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W 601 (NGC 6611 601) is one of the handful of known magnetic Herbig Ae/Be stars. We report the analysis of a large dataset of high-resolution spectropolarimetry. The star is a previously unreported spectroscopic binary, consisting of 2 B2 stars with a mass ratio of 1.8, masses of 12 M$_odot$ and 6.2 $M_odot$, in an eccentric 110-day orbit. The magnetic field belongs to the secondary, W 601 B. The H$alpha$ emission is consistent with an origin in W 601 Bs centrifugal magnetosphere; the star is therefore not a classical Herbig Be star in the sense that its emission is not formed in an accretion disk. However, the low value of $log{g} = 3.8$ determined via spectroscopic analysis, and the stars membership in the young NGC 6611 cluster, are most consistent with it being on the pre-main sequence. The rotational period inferred from the variability of the H$alpha$ line and the longitudinal magnetic field $langle B_z rangle$ is 1.13 d. Modelling of Stokes $V$ and $langle B_z rangle$ indicates a surface dipolar magnetic field $B_{rm d}$ between 6 and $11$ kG. With its strong emission, rapid rotation, and strong surface magnetic field, W 601 B is likely a precursor to H$alpha$-bright magnetic B-type stars such as $sigma$ Ori E. By contrast, the primary is an apparently non-magnetic ($B_{rm d} < 300$ G) pre-main sequence early B-type star. In accordance with expectations from magnetic braking, the non-magnetic primary is apparently more rapidly rotating than the magnetic star.
We present Mon-735, a detached double-lined eclipsing binary (EB) member of the $sim$3 Myr old NGC 2264 star forming region, detected by Spitzer. We simultaneously model the Spitzer light curves, follow-up Keck/HIRES radial velocities, and the system
We present results from long-term optical photometric and spectroscopic observations of 5 pre-main sequence stars, located in the vicinity of the bight nebula NGC 7129. We obtained UBVRI photometric observations in the field centered on the star V391
The young system RX J0529.3+1210 was initially identified as a single-lined spectroscopic binary. Using high-resolution infrared spectra, acquired with NIRSPEC on Keck II, we measured radial velocities for the secondary. The method of using the infra
We report the discovery of two young M-dwarfs, RX J0942.7-7726 (M1) and 2MASS J09424157-7727130 (M4.5), that were found only 42 arcsec apart in a survey for pre-main sequence stars surrounding the open cluster eta Chamaeleontis. Both stars have congr
We present results of multi-epoch (fourteen nights during 2007-2010) $V$-band photometry of the cluster NGC 1893 region to identify photometric variable stars in the cluster. The study identified a total of 53 stars showing photometric variability. T