819 datasets found

We studied a sample of 415 associated (z_abs_~z_em_; relative velocity with respect to QSO in units of c, {beta}<0.01) MgII absorption systems with 1.0<=z_abs_<=1.86,...

Recent work has suggested that the fraction of obscured AGNs declines with increasing luminosity, but it has been difficult to quantify this trend. Here we attempt to measure...

We report new L and T dwarfs found in a cross-match of the SDSS Data Release 1 and 2MASS. Our simultaneous search of the two databases effectively allows us to relax the...

We use a simple optical/infrared (IR) photometric selection of high-redshift QSOs that identifies a Lyman break in the optical photometry and requires a red IR color to...

We derive masses and radii for both components in the single-lined eclipsing binary HAT-TR-205-013, which consists of an F7 V primary and a late M dwarf secondary. The system's...

We study quasar clustering on small scales, modeling clustering amplitudes using halo-driven dark matter descriptions. From 91 pairs n scales <35h^-1^kpc, we detect only a...

SDF (Subaru Deep Field) line-emitting galaxies in four narrow-band filters at low and intermediate redshifts are presented. Broadband colors, follow-up optical spectroscopy, and...

We present the clustering of Deep Extragalactic Evolutionary Probe 2 (DEEP2) galaxies at 0.7<z<1.4 around quasars identified using both the Sloan Digital Sky Survey (SDSS)...

With close pairs of quasars at different redshifts, a background quasar sight line can be used to study a foreground quasar's environment in absorption. We search 149...

SDSS repeat spectroscopic observations have resulted in multiepoch spectroscopy for 2500 quasars observed more than 50 days apart. From this sample, calibrating against stars...

We present the full spectroscopic white dwarf and hot subdwarf sample from the Sloan Digital Sky Survey (SDSS) First Data Release, DR1. We find 2551 white dwarf stars of various...

We search for nearby, isolated, accreting, "stellar-mass" (3-100M_{sun}_) black holes. Models suggest a synchrotron spectrum in visible wavelengths and some emission in X-ray...

Transmission spectroscopy offers an invaluable opportunity to characterize the atmospheres of exoplanets. We present new ground-based optical transmission spectra of the hot...

We obtained high-resolution spectra of the ultracool M-dwarf TRAPPIST-1 during the transit of its planet "b" using two high-dispersion near-infrared spectrographs, the Infrared...

Photometric observations of 12 totally eclipsing W UMa binaries (NSVS 3325547, V646 Lac, V1320 Cas, V539 Dra, V816 Cep, NSVS 9045055, V1115 Cas, V902 Cep, V596 Peg, NSVS...

M subdwarfs are low-metallicity M dwarfs that typically inhabit the halo population of the Galaxy. Metallicity controls the opacity of stellar atmospheres; in metal-poor stars,...

A large extension of the Sextans dwarf spheroidal galaxy, 7 deg^2^, has been surveyed for variable stars using the Dark Energy Camera at the Blanco Telescope at Cerro Tololo...

We present a sample of 74216 M and L dwarfs constructed from two existing catalogs of cool dwarfs spectroscopically identified in the Sloan Digital Sky Survey (SDSS). We...

The Asteroid Terrestrial-impact Last Alert System (ATLAS) carries out its primary planetary defense mission by surveying about 13000 deg^2^ at least four times per night. The...

We report observations of the known cataclysmic variable star (CV) V704 And, and also confirm that the optical counterpart of the ROSAT Galactic Plane Survey source RX J2338+431...