相关论文: A High Contrast Imaging Survey of SIM Lite Planet …

We present spectra of 59 nearby stars candidates, M dwarfs and white dwarfs, previously identified using high proper motion catalogues and the DENIS database. We review the existing spectral classification schemes and spectroscopic parallax…

We present the results of a medium resolution optical spectroscopic survey of 92 cool ($3,000 \lesssim T_{\rm eff} \lesssim 4,500\,$K) southern TESS candidate planet hosts, and describe our spectral fitting methodology used to recover…

The results of speckle interferometric observations of 104 binary and 6 triple stars performed at the BTA 6 m telescope in 2004 October are presented. Nearby low-mass stars are mostly observed for the program, among which 59 there are new…

Spectral characterization of sub-stellar companions is essential to understand their composition and formation processes. However, the large contrast ratio of the brightness of each object to that of its parent star limits our ability to…

Given the frequency of stellar multiplicity in the solar neighborhood, it is important to study the impacts this can have on exoplanet properties and orbital dynamics. There have been numerous imaging survey projects established to detect…

For the last three years we have performed a survey for young (<3 Gyrs) giant planets around nearby white dwarfs with HST, Spitzer, and VLT. Direct HST/NICMOS imaging of the seven white dwarfs in the Hyades gave no evidence for companions…

So far, most of the about 5700 exoplanets have been discovered mainly with radial velocity and transit methods. These techniques are sensitive to planets in close orbits, not being able to probe large star--planet separations. $\mu$-lensing…

Precise mass constraints are vital for the characterisation of brown dwarfs and exoplanets. Here we present how the combination of data obtained by Gaia and GRAVITY can help enlarge the sample of substellar companions with measured…

By combining the JWST/NIRCam JADES and CEERS extragalactic datasets, we have uncovered a sample of twenty-one T and Y brown dwarf candidates at best-fit distances between 0.1 - 4.2 kpc. These sources were selected by targeting the blue…

We present the results of a HST/NICMOS coronagraphic survey for the direct detection of substellar companions within the young TW Hydrae and Tucana Associations. At the distance of these associations, the lower mass limit of detection,…

We have carried out an L' and M band Adaptive Optics (AO) extrasolar planet imaging survey of 54 nearby, sunlike stars using the Clio camera at the MMT. Our survey concentrates more strongly than all others to date on very nearby F, G, and…

The direct imaging of rocky exoplanets is one of the major science goals for upcoming large telescopes. The contrast requirement for imaging such planets is challenging. However, the mid-IR (InfraRed) regime provides the optimum contrast to…

We report the results of our HST snapshot survey with the ACS HRC PR200L prism, designed to measure the near-UV emission in a sample of nearby M dwarfs. 33 stars were observed, spanning the mass range from 0.1 - 0.6 solar masses (T_eff ~…

Almost all massive stars are part of a binary system. Given the wide range of separations at which these companions are found, several observational techniques have been adopted to characterize them, but contrasts greater than 4 in the…

Studies of solar twins have key impacts on the astronomical community, but only $\sim$100--200 nearby solar twins ($<$ 1 kpc) have been reliably identified over the last few decades. The aim of our survey (SDST) is to identify…

Zechmeister et al. (2009) surveyed 38 nearby M dwarfs from March 2000 to March 2007 with VLT2 and the UVES spectrometer. This data has recently been reanalyzed (Butler et al. 2019), yielding a significant improvement in the Doppler velocity…

We present initial results from a new high-contrast imaging program dedicated to stars that exhibit long-term Doppler radial velocity accelerations (or "trends"). The goal of the TRENDS (TaRgetting bENchmark-objects with Doppler…

Breakthrough direct detections of planetary companions orbiting A-type stars confirm the existence of massive planets at relatively large separations, but dedicated surveys are required to estimate the frequency of similar planetary…

We present the results of an all-sky survey made with the Fine Guidance Sensor on Hubble Space Telescope to search for angularly resolved binary systems among the massive stars. The sample of 224 stars is comprised mainly of Galactic O- and…

We analyse 11 years of precise radial velocities for 76 solar type stars from the Lick survey. Eight stars in this sample have previously reported planetary-mass companions, all with mass (m sin i) less than 8 Jupiter masses (MJ). For the…