Search Publications
A Magellan MIKE and Spitzer MIPS Study of 1.5-1.0 M sun Stars in Scorpius-Centaurus
Weinberger, Alycia J.; Chen, Christine H.; Mamajek, Eric E. +3 more
We obtained Spitzer Space Telescope Multiband Imaging Photometer for Spitzer (MIPS) 24 µm and 70 µm observations of 182 nearby, Hipparcos F- and G-type common proper motion single and binary systems in the nearest OB association, Scorpius-Centaurus. We also obtained Magellan/MIKE R ~ 50,000 visual spectra at 3500-10500 Å for 181 candid…
The Pan-Pacific Planet Search. I. A Giant Planet Orbiting 7 CMa
Endl, Michael; Wittenmyer, Robert A.; Wang, Liang +3 more
We introduce the Pan-Pacific Planet Search, a survey of 170 metal-rich Southern Hemisphere subgiants using the 3.9 m Anglo-Australian Telescope. We report the first discovery from this program, a giant planet orbiting 7 CMa (HD 47205) with a period of 763 ± 17 days, eccentricity e = 0.14 ± 0.06, and msin i = 2.6 ± 0.6 M Jup. The host st…
The Edge of the Milky Way Stellar Disk Revealed Using Clump Giant Stars as Distance Indicators
Minniti, D.; Saito, R. K.; Alonso-García, J. +2 more
We use the clump giants of the disk as standard candles calibrated from Hipparcos parallaxes in order to map their distribution with two new near-infrared surveys of the Galactic plane: UKIDSS-GPS and VISTA Variables in the Vía Láctea (VVV). We explore different selection cuts of clump giants. We conclude that there is an edge of the stellar disk …
Optical Polarization Mapping Toward the Interface Between the Local Cavity and Loop I
Santos, Fábio P.; Corradi, Wagner; Reis, Wilson
The Sun is located inside an extremely low density and quite irregular volume of the interstellar medium, known as the Local Cavity (LC). It has been widely believed that some kind of interaction could be occurring between the LC and Loop I, a nearby superbubble seen in the direction of the Galactic center. As a result of such interaction, a wall …
PDR Model Mapping of Physical Conditions via Spitzer/IRS Spectroscopy of H2: Theoretical Success toward NGC 2023-South
Wolfire, M. G.; Sheffer, Y.; Hollenbach, D. J. +2 more
We use the Infrared Spectrograph on Spitzer to observe the southern part of the reflection nebula NGC 2023, including the Southern Ridge, which is a photodissociation region (PDR) par excellence excited by HD 37903. Five pure-rotational H2 emission lines are detected and mapped over and around the Southern Ridge in order to compare with…
Concerning the Classical Cepheid VI C Wesenheit Function's Strong Metallicity Dependence
Gieren, W.; Turner, D.; Majaess, D.
Evidence is presented which supports findings that the classical Cepheid VI C period Wesenheit function is relatively insensitive to metallicity. The viability of a recently advocated strong metallicity dependence was evaluated by applying the proposed correction (γ = -0.8 mag dex-1) to distances established for the Magella…
Chandra Evidence for Extended X-Ray Structure in RY Tau
Skinner, Stephen L.; Güdel, Manuel; Audard, Marc
We report results of a sensitive Chandra ACIS-S observation of the classical T Tauri star RY Tau. Previous studies have shown that it drives a spectacular bipolar jet whose blueshifted component is traced optically along P.A. ≈ 295° at separations of 1farcs5-31'' from the star. Complex X-ray emission is revealed, including a very soft non-variable…
Mid-infrared Period-luminosity Relations of RR Lyrae Stars Derived from the WISE Preliminary Data Release
Bloom, Joshua S.; Richards, Joseph W.; Butler, Nathaniel R. +1 more
Interstellar dust presents a significant challenge to extending parallax-determined distances of optically observed pulsational variables to larger volumes. Distance ladder work at mid-infrared wavebands, where dust effects are negligible and metallicity correlations are minimized, has been largely focused on few-epoch Cepheid studies. Here we pre…