Search Publications
A Lithium Depletion Age for the Carina Association
Kraus, Adam L.; Barber, Madyson G.; Mann, Andrew W. +6 more
The dispersed remnants of stellar nurseries, stellar associations, provide unparalleled samples of coeval stars critical for studies of stellar and planetary formation and evolution. The Carina Stellar Association is one of the closest stellar associations to Earth, and yet measurements of its age have varied from 13 to 45 Myr. We aim to update th…
Backscattering and Line Broadening in Orion
O'Dell, C. R.; Ferland, G. J.; Méndez-Delgado, J. E.
Examination of emission lines in high-velocity-resolution optical spectra of the Orion Nebula confirms that the velocity component on the red wing of the main ionization front emission line is due to backscattering in the Photon Dominated Region. This scattered light component has a weak wavelength dependence that is consistent with either general…
Evidence for the Disruption of a Planetary System During the Formation of the Helix Nebula
Kemper, Francisca; Villaver, Eva; Ertel, Steve +5 more
The persistence of planetary systems after their host stars evolve into their post-main-sequence phase is poorly constrained by observations. Many young white dwarf systems exhibit infrared excess emission and/or spectral absorption lines associated with a reservoir of dust (or planetesimals) and its accretion. However, most white dwarfs are too c…
Faint but Not Forgotten. I. First Results from a Search for Astrospheres around AGB Stars in the Far-ultraviolet
Sahai, Raghvendra; Stenger, Benjamin
Using the GALEX archive, we have discovered extended structures around ten asymptotic giant branch (AGB) stars (out of a total 92 searched) emitting in the far-ultraviolet (FUV) band. In all but one, we find the typical morphology expected for a spherical wind moving relative to, and interacting with, the interstellar medium (ISM) to produce an as…
The Emergence of a Neutral Wind Region in the Orbital Plane of Symbiotic Binaries during Their Outbursts
Skopal, Augustin
Accretion of mass onto a white dwarf (WD) in a binary system can lead to stellar explosions. If a WD accretes from stellar wind of a distant evolved giant in a symbiotic binary, it can undergo occasional outbursts in which it brightens by several magnitudes, produces a low- and high-velocity mass outflow, and, in some cases, ejects bipolar jets. I…
Clustering Properties of Intermediate and High-mass Young Stellar Objects
Ribas, Álvaro; Kuhn, Michael A.; Oudmaijer, René D. +6 more
We have selected 337 intermediate- and high-mass young stellar objects (YSOs; 1.5-20 M ⊙) well-characterized with spectroscopy. By means of the clustering algorithm HDBSCAN, we study their clustering and association properties in the Gaia DR3 catalog as a function of stellar mass. We find that the lower-mass YSOs (1.5-4 M ⊙) …
The Cassiopeia Filament: A Blown Spur of the Local Arm
Fang, Min; Chen, Zhiwei; Zhang, Shiyu +12 more
We present wide-field and high-sensitivity CO(1-0) molecular line observations toward the Cassiopeia region, using the 13.7 m millimeter telescope of the Purple Mountain Observatory. The CO observations reveal a large-scale highly filamentary molecular cloud within the Galactic region of 132.°0 ≥ l ≥ 122.°0 and -1.°0 ≤ b ≤ 3.°0 and the velocity ra…
The 14 Her Planetary System: Companion Masses and Architecture from Radial Velocities and Astrometry
McArthur, B. E.; Benedict, G. F.; Nelan, E. P. +1 more
We combine Hubble Space Telescope (HST) Fine Guidance Sensor, Hipparcos, and Gaia DR3 astrometric observations of the K0 V star 14 Her with the results of an analysis of extensive ground-based radial velocity data to determine perturbation orbits and masses for two previously known companions, 14 Her b and c. Radial velocities obtained with the Ho…
OGLE-2019-BLG-0825: Constraints on the Source System and Effect on Binary-lens Parameters Arising from a Five-day Xallarap Effect in a Candidate Planetary Microlensing Event
Peixinho, Nuno; Han, Cheongho; Udalski, Andrzej +90 more
We present an analysis of microlensing event OGLE-2019-BLG-0825. This event was identified as a planetary candidate by preliminary modeling. We find that significant residuals from the best-fit static binary-lens model exist and a xallarap effect can fit the residuals very well and significantly improves χ 2 values. On the other hand, b…
The Mass-Temperature Relation for B and Early A Stars Based on International Ultraviolet Explorer Spectra of Detached Eclipsing Binaries
Torres, Guillermo; Evans, Nancy Remage; Kuraszkiewicz, Joanna +4 more
Ultraviolet spectra were taken of 25 detached eclipsing binaries (DEBs) with spectral types O, B, and early A with the International Ultraviolet Explorer satellite in the 1150-1900 Å region. The spectra were compared with BOSZ model atmospheres. The composite spectra of the DEBs were modeled by a combination of models representing the hot and cool…