Results 31 to 40 of about 1,548 (142)

Why Machine Learning Models Systematically Underestimate Extreme Values

The Open Journal of Astrophysics
A persistent challenge in astronomical machine learning is a systematic bias where predictions compress the dynamic range of true values---high values are consistently predicted too low while low values are predicted too high. Understanding this bias has
Yuan-Sen Ting
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A High-resolution Non-detection of Escaping Helium in the Ultrahot Neptune LTT 9779b: Evidence for Weakened Evaporation

The Astrophysical Journal Letters
The recent discovery of “ultrahot” ( P < 1 day) Neptunes has come as a surprise: some of these planets have managed to retain gaseous envelopes despite being close enough to their host stars to trigger strong photoevaporation and/or Roche lobe overflow ...
Shreyas Vissapragada, Patrick McCreery, Leonardo A. Dos Santos, Néstor Espinoza, Andrew McWilliam, Noriyuki Matsunaga, Jéa Adams Redai, Patrick Behr, Kevin France, Satoshi Hamano, Charlie Hull, Yuji Ikeda, Haruki Katoh, Hideyo Kawakita, Mercedes López-Morales, Kevin N. Ortiz Ceballos, Shogo Otsubo, Yuki Sarugaku, Tomomi Takeuchi   +18 more
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ASTRONOMICAL GLASS PLATE NEGATIVES: MONITORING OF EMULSION LAYER DETERIORATION

Acta Polytechnica, 2016
One of the techniques for making photographic negatives most used in the history of photography were gelatin glass plates. This technique was used not only in the artistic field but also and mainly in the scientific field.
L. Miskova, P. Novák, R. Hudec, M. Novotná   +3 more
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Overview of the Fiber System for the Dark Energy Spectroscopic Instrument

The Astronomical Journal
The Dark Energy Spectroscopic Instrument (DESI) is a revolutionary instrument designed for precise measurements of cosmic distances and the investigation of dark energy.
Claire Poppett, Luke Tyas, J. Aguilar, Christopher Bebek, D. Bramall, T. Claybaugh, J. Edelstein, P. Fagrelius, H. Heetderks, P. Jelinsky, S. Jelinsky, Robin Lafever, A. Lambert, M. Lampton, Michael E. Levi, P. Martini, C. Rockosi, J. Schmoll, Ray M. Sharples, Martin Sirk, Edward Wishnow, Jiaxi Yu, S. Ahlen, A. Bault, S. BenZvi, D. Brooks, S. Cole, A. de la Macorra, Arjun Dey, P. Doel, K. Fanning, A. Font-Ribera, J. E. Forero-Romero, E. Gaztañaga, S. Gontcho A Gontcho, A. X. Gonzalez-Morales, C. Hahn, K. Honscheid, J. Jimenez, S. Juneau, D. Kirkby, A. Kremin, M. Landriau, L. Le Guillou, M. Manera, A. Meisner, R. Miquel, J. Moustakas, E. Mueller, A. Muñoz-Gutiérrez, A. D. Myers, J. Nie, G. Niz, N. Palanque-Delabrouille, W. J. Percival, F. Prada, D. Rabinowitz, M. Rezaie, G. Rossi, E. Sanchez, Edward F. Schlafly, D. Schlegel, M. Schubnell, H. Seo, D. Sprayberry, G. Tarlé, M. Vargas-Magaña, B. A. Weaver, R. Zhou   +68 more
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The Top Ten Astronomical 'breakthroughs' of the 20th century

Communicating Astronomy with the Public Journal, 2007
Astronomy was revolutionized in the 20th century. The electron was discovered in 1897 and this transformed spectroscopy and introduced plasma and magnetohydrodynamic physics and astro-chemistry.
Hughes, D. W., de Grijs, Richard
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The New SDSS 2.5 m Telescope Wide-field Corrector for SDSS-V

The Astronomical Journal
SDSS-V is the fifth generation of the Sloan Digital Sky Survey and is an ambitious follow-up to a project that has been producing ground-breaking science for more than two decades.
Stephen A. Smee, Robert H. Barkhouser, Randolph P. Hammond, Albert C. Harding, Aidan C. Gray, Solange Ramirez, Stefanie Wachter, Juna Kollmeier, John Downey, Jamey E. Eriksen, Dmitry Bizyaev, Dylan Gatlin, Katie Grabowski, Karen Kinemuchi, Daniel Oravetz, Audrey Oravetz, Dan Long, Viktor Malanushenko, Fred Mrozek, Tracy Naugle, Kaike Pan, Ryan Wagner, John C. Wilson   +22 more
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Cavity ring down spectroscopy of cold neutral phenanthrene and phenanthridine in supersonic jets

AIP Advances, 2019
Here we study the effect of nitrogen insertion on the electronic spectra of polycyclic aromatic hydrocarbon (PAH) molecules measured under laboratory conditions that are relevant for comparison with astronomical data.
Salma Bejaoui, Farid Salama
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The Hearth of the World: The Sun before Astrophysics

Universe
This paper presents a historical overview of conceptions about the Sun in Western astronomical and cosmological traditions before the advent of spectroscopy and astrophysics. Rather than studying general cultural ideas, we focus on the concepts developed
Gábor Kutrovátz
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Dual-comb precision calibration of an astronomical Fabry–Pérot cavity [PDF]

APL Photonics
Astronomical precision spectroscopy supports searches for exoplanets and may enable the direct observation of the Universe’s expansion. A key challenge in these efforts is the precise and long-term calibration of astronomical spectrographs.
Thibault Voumard, Thibault Wildi, Markus Ludwig, François Bouchy, Tobias Herr   +4 more
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First Results from WINERED: Detection of Emission Lines from Neutral Iron and a Combined Set of Trace Species on the Dayside of WASP-189 b

The Astronomical Journal
Ground- and space-based observations have revealed that ultrahot Jupiters (UHJs, T _eq  > 2200 K) typically have inverted thermal profiles, while cooler hot Jupiters have noninverted ones.
Lennart van Sluijs, Emily Rauscher, Eliza M.-R. Kempton, Thomas Kennedy, Isaac Malsky, Noriyuki Matsunaga, Michael Meyer, Andrew McWilliam, John D. Monnier, Shogo Otsubo, Yuki Sarugaku, Tomomi Takeuchi   +11 more
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