysics to estimate stellar ages. Classical stellar parameters are, however, very limited in their usability for main sequence stars because of their weak age‐dependence. Here, rotation period measurements provide complementary information.
David Gruner, Sydney A. Barnes
wiley   +1 more source