Search Publications
Primary Velocity and Orbital Phase Effects on Planetary Detectability from Small Epoch Number Data Sets
Benneke, Björn; Blake, Geoffrey A.; Pelletier, Stefan +2 more
Cross-correlation analyses of high-resolution spectroscopic data have recently shown great success in directly detecting planetary signals and enabling the characterization of their atmospheres. One such technique aims to observe a system at multiple epochs and combine the measured planetary radial velocities from each epoch into a measurement of …
Orbital Parameters and Binary Properties of 37 FGK Stars in the Cores of Open Clusters NGC 2516 and NGC 2422
Mateo, Mario; Bailey, John I., III; Roederer, Ian U. +4 more
We present orbits for 24 binaries in the field of open cluster NGC 2516 (~150 Myr) and 13 binaries in the field of open cluster NGC 2422 (~130 Myr) using results from a multiyear radial-velocity (RV) survey of the cluster cores. Six of these systems are double-lined spectroscopic binaries. We fit these RV variable systems with orvara, a MCMC-based…
Speckle Interferometry at the OAN-SPM México: Multiband Astrometry of Double Stars Measured in 2018 and 2019
Guerrero, C. A.; Fernandes, M. Borges; Reyes-Ruiz, M. +9 more
In this paper we present multiband speckle interferometric measurements of double stars performed at the 2.1 m telescope of the Observatorio Astronómico Nacional, San Pedro Mártir, México. We focused our efforts on objects from the Washington Double Star Catalog that were observed during five runs allocated in 2018 and 2019. We report here 2101 as…
The Stellar Content of H72.97-69.39, a Potential Super Star Cluster in the Making
Hirschauer, Alec S.; Meixner, Margaret; Zinnecker, Hans +2 more
Young massive clusters and super star clusters (SSCs) represent an extreme mode of star formation. Far-infrared imaging of the Magellanic Clouds has identified one potential embedded SSC, HSO BMHERICC J72.971176-69.391112 (H72.97-69.39 in short), in the southwest outskirts of the Large Magellanic Cloud. We present Gemini Flamingos 2 and GSAOI near…
Speckle Interferometry at the U.S. Naval Observatory. XXIV
Matson, Rachel A.; Williams, Stephen J.; Mason, Brian D. +5 more
The results of 3611 intensified CCD observations of double stars, made with the 26 inch refractor of the U.S. Naval Observatory, are presented. Each observation of a system represents a combination of over 2000 short-exposure images. These observations are averaged into 1857 mean relative positions and range in separation from 0"341 to 128"644, wi…
Spatial Distribution of Ultraviolet Emission from Cometary Activity at 67P/Churyumov-Gerasimenko
Parker, Joel Wm.; Bertaux, Jean-Loup; Weaver, Harold A. +16 more
The Alice ultraviolet spectrograph on board the Rosetta orbiter provided the first near-nucleus ultraviolet observations of a cometary coma from arrival at comet 67P/Churyumov-Gerasimenko in 2014 August through 2016 September. The characterization of atomic and molecular emissions in the coma revealed the unexpected contribution of dissociative el…
Observations of the Bright Star in the Globular Cluster 47 Tucanae (NGC 104)
Benjamin, R. A.; Dupree, A.; Miller Bertolami, M. M. +3 more
The Bright Star in the globular cluster 47 Tucanae (NGC 104) is a post-asymptotic giant branch (post-AGB) star of spectral type B8 III. The ultraviolet spectra of late-B stars exhibit myriad absorption features, many due to species unobservable from the ground. The Bright Star thus represents a unique window into the chemistry of 47 Tuc. We have a…
Runaway Stars as Possible Sources of the Elliptical Ring Structures in NGC 7538
Fenske, Josephine; Arakawa, Jason; Fallscheer, Cassandra +1 more
Two large, ∼500 M⊙ elliptical ring structures have been identified in the high-mass star-forming region NGC 7538. The origin of these ring structures is unknown, so we investigate the possibility that a runaway O- or B-type star may have originated in or passed through the region and created either or both of the ring structures via ste…
The Circumstellar Gas of Phi Leonis in the UV
Eiroa, C.; Brown, Alexander; Grady, C. A. +2 more
HST UV spectra were obtained to study whether the φ Leo system has one or more stellar companions, as shown for the A-star dwarf, HR10, stellar pulsation, or transiting exocomets. During five partial HST observation sets spread over 13 months, redshifted gas with radial velocities up to +245 km s-1 was observed on one occasion, with low…
CCD Measurements of Double Stars at ASV and NAO Rozhen in 2019 and 2020
Cvetković, Zorica; Pavlović, Rade; Boeva, Svetlana
We continued our series of CCD observations of double and multiple stars during 2019 and 2020. A total of 331 pairs were observed at two stations, Serbian Astronomical Station on the mountain of Vidojevica (ASV) and Bulgarian National Astronomical Observatory at Rozhen (NAOR). They were performed using two telescopes, 1.4 m at ASV, and 2 m at NAOR…