The lightcurve of the Large Magellanic Cloud (LMC) variable star MACHO 81.8997.87 shows evidence for photometric variations due to both stellar pulsation, with a 2.035 day period, and eclipsing behavior, with an 800.4 day period. The primary star of the system has been identified as a first-overtone Cepheid but the nature of the secondary star has not been determined. Here we present multicolor...

Detailed surface photometry has been carried out for three barred galaxies with use of high resolution CCD broadband images in the B, V and I bands. Using azimuthal luminosity profiles and their decomposition into Fourier Series, the structural parameters (length and strength) of the bars in the three galaxies have been obtained. We have also inferred the corotation radii (CR) using information...

This paper is a study of the mass distribution in the central 35 ≃ 1.7 kpc of the E5 galaxy NGC 3377. Stellar rotation velocity and velocity dispersion profiles (seeing σ∗ = 0. 20 – 0. 56) and V -band surface photometry (σ∗ = 0. 20 – 0. 26) have been obtained with the Canada-France-Hawaii Telescope. NGC 3377 is kinematically similar to M32: the central kinematic gradients are steep. There is an...

We study the properties of satellites in the environment of massive star-forming galaxies at z ∼ 1.8 in the COSMOS field, using a sample of 215 galaxies on the main sequence of star formation with an average mass of ∼1011 M . At z > 1.5, these galaxies typically trace halos of mass 10 M . We use optical-near-infrared photometry to estimate stellar masses and star formation rates (SFR) of centra...

We present a comprehensive study of the z = 0.43 host galaxy of GRB 990712, involving ground-based photometry, spectroscopy, and HST imaging. The broad-band UBVRIJHKs photometry is used to determine the global spectral energy distribution (SED) of the host galaxy. Comparison with that of known galaxy types shows that the host is similar to a moderately reddened starburst galaxy with a young ste...

Gravitational microlensing provides a new technique for studying the surfaces of distant stars. Microlensing events are detected in real time and can be followed up with precision photometry and spectroscopy. This method is particularly adequate for studying red giants in the Galactic Bulge. We show that different properties of the stellar surface can be recovered from timedependent photometry ...