Related papers: Substellar Mass Function of Young Open Clusters as…
We make use of new near and mid-IR photometry of the Pleiades cluster in order to help identify proposed cluster members. We also use the new photometry with previously published photometry to define the single-star main sequence locus at…
We investigated the stellar mass function and the binary fraction of 114 nearby open clusters (OCs) using the high-precision photometric data from Gaia Data Release 3 (Gaia DR3). We estimated the mass of member stars by using a ridge line…
We investigate the low-mass population of the young cluster IC348 down to the deuterium-burning limit, a fiducial boundary between brown dwarf and planetary mass objects, using a new and innovative method for the spectral classification of…
The origin of the lowest mass free-floating objects -- brown dwarfs and planetary-mass objects -- is one of the major unsolved problems in star formation. Establishing a census of young substellar objects is a fundamental prerequisite for…
We present the results of a 6.4 square degrees imaging survey of the Pleiades cluster in the I and Z-bands. The survey extends up to 3 degrees from the cluster center and is 90% complete down to I~22. It covers a mass range from 0.03 Msun…
In this paper we present surveys of two open clusters using photometry and accurate astrometry from the SuperCOSMOS microdensitometer. These use plates taken by the Palomar Oschin Schmidt Telescope giving a wide field ($5^{\circ}$ from the…
We present $UBVI_c$ CCD photometry of the young open cluster Stock 8 with the aim to study the basic properties and star formation scenario in this region. The radius of the cluster is found to be $\sim 6^{\prime}$ ($\sim 3.6$ pc) and the…
NGC6357 is an active star forming region with very young massive open clusters (OC). These clusters contain some of the most massive stars in the Galaxy and strongly interact with nearby giant molecular clouds (GMC). We study the young…
The nearby young sigma Orionis cluster (~360 pc, ~3 Ma) is becoming one of the most important regions for the study of ultra low-mass star formation and its extension down to the mass regimes of the brown dwarfs and planetary-mass objects.…
We have obtained images of the Trapezium Cluster (140" x 140"; 0.3 pc x 0.3 pc) with the Hubble Space Telescope Near-Infrared Camera and Multi-Object Spectrometer (NICMOS). Combining these data with new ground-based K-band spectra (R=800)…
We investigate the nature of 4 young and low-mass open clusters (OCs) located in the $2^{nd}$ and $3^{rd}$ quadrants with near-IR 2MASS photometry (errors $<0.1$ mag). After field decontamination, the colour-magnitude diagrams (CMDs)…
Two stellar-dynamical models of binary-rich embedded proto-Orion-Nebula-type clusters that evolve to Pleiades-like clusters are studied with an emphasis on comparing the stellar mass function with observational constraints. By the age of…
We performed a deep wide field optical survey of the young (~100-150 Myr) open cluster Blanco1 to study its low mass population well down into the brown dwarf regime and estimate its mass function over the whole cluster mass range.The…
SONYC - Substellar Objects in Nearby Young Clusters - is a survey program to investigate the frequency and properties of substellar objects with masses down to a few times that of Jupiter in nearby star-forming regions. In this third paper,…
SONYC -- Substellar Objects in Nearby Young Clusters -- is a program to investigate the frequency and properties of young substellar objects with masses down to a few times that of Jupiter. Here we present a census of very low mass objects…
The supermassive black hole at the center of the Milky Way plays host to a massive, young cluster that may have formed in one of the most inhospitable environments in the Galaxy. We present new measurements of the global properties of this…
We provide a review of the current status of several topics on the ages, distances, and mass functions of open clusters, with a particular emphasis on illuminating the areas of uncertainty. Hipparcos has obtained parallaxes for nearby open…
The solar neighbourhood is populated by nearby, young moving groups (NYMGs) of stars that are candidates to be remnants of individual stellar clusters and associations, currently dispersing in the galactic disc. To derive the initial mass…
A new X-ray selected and X-ray flux-limited galaxy cluster sample is presented. Based on the ROSAT All-Sky Survey the 63 brightest clusters with galactic latitude |bII| >= 20 deg and flux fx(0.1-2.4 keV) >= 2 * 10^{-11} ergs/s/cm^2 have…
Substellar Objects in Nearby Young Clusters -- SONYC -- is a survey program to investigate the frequency and properties of substellar objects in nearby star-forming regions. We present new spectroscopic follow-up of candidate members in…