299 citations · 1.1k across the 23 of their papers we have counts for
11 papers · 1 filter
The elderly among the oldest: new evidence for extremely metal-poor RR Lyrae stars
Valentina D'Orazi, Vittorio F. Braga, Giuseppe Bono +21
We performed a detailed spectroscopic analysis of three extremely metal-poor RR Lyrae stars, exploring uncharted territories at these low metallicities for this class of stars. Usi…
The SAGE-Spec Spitzer Legacy program: The life-cycle of dust and gas in the Large Magellanic Cloud. Point source classification III
Olivia C. Jones, Paul M. Woods, F. Kemper +16
The Infrared Spectrograph (IRS) on the {\em Spitzer Space Telescope} observed nearly 800 point sources in the Large Magellanic Cloud (LMC), taking over 1,000 spectra. 197 of these…
Spectral Evidence for an Inner Carbon-Rich Circumstellar Dust Belt in the Young HD36546 A-Star System
Carey M. Lisse, Mike L. Sitko, Ray W. Russell +5
Using the NASA/IRTF SpeX & BASS spectrometers we have obtained novel 0.7 - 13 um observations of the newly imaged HD36546 debris disk system. The SpeX spectrum is most consistent w…
On the distance of the globular cluster M4 (NGC 6121) using RR Lyrae stars: II. Mid-infrared period-luminosity relations
J. R. Neeley, M. Marengo, G. Bono +12
New mid-infrared period-luminosity (PL) relations are presented for \rrl{} variables in the globular cluster M4 (NGC 6121). Accurate photometry was obtained for 37 \rrl{} variables…
Optical and Near-Infrared UBVRIJHK Photometry for the RR Lyrae stars in the Nearby Globular Cluster M4 (NGC 6121)
P. B. Stetson, V. F. Braga, M. Dall'Ora +6
We present optical and near-infrared UBVRIJHK photometry of stars in the Galactic globular cluster M4 (NGC 6121) based upon a large corpus of observations obtained mainly from publ…
A Mid-Infrared Search for Substellar Companions of Nearby Planet-Host Stars
Alan Hulsebus, Massimo Marengo, Joe Carson +1
Determining the presence of widely separated substellar-mass companion is crucial to understand the dynamics of inner planets in extrasolar planetary systems (e.g. to explain their…
Spitzer observations of NGC2264: The nature of the disk population
P. S. Teixeira, C. J. Lada, M. Marengo +1
NGC2264 is a young cluster with a rich circumstellar disk population which makes it an ideal target for studying the evolution of stellar clusters. Our goal is to study its star fo…
Evidence for Pulsation-Driven Mass Loss from delta Cephei
M. Marengo, N. R. Evans, L. D. Matthews +7
We found the first direct evidence that the Cepheid class namesake, delta Cephei, is currently losing mass. These observations are based on data obtained with the Spitzer Space Tel…
New Evidence for Mass Loss from delta Cephei from HI 21-cm Line Observations
L. D. Matthews, M. Marengo, N. R. Evans +1
Recently published Spitzer observations of the classical Cepheid archetype delta Cephei revealed an extended dusty nebula surrounding this star and its hot companion. The infrared…
Synthetic Cepheid Period-Luminosity & Period-Color Relations in Spitzer's IRAC Bands
C. -C. Ngeow, M. Marconi, I. Musella +3
The mid-infrared period-luminosity (P-L) relation for Cepheids will be important in the JWST era, as it holds the promise of deriving the Hubble constant within 2% accuracy. We pre…
A Spitzer IRAC Imaging Survey for T Dwarf Companions Around M, L, and T Dwarfs: Observations, Results, and Monte Carlo Population Analyses
Joseph Carson, Massimo Marengo, Brian Patten +8
We report observational techniques, results, and Monte Carlo population analyses from a Spitzer Infrared Array Camera imaging survey for substellar companions to 117 nearby M, L, a…