相关论文: Identification of red high proper-motion objects i…

In this paper, we describe how to use the Maximum Reduced Proper Motion method (Phan-Bao et al. 2003) to detect 57 nearby L and late-M dwarfs (d_phot <= 30 pc): 36 of them are newly discovered. Spectroscopic observations of 43 of the 57…

Benchmark brown dwarfs are those objects for which fiducial constraints are available, including effective temperature, parallax, age, metallicity. We searched for new cool brown dwarfs in 186 sq.deg. of the new area covered by the data…

We report new spectroscopic results, obtained with UKIRT/CGS4, of a sample of 14 candidate ultracool dwarfs selected from the DENIS (Deep Near-Infrared Survey of the Southern Sky) database. A further object, selected from the 2MASS Second…

Surveys for nearby low-luminosity dwarfs tend to avoid the crowded regions of the Galactic Plane. We have devised near-infrared colour-magnitude and colour-colour selection criteria designed to identify late-type M and early-type L dwarfs…

In this work, we present new catalogs of M giant and M dwarf stars from the LAMOST DR5. In total, 39,796 M giants and 501,152 M dwarfs are identified from the classification pipeline. The template-fitting results contain M giants with 7…

We present the discovery and spectroscopic identification of two very high proper motion ancient white dwarf stars, found in a systematic proper motion survey. Their kinematics and apparent magnitude clearly indicate that they are halo…

We present the completion of a program to cross-correlate the SDSS Data Release 1 and 2MASS Point Source Catalog in search for extremely red L and T dwarfs. The program was initiated by Metchev and collaborators, who presented the findings…

We have conducted a search for new stars of high proper motion ($\geq$0.4 arcsec yr$^{-1}$) using POSS II fields for which an extra IIIaF (red) plate of good quality exists, along with useable IIIaJ (blue) and IV-N (infrared) plates taken…

We have created a framework to facilitate the construction of specialized target lists for radial velocity surveys that are biased toward stars that (1) possess planets and (2) are easiest to observe with current detection techniques. We…

Young brown dwarfs share many properties with directly imaged giant extrasolar planets. They therefore provide unique laboratories for investigating the full range of temperature and mass encompasses by the growing collection of planets…

Context. Being the most numerous and oldest stars in the galaxy, M dwarfs are objects of great interest for exoplanet searches. The presence of molecules in their atmosphere complicates our understanding of their atmospheric properties. But…

(abridged) Deep multi-epoch Sloan Digital Sky Survey data in a 275 square degrees area along the celestial equator (SDSS stripe 82 = S82) allowed us to search for extremely faint ($i>21$) objects with proper motions larger than 0.14…

We present an analysis of long-term photometric variability for nearby red dwarfs at optical wavelengths. The sample consists of 264 M dwarfs south of DEC = +30 with V-K = 3.96-9.16 and Mv~10-20 (spectral types M2V-M8V), most of which are…

The stellar composition of the Tycho-2 Catalogue in the range $0.75<B-V<1.25$ has been reproduced through Monte Carlo simulations. For young and old stars of the red giant clump (RGC), the red giant branch, subgiants, red dwarfs, and…

We define an enhanced spectral classification scheme for M dwarf stars, and use it to derive spectral classification of 104 northern stars with proper motions larger than 0.5"/yr which we discovered in a survey of high proper motion stars…

We identify proper motion objects in the Hubble Ultra Deep Field (UDF) using the optical data from the original UDF program in 2004 and the near-infrared data from the 128-orbit UDF 2012 campaign. There are 12 sources brighter than I=27 mag…

AIMS: We checked a sample of 545 F stars within 50 pc for wide companions using existing near-infrared and optical sky surveys. METHODS: Applying the common proper motion (CPM) criterion, we detected wide companion candidates with 6-120…

We estimate effective temperature ($T_{\rm eff}$), stellar radius, and luminosity for a sample of 271 M-dwarf stars (M0V-M7V) observed as a part of CARMENES (Calar Alto high-Resolution search for M dwarfs with Exo-earths with Near-infrared…

A search of the Sloan Digital Sky Survey spectroscopic database has turned up 23 new ultra-cool subdwarfs, low-mass metal-poor stars of spectral subtype M 7.0 or later. Spectra from these red objects all show very strong molecular bands of…

The Red MSX Source (RMS) survey is a multi-wavelength programme of follow-up observations designed to distinguish between genuine massive young stellar objects (MYSOs) and other embedded or dusty objects, such as ultra compact (UC) HII…