Search Publications
Discrete Element Modeling of Aeolian-like Morphologies on Comet 67P/Churyumov-Gerasimenko
Otto, K. A.; Sachse, M.; Kappel, D. +1 more
Context. Even after the Rosetta mission, some of the mechanical parameters of comet 67P/Churyumov-Gerasimenko's surface material are still not well constrained. They are needed to improve our understanding of cometary activity or for planning sample return procedures.
Aims: We discuss the physical process dominating the formation of aeolian-l…
Joint Survey Processing. II. Stellar Proper Motions in the COSMOS Field from Hubble Space Telescope ACS and Subaru Telescope HSC Observations
Fajardo-Acosta, Sergio B.; Faisst, Andreas; Grillmair, Carl J. +4 more
We analyze stellar proper motions in the COSMOS field to assess the presence of bulk motions. At bright magnitudes (G-band 18.5-20.76 AB), we use the proper motions of 1010 stars in the Gaia DR2 catalog. At the faint end, we compute proper motions of 11,519 pointlike objects at i-band magnitudes 19-25 AB using Hubble ACS and Subaru HSC data, which…
Color Dependence of the Transit Detectability of Young Active M Dwarfs
Gaidos, Eric; Miyakawa, Kohei; Hirano, Teruyuki +2 more
We investigate the planetary transit detectability in the presence of stellar rotational activity from light curves of young M dwarfs, and estimate the improvements in detection at near-infrared (NIR) wavelengths. By making maps of the transit signal detection efficiency over the orbital period and planetary radius with light curves of the members…
Multi-scale image preprocessing and feature tracking for remote CME characterization
Stepanyuk, Oleg; Kozarev, Kamen; Nedal, Mohamed
Coronal Mass Ejections (CMEs) influence the interplanetary environment over vast distances in the solar system by injecting huge clouds of fast solar plasma and energetic particles (SEPs). A number of fundamental questions remain about how SEPs are produced, but current understanding points to CME-driven shocks and compressions in the solar corona…
Solid confirmation of the broad DIB around 864.8 nm using stacked Gaia-RVS spectra
Schultheis, M.; Marshall, D. J.; Smith, M. +26 more
Context. Studies of the correlation between different diffuse interstellar bands (DIBs) are important for exploring their origins. However, the Gaia-RVS spectral window between 846 and 870 nm contains few DIBs, the strong DIB at 862 nm being the only convincingly confirmed one.
Aims: Here we attempt to confirm the existence of a broad DIB aro…
Assessment of the accuracy of measures in the 1829 southern double star catalogue of James Dunlop
Letchford, Roderick R.; White, Graeme L.; Brown, Carolyn J.
In 1829 James Dunlop published the first southern double star catalogue of some 253 double stars. The accuracy of this catalogue has been determined by using Aladin to cross-match them with Gaia DR2 and estimate their positional (right ascension, declination, position angle, and separation) and magnitude accuracy. Seven per cent could not be ident…
Polarimetric Studies of a Fast Coronal Mass Ejection
Bemporad, Alessandro; Mierla, Marilena; Inhester, Bernd +4 more
In this work we performed a polarimetric study of a fast and wide coronal mass ejection (CME) observed on 12 July 2012 by the COR1 and COR2 instruments onboard the Solar TErrestrial RElations Observatory (STEREO) mission. The CME source region was an X1.4 flare located at approximately S15W01 on the solar disk, as observed from the Earth's perspec…
Fragmented atomic shell around S187 H II region and its interaction with molecular and ionized gas
Ghosh, Swarna K.; Dewangan, Lokesh K.; Ojha, Devendra K. +6 more
The environment of S187, a nearby H II region (1.4 ± 0.3 kpc), is analyzed. A surrounding shell has been studied in the H I line, molecular lines, and also in infrared and radio continua. We report the first evidence of a clumpy H I environment in its photodissociation region. A background radio galaxy enables the estimation of the properties of c…
Not That Simple: The Metallicity Dependence of the Wide Binary Fraction Changes with Separation and Stellar Mass
Niu, Zexi; Liu, Jifeng; Yuan, Haibo +1 more
The metallicity dependence of the wide binary fraction (WBF) is critical for studying the formation of wide binaries. While controversial results have been found in recent years, here we combine the wide binary catalog recognized from Gaia EDR3 and stellar parameters from LAMOST to investigate this topic. Taking the bias of the stellar temperature…
Photometric Correction of Images of Visible and Near-Infrared Bands from Chandrayaan-1 Hyper-Spectral Imager (HySI): HySI Photometric Correction
Lala, Mili Ghosh Nee; Bose, Subhadyouti; Krishna, Akhouri Pramod
Photometric correction is a necessary step in planetary image pre-processing since the images of planetary surfaces are acquired by orbiting spacecraft at various observational geometries. In this study, visible (748 nm) and near-infrared (948 nm) bands of Hyper Spectral Imager (HySI) onboard Chandrayaan-1 have been used to derive a preliminary ph…