Search Publications
Identification of additional young nearby runaway stars based on Gaia data release 2 observations and the lithium test
Torres, Guillermo; Mugrauer, Markus; Michel, Kai-Uwe +4 more
Runaway stars are characterized by their remarkably high space velocities, and the study of their formation mechanisms has attracted considerable interest. Young, nearby runaway stars are the most favorable for identifying their place of origin, and for searching for possible associated objects such as neutron stars. Usually, the research field of…
Identifying Circumgalactic Medium Absorption in QSO Spectra: A Bayesian Approach
Scott, Jennifer E.; Shoemaker, Emileigh S.; Hamill, Colin D.
We present a study of candidate galaxy-absorber pairs for 43 low-redshift QSO sightlines (0.06 < z < 0.85) observed with the Hubble Space Telescope/Cosmic Origins Spectrograph that lie within the footprint of the Sloan Digital Sky Survey with a statistical approach to match absorbers with galaxies near the QSO lines of sight using only the S…
‘Campfires’ may drive heating of solar atmosphere
Clery, Daniel
Researchers are getting closer to solving the mystery of why the Sun's wispy atmosphere is nearly 200 times hotter than its surface. Temperatures ought to decline as one moves out from the Sun's core, but the solar atmosphere, or corona, seethes at more than 1 million degrees Celsius, far hotter than the 5500°C temperature of the surface. Flares h…
UVIT-HST-Gaia-VISTA study of Kron 3 in the Small Magellanic Cloud: a cluster with an extended red clump in ultraviolet
Cioni, Maria-Rosa L.; Chung, Chul; Bell, Cameron P. M. +6 more
We have demonstrated the advantage of combining multiwavelength observations, from the ultraviolet (UV) to near-infrared, to study Kron 3, a massive star cluster in the Small Magellanic Cloud. We have estimated the radius of the cluster Kron 3 to be 2.0 arcmin and for the first time, we report the identification of NUV-bright red clump (RC) stars …
Reduced Microwave Brightness Temperature in a Sunspot Atmosphere Due to Open Magnetic Fields
White, S. M.; Vrublevskis, A.; Ryabov, B. I.
Motivated by dark coronal lanes in 284 Å extreme-ultraviolet (EUV) observations from the Extreme-ultraviolet Imaging Telescope on board the Solar and Heliospheric Observatory (SOHO/EIT), we construct and optimize an atmosphere model of the active region (AR) 8535 sunspot by adding a cool and dense component in the volume of plasma along open field…
Estimation of ages and masses via carbon and nitrogen abundances for 556 007 giants from LAMOST
Zhao, Gang; Buder, Sven; Wu, Ya-Qian +1 more
Estimating ages for a large number of giants is of great importance for studying Galactic evolution. In this work, we determine stellar ages and masses for 556 007 giants from LAMOST Data Release 5 (DR5) with empirical relations estimated from chemical [C/N] abundance ratios. Our sample reveals the two well-known sequences in the age-[α/M] relatio…
MG1-688432: A Peculiar Variable System
Corbally, Christopher J.; Kraus, Adam L.; Tucker, Roy A. +3 more
The short-period variable star MG1-688432 has been discovered to exhibit occasional extremely high energy optical outbursts as high as 1038 erg. Outbursts are typically several hours in duration. These events are often highly structured, resembling sequential associated releases of energy. Twenty years of time sequence photometry are pr…
New Spectral Analysis Results Within the Scope of Extended Matter Research in the AR Lacertae Active Binary System
Ekmekçi, F.; Karakuş, O.
Within the scope of extended matter research, we present new spectral analysis results of an active binary system, AR Lac. The low and high resolution spectra of this system, were taken during the period 2013-2016. The evaluation of low dispersion spectra together with the B, V, Rc, Ic and WISE photometric data showed that AR…
Characterizing Magnetic Connectivity of Solar Flare Electron Sources to STEREO Spacecraft Using ADAPT-WSA Modeling
Arge, C. N.; Henney, C. J.; Kahler, S. W. +1 more
Onsets and intensity profiles of six energetic (E > 30 keV) electron events common to STEREO A and B (STA and STB) spacecraft were analyzed by Klassen et al. with the STEREO Solar Electron and Proton Telescopes when the spacecraft were separated by <70° in solar longitude. All six events were characterized by earlier onsets and higher peak i…
An empirical model of energetic electrons in Saturn's magnetosphere based on Cassini data
Zhang, Lei; Wang, Jian-zhao; Huo, Zhuo-xi
Based on one-hour average data observed by the MIMI/LEMMS instrument onboard the Cassini spacecraft from 2004 to 2017, we present an empirical model of energetic electrons (27 keV-1937 keV) in Saturn's magnetosphere. This model distinguishes between two different regions. In the inner magnetosphere (<20RS, RS = 60268 km is…