Results 51 to 60 of about 6,825 (205)

Sub-pixel Spectral Reduction Algorithm for Echelle Spectrometer [PDF]

open access: yes, 2021
Abstract A sub-pixel spectral reduction algorithm for the echelle spectrometer is proposed here to ensure a high spectral resolution for it. The initial model is established by separating cross-dispersion and calculating the imaging offset from the center.
JIN YANG   +5 more
openaire   +1 more source

Commissioning an Inexpensive Off‐The‐Shelf Spectrograph for Radial‐Velocity Studies

open access: yesAstronomische Nachrichten, Volume 347, Issue 2, February 2026.
ABSTRACT We present a way to set up an inexpensive out of the shelf spectrograph at a local observatory. Stability and resolution of the spectrograph are high enough for radial velocity determination of binary stars or determination of stellar characteristics. Even some exoplanets might be detectable via the radial velocity method.
Lukas Stock, Andreas Schrimpf
wiley   +1 more source

THE OPTICAL HIGH-RESOLUTION SPECTROSCOPY AS A METHOD OF X-RAY BINARY CYG X-1 INVESTIGATION

open access: yesOdessa Astronomical Publications, 2017
Recently a lot of photometric effects were revealed during the investigation of the first can- didate to black hole Cyg X-1. Besides of orbital vari- ations different kinds of flares, so-called precession period 147/294 days and a significant correlation
E. A. Karitskaya   +5 more
doaj   +1 more source

The Kepler Giant Planet Search. I. A Decade of Kepler Planet-host Radial Velocities from W. M. Keck Observatory

open access: yesThe Astrophysical Journal Supplement Series, 2023
Despite the importance of Jupiter and Saturn to Earth’s formation and habitability, there has not yet been a comprehensive observational study of how giant exoplanets correlate with the architectural properties of close-in, sub-Neptune-sized exoplanets ...
Lauren M. Weiss   +21 more
doaj   +1 more source

Optical System Design of an Echelle Spectrometer Based on a Digital Micromirror Device

open access: yesOptics
The echelle spectrometer utilizes an echelle grating as the primary dispersive element, combined with a prism or planar grating for cross-dispersion, to form a two-dimensional spectral image on an area-array Charge-Coupled Device (CCD).
Jia Liu   +5 more
doaj   +1 more source

The Great Cold Spot in Jupiter's upper atmosphere

open access: yesGeophysical Research Letters, 2017
Past observations and modeling of Jupiter's thermosphere have, due to their limited resolution, suggested that heat generated by the aurora near the poles results in a smooth thermal gradient away from these aurorae, indicating a quiescent and diffuse ...
Tom S. Stallard   +10 more
doaj   +1 more source

Water Vapor Vertical Distribution on Mars After Six Years of TGO/NOMAD Solar Occultations: 1. Global Climatology

open access: yesJournal of Geophysical Research: Planets, Volume 131, Issue 2, February 2026.
Abstract We present vertical profiles of water vapor obtained during six continuous years of solar occultation observations in the infrared by the Nadir and Occultation for MArs Discovery (NOMAD) instrument on board Trace Gas Orbiter. The retrievals have been performed with an inversion code previously applied to smaller samples of this data set, but ...
A. Brines   +20 more
wiley   +1 more source

The planet search program at the ESO Coudé Echelle spectrometer [PDF]

open access: yesAstronomy & Astrophysics, 2001
In this article we present the results of the planet search program carried out at the ESO Coude Echelle Spectrometer (CES) for components A and B of the α Centauri system. Since November 1992 we have obtained high precision differential radial velocities (RV s) for both stars.
M. Endl   +4 more
openaire   +1 more source

Water Vapor Vertical Distribution on Mars After Six Years of TGO/NOMAD Solar Occultations: 2. Cross‐Validation Within TGO and Comparison With MPCM

open access: yesJournal of Geophysical Research: Planets, Volume 131, Issue 2, February 2026.
Abstract This is the second part of an investigation of water vapor in the Martian atmosphere using solar occultation observations by the Nadir and Occultation for MArs Discovery (NOMAD) spectrometer on board the ExoMars Trace Gas Orbiter. Following the analysis of six Earth years of NOMAD observations performed in the first part, a cross‐validation ...
A. Brines   +19 more
wiley   +1 more source

An arbuscular mycorrhiza from the 407‐million‐year‐old Windyfield Chert identified through advanced fluorescence and Raman imaging

open access: yesNew Phytologist, Volume 249, Issue 1, Page 448-459, January 2026.
Summary Mycorrhizal associations between fungi and plants are a fundamental aspect of terrestrial ecosystems. Mycorrhizas occur in c. 85% of extant plants, yet their geological record remains sparse. Rare fossil evidence from early terrestrial environments offers crucial insights into these ancient symbioses, but visualizing fossil fungi at the ...
Christine Strullu‐Derrien   +7 more
wiley   +1 more source

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