Search Publications
The Closest M-dwarf Quadruple System to the Sun
White, R. J.; Quinn, S. N.; Riedel, A. R. +8 more
We report new infrared radial velocity measurements obtained with CSHELL at NASA's Infrared Telescope Facility that reveal the M3.5 dwarf GJ 867B to be a single-lined spectroscopic binary with a period of 1.795 ± 0.017 days. Its velocity semi-amplitude of 21.4 ± 0.5 km s-1 corresponds to a minimum mass of 61 ± 7 M JUP; the ne…
A Detailed Study of the Structure of the Nested Planetary Nebula, Hb 12, the Matryoshka Nebula
Winge, C.; López, J. A.; Edwards, M. L. +1 more
We present near-IR, integral field spectroscopic observations of the planetary nebula (PN) Hb 12 using Near-infrared Integral Field Spectrograph (NIFS) on Gemini-North. Combining NIFS with the adaptive optics system Altair, we provide a detailed study of the core and inner structure of this PN. We focus the analysis in the prominent emission lines…
Orbits for Eight Hipparcos Double Stars
Cvetković, Z.; Pavlović, R.; Ninković, S.
In this paper, we analyze new orbital elements and the quantities that follow from them for eight binaries: WDS 00101+3825 = HDS 23Da,Db, WDS 00321-1218 = HDS 71, WDS 04287+2613 = HDS 576, WDS 04389-1207 = HDS 599, WDS 16206+4535 = HDS 2309, WDS 17155+1052 = HDS 2440, WDS 22161-0705 = HDS 3158, and WDS 23167+3441 = HDS 3315. For seven of them, the…
Herschel Observations of Circinus X-1 during Outburst and Quiescence
Harrison, Thomas E.; Gelino, Dawn M.; Buxton, Michelle +1 more
We have used the Photodetector Array Camera and Spectrometer and Spectral and Photometric Imaging REceiver instruments on the Herschel Space Observatory to observe Cir X-1 both in and out of outburst. We detected Cir X-1 during outburst at 70 µm. Unfortunately, a cold background source dominates Cir X-1 at longer wavelengths. We have assembl…
The Period Analysis of V418 Aql, SU Boo, RV CVn, CR Cas, GV Cyg, V432 Per, and BD+42 2782
Wolf, M.; Kučáková, H.; Uhlař, R. +1 more
The minimum timings of eclipsing binaries V418 Aql, SU Boo, RV CVn, CR Cas, GV Cyg, V432 Per, and BD+42 2782 were collected and analyzed. Their long-term behavior was studied via period analysis, revealing a periodic term in eclipse times. We derived 576 new times of minimum. Hence, to describe the periodic variation, a third-body hypothesis was p…
The Three-body System δ Circini
Mayer, Pavel; Harmanec, Petr; Sana, Hugues +1 more
Delta Cir is known as an O7.5 III eclipsing and spectroscopic binary with an eccentric orbit. Penny et al. discovered the presence of a third component in the IUE spectra. The eclipsing binary and the third body revolve around a common center of gravity with a period of 1644 days in an eccentric orbit with a semimajor axis of 10 AU. We demonstrate…
Measuring Metallicities with Hubble Space Telescope/Wide-Field Camera 3 Photometry
Bond, Howard E.; Anthony-Twarog, Barbara J.; Holtzman, Jon A. +4 more
We quantified and calibrated the metallicity and temperature sensitivities of colors derived from nine Wide-Field Camera 3 filters on board the Hubble Space Telescope using Dartmouth isochrones and Kurucz atmosphere models. The theoretical isochrone colors were tested and calibrated against observations of five well studied galactic clusters, M92,…
A Magnified View of Star Formation at z = 0.9 From Two Lensed Galaxies
Veilleux, Sylvain; Rigby, Jane R.; Swinbank, Mark +1 more
We present new narrowband Hα imaging from the Hubble Space Telescope of two z = 0.91 galaxies that have been lensed by the foreground galaxy cluster A2390. These data probe spatial scales as small as ~0.3 kpc, providing a magnified look at the morphology of star formation at an epoch when the global star formation rate (SFR) was high. However, dus…
First Ultraviolet Reflectance Measurements of Several Kuiper Belt Objects, Kuiper Belt Object Satellites, and New Ultraviolet Measurements of a Centaur
Stern, S. A.; Schindhelm, R.; Cunningham, N. J.
We observed the 2600-3200 Å (hereafter, mid-UV) reflectance of two Kuiper Belt Objects (KBOs), two KBO satellites, and a Centaur, using the Hubble Space Telescope (HST) Cosmic Origins Spectrograph (COS). Other than measurements of the Pluto system, these constitute the first UV measurements obtained of KBOs, and KBO satellites, and new HST UV meas…
The Massive Star Population in M101. II. Spatial Variations in the Recent Star Formation History
Humphreys, Roberta M.; Grammer, Skyler
We investigate star formation history (SFH) as a function of radius in M101 using archival Hubble Space Telescope Advanced Camera for Surveys photometry. We derive the SFH from the resolved stellar populations in five 2' wide annuli. Binning the SFH into time frames corresponding to stellar populations traced by Hα, far-ultraviolet, and near-ultra…