Results 31 to 40 of about 53,340 (257)
Journal of Geophysical Research: Planets, Volume 128, Issue 12, December 2023., 2023 Abstract We use a long‐term record of ground‐based mid‐infrared (7.9–24.5 μm) observations, captured between 1984 and late 2019 from 3‐m and 8‐m class observatories (mainly NASA's Infrared Telescope Facility, ESO's Very Large Telescope, and the Subaru Telescope), to characterize the long‐term, multi‐decade variability of the thermal and aerosol ...
Arrate Antuñano +9 more
wiley +1 more source
The properties of field elliptical galaxies at intermediate redshift - II. Photometry and spectroscopy of anHST-selected sample [PDF]
Monthly Notices of the Royal Astronomical Society, 2001 A sample of field early-type galaxies (E/S0) at intermediate redshift ($z\sim0.1-0.6$) is selected, based on morphology and colours from HST-WFPC2 parallel images. Photometric structural parameters (effective radius $R_{\tx{e}}$ and effective surface brightness $SB_{\tx{e}}$) are derived through the F606W and F814W filters, using luminosity profile ...
Tommaso Treu +4 more
openalex +7 more sources
Journal of Geophysical Research: Planets, Volume 128, Issue 12, December 2023., 2023 Abstract Spectroscopic measurements are a powerful tool to investigate the surface composition of airless bodies and provide clues of their origin. The composition and origin of Phobos and Deimos are still unknown and are currently widely debated. We present spectroscopic measurements of Phobos and Deimos at ultraviolet and visible wavelengths (250–650
J. P. Mason +20 more
wiley +1 more source
deepCR on ACS/WFC: Cosmic-Ray Rejection for HST ACS/WFC Photometry
Research Notes of the AAS, 2021 Abstract deepCR is a deep-learning-based cosmic-ray rejection algorithm previously demonstrated to be superior to state-of-the-art LACosmic on Hubble Space Telescope (HST) Advanced Camera for Surveys (ACS)/WFC F606W imaging data. In this research note, we present a new deepCR model for use on all filters of HST ACS/WFC.
K. J. Kwon, Keming Zhang, J. S. Bloom
openalex +3 more sources
The Astrophysical Journal Supplement Series, 2022 We present a near-complete catalog of the metal-rich population of thermally pulsing asymptotic giant branch (AGB) stars in the northwest quadrant of M31.
Steven R. Goldman +7 more
doaj +1 more source
A brief history of image sensors in the optical
Astronomische Nachrichten, Volume 344, Issue 8-9, October-November 2023., 2023 Image sensors, most notably the Charge Coupled Device (CCD), have revolutionized observational astronomy as perhaps the most important innovation after photography. Since the 50th anniversary of the invention of the CCD has passed in 2019, it is time to review the development of detectors for the visible wavelength range, starting with the discovery of
Martin M. Roth
wiley +1 more source
Photometry and astrometry with JWST‐II: NIRCam distortion correction
Astronomische Nachrichten, Volume 344, Issue 3, March 2023., 2023 Abstract In preparation to make the most of our own planned James Webb Space Telescope investigations, we take advantage of publicly available calibration and early‐science observations to independently derive and test a geometric‐distortion solution for NIRCam detectors. Our solution is able to correct the distortion to better than ∼$$ \sim $$0.2 mas.
M. Griggio, D. Nardiello, L. R. Bedin
wiley +1 more source
The harsh environment where exoplanets live
Astronomische Nachrichten, Volume 343, Issue 4, May 2022., 2022 Abstract The X‐ray and Extreme Ultraviolet (XUV) actvity of the Sun has determined important effects on the planets around it. In particular, high doses of X‐rays, flares, and coronal mass ejections (CMEs) combined with masses and sizes of the planets and the shielding action of the planetary magnetic fields have determined the diverse habitability of ...
Ignazio Pillitteri
wiley +1 more source
HST photometry of Globular Clusters in the Sombrero Galaxy [PDF]
Monthly Notices of the Royal Astronomical Society, 2001 We explore the rich globular cluster (GC) system of the nearby Sa galaxy M104, the "Sombrero" (NGC 4594), using archive WFPC2 data. The GC colour distribution is found to be bimodal at the > 99% level, with peaks at V-I = 0.96+/-0.03 and 1.21+/-0.03 (corrected for foreground reddening).
Soeren S. Larsen +2 more
openalex +6 more sources
HST Photometry of 47 Tucanae: Time Series Analysis and Search for Giant Planets [PDF]
Symposium - International Astronomical Union, 2004 Gilliland et al. (2000) have reported HST photometric observations of 34000 stars in the globular cluster 47 Tuc, showing an absence of close-in giant planets in that cluster relative to their frequency in the solar neighborhood. Here we describe the methods of time-series analysis that were used to search the 47 Tuc data for transits by giant ...
Timothy M. Brown +22 more
openalex +3 more sources