Search Publications
An AO-assisted Variability Study of Four Globular Clusters
Contreras Ramos, R.; Catelan, M.; Hakala, P. +4 more
The image-subtraction technique applied to study variable stars in globular clusters represented a leap in the number of new detections, with the drawback that many of these new light curves could not be transformed to magnitudes due to severe crowding. In this paper, we present observations of four Galactic globular clusters, M 2 (NGC 7089), M 10…
The Short Rotation Period of Hi’iaka, Haumea’s Largest Satellite
Margot, Jean-Luc; Brown, Michael E.; Fabrycky, Daniel C. +5 more
Hi’iaka is the larger outer satellite of the dwarf planet Haumea. Using relative photometry from the Hubble Space Telescope and Magellan and a phase dispersion minimization analysis, we have identified the rotation period of Hi’iaka to be ∼9.8 hr (double peaked). This is ∼120 times faster than its orbital period, creating new questions about the f…
Star-forming Activity in the H II Regions Associated with the IRAS 17160-3707 Complex
Ojha, D. K.; Vig, S.; Ghosh, S. K. +3 more
We present a multiwavelength investigation of star formation activity toward the southern H II regions associated with IRAS 17160-3707, located at a distance of 6.2 kpc with a bolometric luminosity of 8.3 × 105 L ⊙. The ionized gas distribution and dust clumps in the parental molecular cloud are examined in detail using measu…
AKARI/IRC Near-infrared Spectral Atlas of Galactic Planetary Nebulae
Onaka, Takashi; Matsuura, Mikako; Sakon, Itsuki +2 more
Near-infrared (2.5-5.0 µm) low-resolution (λ/Δλ ∼ 100) spectra of 72 Galactic planetary nebulae (PNe) were obtained with the Infrared Camera (IRC) in the post-helium phase. The IRC, equipped with a 1‧ × 1‧ window for spectroscopy of a point source, was capable of obtaining near-infrared spectra in a slit-less mode without any flux loss due t…
Hubble Space Telescope Snapshot Survey for Resolved Companions of Galactic Cepheids
Schaefer, Gail H.; Bond, Howard E.; Evans, Nancy Remage +4 more
We have conducted an imaging survey with the Hubble Space Telescope Wide Field Camera 3 (WFC3) of 70 Galactic Cepheids, typically within 1 kpc, with the aim of finding resolved physical companions. The WFC3 field typically covers the 0.1 pc area where companions are expected. In this paper, we identify 39 Cepheids having candidate companions, base…
The SpaceInn-SISMA Database: Characterization of a Large Sample of Variable and Active Stars by Means of Harps Spectra
Roth, M.; Poretti, E.; Michel, E. +6 more
We created a large database of physical parameters and variability indicators by fully reducing and analyzing the large number of spectra taken to complement the asteroseismic observations of the COnvection, ROtation and planetary Transits (CoRoT) satellite. 7103 spectra of 261 stars obtained with the ESO echelle spectrograph HARPS have been store…
IVS Observation of ICRF2-Gaia Transfer Sources
Charlot, P.; Bourda, G.; Le Bail, K. +11 more
The second realization of the International Celestial Reference Frame (ICRF2), which is the current fundamental celestial reference frame adopted by the International Astronomical Union, is based on Very Long Baseline Interferometry (VLBI) data at radio frequencies in X band and S band. The European Space Agency’s Gaia mission, launched on 2013 De…
Very Low-mass Stellar and Substellar Companions to Solar-like Stars from MARVELS. VI. A Giant Planet and a Brown Dwarf Candidate in a Close Binary System HD 87646
Bizyaev, Dmitry; Ge, Jian; Schneider, Donald P. +34 more
We report the detections of a giant planet (MARVELS-7b) and a brown dwarf (BD) candidate (MARVELS-7c) around the primary star in the close binary system, HD 87646. To the best of our knowledge, it is the first close binary system with more than one substellar circumprimary companion that has been discovered. The detection of this giant planet was …
Resolved Companions of Cepheids: Testing the Candidates with X-Ray Observations
Schaefer, Gail H.; Bond, Howard E.; Evans, Nancy Remage +7 more
We have made XMM-Newton observations of 14 Galactic Cepheids that have candidate resolved (≥5″) companion stars based on our earlier HST Wide Field Camera 3 (WFC3) imaging survey. Main-sequence stars that are young enough to be physical companions of Cepheids are expected to be strong X-ray producers in contrast to field stars. XMM-Newton exposure…
Spectroscopic Orbits for 15 Late-type Stars
Abt, Helmut A.; Fekel, Francis C.; Willmarth, Daryl W. +1 more
Spectroscopic orbital elements are determined for 15 stars with periods from 8 to 6528 days with six orbits computed for the first time. Improved astrometric orbits are computed for two stars and one new orbit is derived. Visual orbits were previously determined for four stars, four stars are members of multiple systems, and five stars have Hippar…