We have used a flux-calibrated mosaiced CCD image of M33 in Hα emission to produce a catalogue of the positions and Hα luminosities of 9190 HII regions complete down to a limiting luminosity LHα of 1036 erg/s and constructed a luminosity function (LF) from this catalogue. In contrast to previously published M33 LFs we find the slope of the function

Spectroscopic observations of this X-ray nova with the new 6.5-m MMT on Dec. 1 & 4 show that it contains a black hole primary of at least 6 solar masses. Our prior photometric observations using the FLWO 1.2-m telescope showed that the X-ray nova was near its pre-outburst brightness (IAUC 7390) at V = 18.8 on Oct. 26.

Spectroscopic observations of the fast X-ray transient and superluminal jet source SAX J1819.3-2525 (V4641 Sgr) reveal a best fitting period of P spect=2.81678+/- 0.00056 days and a semiamplitude of K2=211.0+/- 3.1 km s-1. The optical mass function is f(M)=2.74+/- 0.12 Msun. We find a photometric period of P photo=2.81730 +/- 0.00001 days using a

VII Zw403 is a nearest BCD galaxy. This izolated system is so close (~4.5 Mp c), that it makes it possible to study it's star forming regions with unprecedently great details. recent X-ray observations (Papaderos et al. 1994) added more interest to the system, as revealed an extended, kpc-scale region of the diffuse X-ray emission. We use our

Here is a state-of-the-art review of our current knowledge of brown dwarfs and very low-mass stars. The hunt for, and study of, these elusive objects is currently one of the most dynamic areas of research in astronomy. This volume presents review articles from a team of international authorities who assess the spectacular progress in this field in

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