Search Publications
Multiple Stellar Populations of Globular Clusters from Homogeneous Ca-CN-CH-NH Photometry. VII. Metal-poor Populations in 47 Tucanae (NGC 104)
Lee, Jae-Woo
We present new large field-of-view (~1°×1°) Ca-CN photometry of the prototypical metal-rich globular cluster 47 Tucanae (NGC 104). Our results are the following. (1) The populational number ratios of the red giant branch (RGB) and red horizontal branch (RHB) are in excellent agreement: n(CN-w):n(CN-s) = 30:70 (±1-2), where the CN-w and CN-s stand …
Observations of a Flare-ignited Broad Quasiperiodic Fast-propagating Wave Train
Liu, Ying D.; Hu, Huidong; Shen, Yuandeng +6 more
Large-scale extreme-ultraviolet (EUV) waves are frequently observed as an accompanying phenomenon of flares and coronal mass ejections (CMEs). Previous studies mainly focused on EUV waves with single wave fronts that are generally thought to be driven by the lateral expansion of CMEs. Using high spatiotemporal resolution multi-angle imaging observ…
Variable Stars in the Giant Satellite Galaxy Antlia 2
Erkal, Denis; Belokurov, Vasily; Li, Ting S. +3 more
We report 350 pulsating variable stars found in four DECam fields (~12 deg2) covering the Antlia 2 satellite galaxy. The sample of variables includes 318 RR Lyrae stars and eight anomalous Cepheids in the galaxy. Reclassification of several objects designated previously to be RR Lyrae as anomalous Cepheids get rid of the satellite's sta…
Pearls on a String: Numerous Stellar Clusters Strung Along the Same Orbit
Rix, Hans-Walter; Fürnkranz, Verena; Coronado, Johanna
Stars originate from the dense interstellar medium, which exhibits filamentary structure to scales of ~1 kpc in galaxies like our Milky Way. We explore quantitatively how much resulting large-scale correlation there is among different stellar clusters and associations in orbit-phase space, characterized here by actions and angles. As a starting po…
Galactic Cosmic-Ray Propagation in the Inner Heliosphere: Improved Force-field Model
Peter, Annika H. G.; Beacom, John F.; Li, Jung-Tsung
A key goal of heliophysics is to understand how cosmic rays propagate in the solar system's complex, dynamic environment. One observable is solar modulation, i.e., how the flux and spectrum of cosmic rays change as they propagate inward. We construct an improved force-field model, taking advantage of new measurements of magnetic power spectral den…
Escape from the Bermuda cluster: Orphanization by multiple stellar ejections
Weiler, M.; Maíz Apellániz, J.; Barbá, R. H. +1 more
Context. Dynamical interactions in young stellar clusters can eject massive stars early in their lives and significantly alter their mass functions. If all of the most massive stars are lost, we are left with an orphan cluster.
Aims: We study the Bermuda cluster (Villafranca O-014 NW), the most significant young stellar group in the North Ame…
The Ultramassive White Dwarfs of the Alpha Persei Cluster
Caiazzo, Ilaria; Richer, Harvey B.; Heyl, Jeremy +2 more
We searched through the entire Gaia EDR3 candidate white dwarf catalog for stars with proper motions and positions that are consistent with them having escaped from the Alpha Persei cluster within the past 81 Myr, the age of the cluster. In this search we found five candidate white dwarf escapees from Alpha Persei and obtained spectra for all of t…
Chemical evolution of 26Al and 60Fe in the Milky Way
Matteucci, F.; Spitoni, E.; Vasini, A.
We present theoretical mass estimates of 26Al and 60Fe throughout the Galaxy, performed with a numerical chemical evolution model including detailed nucleosynthesis prescriptions for stable and radioactive nuclides. We compared the results for several sets of stellar yields taken from the literature, for massive, low and inte…
Visual binary stars with known orbits in Gaia EDR3
Malkov, Oleg; Chulkov, Dmitry
A total of 3350 objects from the Sixth Catalog of Orbits of Visual Binary Stars (ORB6) are investigated to validate Gaia Early Data Release 3 (EDR3) parallaxes and provide mass estimates for the systems. We show that two-thirds of binaries with a separation of 0.2-0.5 arcsec are left without a parallax solution in EDR3. Special attention is paid t…
Interstellar Neutral He Parameters from Crossing Parameter Tubes with the Interstellar Mapping and Acceleration Probe Informed by 10 yr of Interstellar Boundary Explorer Observations
McComas, D. J.; Fuselier, S. A.; Möbius, E. +11 more
The Sun's motion through the interstellar medium leads to an interstellar neutral (ISN) wind through the heliosphere. Several ISN species, including He, moderately depleted by ionization are observed with pickup ions and directly imaged. Since 2009, analyzed Interstellar Boundary Explorer (IBEX) observations returned a precise 4D parameter tube as…