Related papers: The young low-mass star ISO-Oph-50: Extreme variab…
It is now well established that many young brown dwarfs exhibit characteristics similar to classical T Tauri stars, including infrared excess from disks and emission lines related to accretion. Whether the same holds true for even lower…
Young stars exhibit short-term photometric variability caused by mass accretion events from circumstellar disks, the presence of dusty warps within the inner disks, starspots that rotate across the stellar surfaces, and flares. Long-term…
The continuous temporal coverage and high photometric precision afforded by space observatories has opened up new opportunities for the study of variability processes in young stellar cluster members. Of particular interest is the…
Infrared observations can probe photometric variability across the full evolutionary range of young stellar objects (YSOs), from deeply embedded protostars to pre-main-sequence stars with dusty disks. We present 3-8 micron light curves…
We have carried out a near-infrared imaging survey of luminous young stellar outflow candidates using the United Kingdom Infrared Telescope. Observations were obtained in the broad band K (2.2 mu) and through narrow band filters at the…
We searched the light curves of over 40000 stars in the 2MASS calibration database, spanning approximately 4 years, for objects that have significant day long dimming events. We also searched the multi-color light curves for red dimming…
Our goal is to study the physical properties of the circumstellar environment of young stellar objetcs (YSOs). In particular, the determination of the scattering mechanism can help to constrain the optical depth of the disk and/or envelope…
New multi-epoch, mid-infrared (8-13 microns) spectrophotometric observations are presented for 30~late-type stars. The observations were collected over a four year period (1994-1997), permitting an investigation of the mid-infrared spectral…
Presented are the results of a near-IR photometric survey on 1678 stars in the direction of the \rho Ophiuchus (\rho Oph) star forming region using data from the 2MASS Calibration Database. For each target in this sample, up to 1584…
We present near-infrared (1.0-2.4 micron) spectra confirming the youth and cool effective temperatures of 6 brown dwarfs and low mass stars with circumstellar disks toward the Chamaeleon II and Ophiuchus star forming regions. The spectrum…
We present the characterization of the low-gravity M6 dwarf 2MASS J0619-2903 previously identified as an unusual field object based on its strong IR excess and variable near-IR spectrum. Multiple epochs of low-resolution (R~150) near-IR…
We present the results of photometric and spectroscopic follow-ups of the lowest mass member candidates in the nearest OB association, Upper Scorpius (5-10 Myr; 145+/-17 pc), with the Gran Telescopio de Canarias (GTC) and European Southern…
The emission from young stellar objects (YSOs) in the mid-IR is dominated by the inner rim of their circumstellar disks. We present an IR-monitoring survey of about 800 objects in the direction of the Lynds 1688 (L1688) star forming region…
Environmental effects, such as stellar fly-bys and external irradiation, are thought to affect the evolution of protoplanetary disks in clustered star formation. Previous ALMA images at 225 GHz of the ISO-Oph 2 binary revealed a peculiar…
New infrared and millimeter observations from Keck, Palomar, ISO, and OVRO and archival data from the NRAO VLA and IRAS are presented for the low metallicity blue compact dwarf galaxy SBS 0335-052. Mid-infrared imaging shows this young…
Because of the intense brightness of the OB-type multiple star system sigma Ori, the low-mass stellar and substellar populations close to the centre of the very young sigma Orionis cluster is poorly know. I present an IJHKs survey in the…
The theory of massive star formation currently suffers from a scarce observational base of massive young stellar objects to compare with. In this paper, we present OVRO CO(1-0), 13CO(1-0), C18O(1-0), and 2.6 mm continuum images of the…
We have obtained time series observations of the Orion Nebula Cluster at 70 microns and 160 microns from the Herschel/PACS Photometer. This represents the first wide-field far-infrared photometric monitoring of a young star forming region.…
Herbig-Haro objects (HHOs) are caused by outflows from young objects. Since the outflow relies on mass accretion from a circumstellar disk, it indicates ongoing growth. Recent results of infrared observations yielded evidence for disks…
The aim of this work is to identify the so far unknown low mass stellar population of the ~2Myr old Cygnus OB2 region, and to investigate the X-ray and near-IR stellar properties of its members. We analyzed a 97.7 ksec Chandra ACIS-I…