586 datasets found

Theoretical studies suggest that C/O and Mg/Si are the most important elemental ratios in determining the mineralogy of terrestrial planets. The C/O ratio controls the...

We report the results of an infrared Doppler survey designed to detect brown dwarf and giant planetary companions to a magnitude-limited sample of ultracool dwarfs (UCDs). Using...

A search for young substellar objects in the {rho} Oph cloud core region has been made with the aid of multiband profile-fitting point-source photometry of the deep-integration...

We present new Spitzer Infrared Array Camera (IRAC) photometry of 12 very late-type T dwarfs: nine have [3.6], [4.5], [5.8], and [8.0] photometry and three have [3.6] and [4.5]...

We report the identification of 17 candidate brown dwarf binaries whose components straddle the L dwarf/T dwarf transition. These sources were culled from a large near-infrared...

We report on the structure of the nuclear star cluster in the innermost 0.16pc of the Galaxy as measured by the number density profile of late-type giants. Using laser guide...

We present the results of a five month photometric time-series survey for stellar rotation over a 40'x40' field centered on the 150Myr open cluster M35 (=NGC 2168). We report...

Deep ACS slitless grism observations and identification of stellar sources are presented within the Great Observatories Origins Deep Survey North and South fields which were...

Using a large sample of optical spectra of late-type dwarfs, we identify a subset of late-M through L field dwarfs that, because of the presence of low-gravity features in their...

Using the longest baselines of the CHARA Array, we have measured the angular diameter of the G5V subdwarf {mu} Cas A, the first such determination for a halo population star. We...

We present results from K-band slit scan observations of a ~20"x20" region of the Galactic center (GC) in two separate epochs more than 5 years apart. The high-resolution...

We use the Spitzer Space Telescope to search for infrared excess at 24, 70, and 160um due to debris disks around a sample of 45 FGK-type members of the Hyades. We supplement our...

We present the results of SiO millimeter line observations of a sample of known SiO maser sources covering a wide dust temperature range. A cold part of the sample was selected...

A sample of 119 F, G, and K solar neighborhood stars, selected under the condition [Fe/H]>0.00, is investigated in order to detect which of them, if any, present...

We present an analysis of 402 F, G, and K solar neighborhood stars, with accurate estimates of [Fe/H] in the range -1.0 to +0.5dex, aimed at the detection of {alpha}-enhanced...

We analyze the high-excitation O I {lambda}7774 triplet in high-resolution, moderate signal-to-noise ratio spectra of 15 Pleiades and eight M34 open cluster dwarfs over the...

Synthetic Lick indices computed with solar scaled abundances and with {alpha}-element enhancement are presented and compared with predictions from both theoretical computations...

We present {lambda}/{Delta}{lambda}=550-1200 near-infrared H and K spectra for a magnitude-limited sample of 79 asymptotic giant branch and cool supergiant stars in the central...

In the present study we analyze the behavior of the rotational velocity, vsini, for a large sample of 134 spectroscopic binary systems with a giant star component of luminosity...

We investigate the low-mass population of the young cluster IC 348 down to the deuterium-burning limit, a fiducial boundary between brown dwarf and planetary mass objects, using...