Search Publications
White-light Observations of Solar Wind Transients and Comparison with Auxiliary Data Sets
DeForest, C. E.; Howard, T. A.; Reinard, A. A.
This paper presents results utilizing a new data processing pipeline for STEREO/SECCHI. The pipeline is used to identify and track 24 large- and small-scale solar wind transients from the Sun out to 1 AU. This comparison was performed during a few weeks around the minimum at the end of Solar Cycle 23 and the start of Cycle 24 (2008 December to 200…
Spitzer Observations of the HH 1/2 System: The Discovery of the Counterjet
Raga, A. C.; Noriega-Crespo, A.
We present unpublished Spitzer IRAC observations of the HH 1/2 young stellar outflow processed with a high angular resolution deconvolution algorithm that produces subarcsecond (~0farcs6-0farcs8) images. In the resulting mid-infrared images, the optically invisible counterjet is detected for the first time. The counterjet is approximately half as …
Discovery of Bright Galactic R Coronae Borealis and DY Persei Variables: Rare Gems Mined from ACVS
Cenko, S. B.; Bloom, J. S.; Stassun, K. G. +4 more
We present the results of a machine-learning (ML)-based search for new R Coronae Borealis (RCB) stars and DY Persei-like stars (DYPers) in the Galaxy using cataloged light curves from the All-Sky Automated Survey (ASAS) Catalog of Variable Stars (ACVS). RCB stars—a rare class of hydrogen-deficient carbon-rich supergiants—are of great interest owin…
AKARI Observation of the North Ecliptic Pole (NEP) Supercluster at z = 0.087: Mid-infrared View of Transition Galaxies
Kim, Seong Jin; Papovich, Casey; Weiner, Benjamin J. +12 more
We present the mid-infrared (MIR) properties of galaxies within a supercluster in the north ecliptic pole region at z ~ 0.087 observed with the AKARI satellite. We use data from the AKARI NEP-Wide (5.4 deg2) IR survey and the CLusters of galaxies EVoLution studies (CLEVL) mission program. We show that near-IR (3 µm)-mid-IR (11 &mi…
2M1155-79 (= T Chamaeleontis B): A Low-mass, Wide-separation Companion to the nearby, "Old" T Tauri Star T Chamaeleontis
Montez, Rodolfo; Murphy, Simon J.; Kastner, Joel H. +3 more
The early-K star T Cha, a member of the nearby (D ≈ 100 pc) epsilon Cha Association, is a relatively "old" (age ~ 7 Myr) T Tauri star that is still sporadically accreting from an orbiting disk whose inner regions are now evidently being cleared by a close, substellar companion. We report the identification, via analysis of proper motions, serendip…
Evidence for Fresh Frost Layer on the Bare Nucleus of Comet Hale-Bopp at 32 AU Distance
Pál, András; Sárneczky, Krisztián; Juhász, Attila +4 more
Here, we report that the activity of comet Hale-Bopp ceased between late 2007 and 2009 March, at about 28 AU distance from the Sun. At that time, the comet resided at a distance from the Sun that exceeded the freeze-out distance of regular comets by an order of magnitude. A Herschel Space Observatory PACS scan was taken in mid-2010, in the already…
Ultraviolet Measurements of Interstellar C2
Federman, S. R.; Sheffer, Y.; Hupe, Ryan C.
We analyzed archival spectra acquired with the Hubble Space Telescope for a study of interstellar C2. Absorption from the electronic transitions, D 1Σ+ u - X 1Σ+ g (0,0) as well as F 1Πu - X 1Σ+ g (0,0) and (1,0), was…
New Evidence Supporting Cluster Membership for the Keystone Calibrator Delta Cephei
Gieren, W.; Turner, D.; Majaess, D.
New and existing UBVJHKs , spectroscopic, NOMAD, Hubble Space Telescope, and revised Hipparcos observations are employed to determine properties for δ Cep and its host star cluster. The multi-faceted approach ensured that uncertainties were mitigated (σ/d ~ 2%). The following fundamental parameters were inferred for δ Cep: E(B - V) = 0.…
Model Selection for Spectropolarimetric Inversions
Orozco Suárez, D.; Asensio Ramos, A.; Martínez González, M. J. +3 more
Inferring magnetic and thermodynamic information from spectropolarimetric observations relies on the assumption of a parameterized model atmosphere whose parameters are tuned by comparison with observations. Often, the choice of the underlying atmospheric model is based on subjective reasons. In other cases, complex models are chosen based on obje…
The Kinematics of HH 34 from HST Images with a Nine-year Time Baseline
Stapelfeldt, K. R.; Raga, A. C.; Lora, V. +3 more
We study archival HST [S II] 6716+30 and Hα images of the HH 34 outflow, taken in 1998.71 and in 2007.83. The ~9 yr time baseline and the high angular resolution of these observations allow us to carry out a detailed proper-motion study. We determine the proper motions of the substructure of the HH 34S bow shock (from the [S II] and Hα frames) and…