相关论文: The first pre-supersoft X-ray binary

We present the first brown dwarf spectral binary characterized with JWST: WISE J014656.66+423410.0, the coldest blended-light brown dwarf binary straddling the T/Y transition. We obtained a moderate resolution (R$\sim$2700) G395H spectrum…

Using Keck laser guide star adaptive optics imaging, we have found that the T9 dwarf WISE J1217+1626 and T8 dwarf WISE J1711+3500 are exceptional binaries, with unusually wide separations (~0.8 arcsec, 8-15 AU), large near-IR flux ratios…

Hierarchical massive quadruple systems are ideal laboratories for examining the theories of star formation, dynamical evolution, and stellar evolution. The successive mergers of hierarchical quadruple systems might explain the mass gap…

FU Tau belongs to a rare class of young, wide brown dwarf binaries. We have resolved the system in a Chandra X-ray observation and detected only the primary, FU Tau A. Hard X-ray emission, presumably from a corona, is present but,…

HD~69479/80 is a composite-spectrum binary whose components are a late-G giant and an early-A dwarf. The orbit has a period of only 91 days (which seems short for a system containing a cool giant with a radius of $\sim$13 solar radii), and…

Neutron stars and stellar-mass black holes are the remnants of massive stars, which ended their lives in supernova explosions. These exotic objects can only be studied in relatively rare cases. If they are interacting with close companions…

The planet-hosting and Sirius-type binary system epsilon Reticulum (HD 27442) is examined from the perspective of its more evolved white dwarf secondary. The stellar parameters are determined from a combination of Balmer line spectroscopy,…

We report the discovery of a nearby massive white dwarf with He-H atmosphere. The white dwarf is located at a distance of $74.5\pm0.9$ pc. Its radius, mass, effective temperature, H/He ratio and age are $R=2500\pm100$ km, $M=1.33\pm0.01$…

J191213.72-441045.1 is a binary system composed of a white dwarf and an M-dwarf in a 4.03-hour orbit. It shows emission in radio, optical, and X-ray, all modulated at the white dwarf spin period of 5.3 min, as well as various orbital…

We present analysis of Hubble Space Telescope images of 82 nearby field late-M and L dwarfs. We resolve 13 of these systems into double M/L dwarf systems and identify an additional possible binary. Combined with previous observations of 20…

We look for wide, faint companions around members of the 5 Myr Lambda Orionis open cluster. We used optical, near-infrared, and Spitzer/IRAC photometry. We report the discovery of a very wide very low mass visual binary, LOri167, formed by…

We carried out low resolution spectroscopic observations in the wavelength range 3400-4700 A of 20 He-weak and 8 He-strong stars to determine their fundamental parameters by means of the Divan-Chalonge-Barbier (BCD) spectrophotometric…

We report the discovery of an eclipsing binary -- PTF1 J072456$+$125301-- composed of a subdwarf B (sdB) star ($g'=17.2^m$) with a faint companion. Subdwarf B stars are core helium-burning stars, which can be found on the extreme horizontal…

The variable source OGLE-UCXB-01 is the first OGLE-discovered ultracompact X-ray binary (UCXB). The 12-year long-term OGLE optical photometry of this source shows a period of P= 12.8 min and a fast period decreasing rate Pdot= -9.2E-11 s…

We report the analysis of high-resolution, high-S/N spectra of an extremely metal-poor, extremely C-rich red giant, Seg 1-7, in the Segue 1 system - described in the literature alternatively as an unusually extended globular cluster or an…

Two Chandra observations of the R Aqr symbiotic binary system taken 3.3 years apart show dramatic changes in the X-ray morphology and spectral characteristics in the inner 500 AU of this system. The morphology of the soft X-ray emission has…

We provide a detailed characterization of 2M07515777+1807352, a post-common envelope eclipsing binary system with a 10.3 d, nearly, but not quite, circular orbit (e = 0.02). This system consists of a massive white dwarf (WD) ($1.08$…

Using astrometric measurements obtained with the FORS2/VLT camera, we are searching for low-mass companions around 20 nearby ultracool dwarfs. With a single-measurement precision of 0.1 milli-arcseconds, our survey is sensitive to a wide…

The origin of hot subdwarf B stars (sdBs) is still unclear. About half of the known sdBs are in close binary systems for which common envelope ejection is the most likely formation channel. Little is known about this dynamic phase of binary…

We report on a high-resolution, spectroscopic stellar parameter and abundance analysis of a d' symbiotic star: the yellow component of StH\alpha190. This star has recently been discovered, and confirmed here, to be a rapidly rotating…