相关论文: WISE J064336.71-022315.4: A Thick Disk L8 Gaia DR2…

We report a spectroscopic search for hypervelocity white dwarfs (WDs) that are runaways from Type Ia supernovae (SNe Ia) and related thermonuclear explosions. Candidates are selected from Gaia data with high tangential velocities and blue…

We use Kepler K2 Campaign 4 short-cadence (one-minute) photometry to measure white light flares in the young, moving group brown dwarfs 2MASS J03350208+2342356 (2M0335+23) and 2MASS J03552337+1133437 (2M0355+11), and report on long-cadence…

Previous analyses of various standard candles observed by the Gaia satellite have reported statistically significant systematics in the parallaxes that have improved from $\sim$250 $\mu$as in the first data release (DR1) to 50--80 $\mu$as…

We investigate the nature of nearby (10-15 kpc) high-speed stars in the Gaia DR2 archive identified on the basis of parallax, proper motion and radial velocity. Together with a consideration of their kinematic, orbital, and photometric…

We report the discovery of three nearby old halo white dwarf candidates in the Sloan Digital Sky Survey (SDSS), including two stars in a common proper motion binary system. These candidates are selected from our 2800 square degree proper…

We have measured a trigonometric parallax to the young brown dwarf 2MASSW J1207334-393254. The distance [54.0 (+3.2,-2.8) pc] and space motion confirm membership in the TW Hydrae Association. The primary is a ~25 M_jup brown dwarf. We…

The Wide-field Infrared Survey Explorer (WISE) is a powerful tool for finding nearby brown dwarfs and searching for new planets in the outer solar system, especially with the incorporation of NEOWISE and NEOWISE-Reactivation data. So far,…

The early third data release (EDR3) of the European Space Agency satellite Gaia provides coordinates, parallaxes, and proper motions for ~1.47 billion sources in our Milky Way, based on 34 months of observations. The combination of Gaia DR2…

WISE J104915.57-531906.1 A+B and WISE J085510.83-071442.5 were recently discovered as the third and fourth closest known systems to the Sun, respectively (2.0 and 2.3 pc). The former consists of a L8+T0.5 binary and the latter is a probable…

We present the discoveries of WISEA J041451.67-585456.7 and WISEA J181006.18-101000.5, two low-temperature (1200$-$1400 K), high proper motion T-type subdwarfs. Both objects were discovered via their high proper motion ($>$0.5 arcsec…

We successfully measured the trigonometric parallax of Sagittarius A* (Sgr A*) to be $117\pm17$ micro-arcseconds ($\mu$as) using the VLBI Exploration of Radio Astrometry (VERA) with the newly developed broad-band signal-processing system…

The recently discovered brown dwarf WISE 0855 presents our first opportunity to directly study an object outside the Solar System that is nearly as cold as our own gas giant planets. However the traditional methodology for characterizing…

Extrasolar planet searches targeting very low-mass stars and brown dwarfs are hampered by intrinsic or instrumental limitations. Time series of astrometric measurements with precisions better than one milli-arcsecond can yield new evidence…

We report the parallax and proper motion of five L dwarfs obtained with observations from the robotic Liverpool Telescope. Our derived proper motions are consistent with published values and have considerably smaller errors. Based on our…

We report the discovery of a new directly-imaged brown dwarf companion with Keck/NIRC2+pyWFS around a nearby mid-type M~dwarf LSPM~J1446+4633 (hereafter J1446). The $L'$-band contrast ($4.5\times10^{-3}$) is consistent with a $\sim20-60\…

We present parallax and proper motion measurements, near-infrared spectra, and WISE photometry for the low surface gravity L5gamma dwarf 2MASSJ035523.37+113343.7 (2M0355). We use these data to evaluate photometric, spectral, and kinematic…

We report resolved near-infrared spectroscopy and photometry of the recently identified brown dwarf binary WISE J104915.57-531906.1AB, located 2.02+/-0.15 pc from the Sun. Low-resolution spectral data from Magellan/FIRE and IRTF/SpeX reveal…

UCAC2 46706450 is a late-type star with an ultraviolet (UV) excess. It was considered a candidate to establish a sample of FGK stars with white dwarf (WD) companions that can be used to test binary evolution models. To verify the WD nature…

A selection of 17 stars in the Sloan Digital Sky Survey, previously identified as DC class white dwarfs (WDs), has been reported to show spectra very close to blackbody radiation in the wavelength range from ultraviolet to infrared. Due to…

The third data release (DR3) of the European Space Agency satellite Gaia provides coordinates, parallaxes, proper motions, and radial velocities for a sample of $\sim 34$ million stars. We use the combined 6-dimensional phase space…