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The Putative Old, Nearby Cluster Lodén 1 Does Not Exist
Wright, Jason T.; Curtis, Jason L.; Han, Eunkyu
Astronomers have access to precious few nearby, middle-aged benchmark star clusters. Within 500 pc, there are only NGC 752 and Ruprecht 147 (R147) at 1.5 and 3 Gyr, respectively. The Database for Galactic Open Clusters (WEBDA) also lists Lodén 1 as a 2 Gyr cluster at a distance of 360 pc. If this is true, Lodén 1 could become a useful benchmark cl…
Cool Subdwarf Investigations. III. Dynamical Masses of Low-metallicity Subdwarfs
Nelan, Edmund P.; Henry, Todd J.; Wasserman, Lawrence H. +2 more
We report dynamical mass measurements for the components of the previously known double-lined spectroscopic subdwarfs G 006-026 B and C using the Fine Guidance Sensors on the Hubble Space Telescope. To build the empirical mass-luminosity relation for low-metallicity subdwarfs, we collect four other subdwarf systems with dynamical masses that we co…
Radio Properties of Young Stellar Objects in the Core of the Serpens South Infrared Dark Cloud
Gutermuth, Robert A.; Tobin, John J.; Kern, Nicholas S. +2 more
We present deep radio continuum observations of the star-forming core of the Serpens South Infrared Dark Cloud with the Karl G. Jansky Very Large Array. Observations were conducted in two bands centered at 7.25 GHz (4.14 cm) and 4.75 GHz (6.31 cm) with a {σ }{rms} of 8.5 and 11.1 µJy/beam, respectively. We also use 2MASS, Spitzer …
Orbits of 12 Southern Binaries Based on Soar Speckle Observations
Docobo, J. A.; Mendez, R. A.; Campo, P. P. +1 more
New data obtained with the 4.1 m Southern Astrophysical Research (SOAR) telescope at Cerro Pachón, Chile, allowed us to revise the orbits and system masses of the following southern visual double stars: WDS 01477-4358 (I 52), WDS 01500-0408 (A 2602), WDS 02514-2139 (DON 43), WDS 03189-0101 (BU 1177), WDS 04142-4608 (RST 2338), WDS 06274-2544 (B 11…
Rotational Dynamics and Star Formation in the Nearby Dwarf Galaxy NGC 5238
Cannon, John M.; Teich, Yaron G.; McNichols, Andrew T. +10 more
We present new H I spectral-line images of the nearby low-mass galaxy NGC 5238, acquired with the Karl G. Jansky Very Large Array. Located at a distance of 4.51 ± 0.04 Mpc, NGC 5238 is an actively star-forming galaxy with widespread Hα and ultraviolet (UV) continuum emission. The source is included in many ongoing and recent nearby galaxy surveys,…
The Time-evolution of HH 2 from Four Epochs of HST Images
Velázquez, P. F.; Bally, J.; Raga, A. C. +2 more
We have analyzed four epochs of Hα and [S II] Hubble Space Telescope images of the HH 1/2 outflow (covering a time interval from 1994 to 2014) to determine proper motions and emission line fluxes of the knots of HH 2. We find that our new proper motions agree surprisingly well with the motions measured by Herbig & Jones, although there is part…
Orbits for Nine Binaries and One Linear Solution
Cvetković, Z.; Pavlović, R.; Ninković, S.
The subject of the present paper is the analysis of the orbital elements for nine binaries: WDS 00463-0634 = HDS 101, WDS 03264+3520 = HDS 430, WDS 03307-1926 = HDS 441, WDS 04025+0638 = HDS 510, WDS 09252+4606 = HDS 1353, WDS 09446+6459 = CHR 176, WDS 10294+1211 = HDS 1507, WDS 10596+1800 = HDS 1568, and WDS 14562+1745 = HDS 2108. The orbital ele…
A Deep Search for Additional Satellites around the Dwarf Planet Haumea
Brown, Michael E.; Ragozzine, Darin; Burkhart, Luke D.
Haumea is a dwarf planet with two known satellites, an unusually high spin rate, and a large collisional family, making it one of the most interesting objects in the outer solar system. A fully self-consistent formation scenario responsible for the satellite and family formation is still elusive, but some processes predict the initial formation of…
Lunar Occultations of 18 Stellar Sources from the 2.4 m Thai National Telescope
Dhillon, V. S.; Marsh, T. R.; Richichi, A. +3 more
We report further results from the program of lunar occultation (LO) observations started at the 2.4 m Thai National Telescope (TNT) in 2014. We have recorded LO events of 18 stellar sources, leading to the detection of four angular diameters and two binary stars. With two exceptions, these are first-time determinations. We could resolve angular d…
Hubble Space Telescope Observations of Active Asteroid 324P/La Sagra
Mutchler, Max; Jewitt, David; Agarwal, Jessica +3 more
Hubble Space Telescope observations of active asteroid 324P/La Sagra near perihelion show continued mass loss consistent with the sublimation of near-surface ice. Isophotes of the coma measured from a vantage point below the orbital plane are best matched by steady emission of particles having a nominal size of a ∼ 100 µm. The inferred rate …