Related papers: MACHO 311.37557.169: A VY Scl star

The spectrum of the recently discovered cataclysmic variable star (CV) ASAS-SN 13cl shows that a secondary star with spectral type K4 (+- 2 subclasses) contributes roughly half the optical light. The radial velocities of the secondary are…

We identify the likely optical counterpart to the LMC supersoft X-ray source RXJ0527.8-6954, and hence recover HV2554. This identification is based on an analysis of approximately 4 years of optical photometry obtained serendipitously via…

The MACHO Project is a microlensing survey that monitors the brightnesses of 60 million stars in the Large Magellanic Cloud (LMC), Small Magellanic Cloud, and Galactic bulge. Our database presently contains about 80 billion photometric…

Two recently discovered variable stars (CzeV134 = GSC 3682 0018 = USNO-A2.0 1425-1870026 and CzeV135 = GSC 3682 2051 = USNO-A2.0 1425-1825909 = V1094 Cas), which have been identified in the field of the W UMa variable star BS Cas, are…

We present further results from a high speed photometric survey of faint cataclysmic variables. We find that V842 Cen (Nova Cen 1986 No. 2) is highly active, but with no evident orbital modulation. BY Cir (Nova Cir 1995) is an eclipsing…

We present the first observations of magnetic cataclysmic variables with the Spitzer Space Telescope. We used the Infrared Array Camera to obtain photometry of the polars EF Eri, GG Leo, V347 Pav, and RX J0154.0-5947 at 3.6, 4.5, 5.8, and…

Very massive stars (VMS) are defined as stars with an initial mass in excess of 100 Msun. Because of their short lifetime and the shape of the stellar mass function, they are rare objects. Only about twenty of them are known in the Galaxy…

Variability of millimetre wavelength continuum emission from Class II protoplanetary disks is extremely rare, and when detected it is usually interpreted as originating from non-thermal emission mechanisms that relate to the host star…

We present new observations of the red supergiant VY CMa at 1.25 micron, 1.65 micron, 2.26 micron, 3.08 micron and 4.8 micron. Two complementary observational techniques were utilized: non-redundant aperture masking on the 10-m Keck-I…

Aims: We test the technique of spectro-astrometry as a potential method to investigate the close environment of massive young stars. Method: Archival VLT near infrared K band spectra (R=8900) of three massive young stellar objects and one…

If the dark halo matter is primarily composed of MACHOs toward the lower end of the possible detection range ($ < 10^{-3}$ $M_{\odot}$) a fraction of the lens detection events should involve the lens crossing directly in front of the disk…

Stars exhibit a bewildering variety of variable behaviors ranging from explosive magnetic flares to stochastically changing accretion to periodic pulsations or rotations. The principal LSST surveys will have cadences too sparse and…

We report follow-up observations of five cataclysmic variable candidates from LAMOST published by Hou et al. (2020). LAMOST J024048.51+195226.9 is the most unusual of the five; an early-M type secondary star contributes strongly to its…

Vista Variables in the Via Lactea (VVV) is an ESO Public Survey that is performing a variability survey of the Galactic bulge and part of the inner disk using ESO's Visible and Infrared Survey Telescope for Astronomy (VISTA). The survey…

The MACHO project is a search for dark matter in the form of massive compact halo objects (MACHOs). The project has photometrically monitored tens of millions of stars in the Large Magellanic Cloud (LMC), Small Magellanic Cloud (SMC), and…

The central star of NGC 2392 shows the hardest X-ray emission among central stars of planetary nebulae (CSPNe). The recent discovery of a spectroscopic companion with an orbital period of 1.9 days could provide an explanation for its hard…

We present low resolution optical spectroscopy for six cataclysmic variable candidates and the old nova V888 Cen. We confirm the classification as cataclysmic variable for LB 9963 and FQ Mon, while the other four candidates turn out to be…

The MACHO collaboration reports on the analysis of our first year LMC data, 9.5 million light curves with an average of 235 observations each. Automated selection procedures give 3 events consistent with microlensing. We evaluate our…

We have used Spitzer/IRAC to conduct a photometric monitoring program of the IC1396A dark globule in order to study the mid-IR (3.6 - 8 micron) variability of the heavily embedded Young Stellar Objects (YSOs) present in that area. We…

This paper presents a photometric and spectroscopic study of the bright blue eclipsing binary LMC-SC1-105, selected from the OGLE catalog as a candidate host of very massive stars (>=30Mo). The system is found to be a double-lined…