Calculations of atmospheric transmission through the M (5 microns) atmospheric window, at a resolution of 10 to the 3rd power are presented for sites at the Observatorio del Teide, Tenerife and the NHO, La Plama in the Canary Islands. We use a standard midlatitude atmospheric model and absorption line strengths for the known molecular species

The 2(1,1) - 2(1,2) rotational transition of HDO has been detected towards the KL position at the center of the OMC-1 at a velocity of +5.5(+ or - 1.3)km/s, corresponding to emission from the central core. This measurement is combined with previous estimates of the H2O abundance close to KL to obtain a ratio of the concentration of HDO to that of

Position data of sunspot groups from the period 1874-1902 are used to investigate the differential rotation of the Sun and the meridional motions of the sunspots. The equatorial velocity is higher than in the period 1940-1968 investigated by Balthasar and Wöhl (1980), while differences between the northern and southern hemispheres are less. For

The 1-8A band of synodic full-disc solar X-rays (1-8A) W/m(2) were measured nearly continuously from 1975 to 1981 aboard the SMS-1, SMS-2, GOES-1, GOES-2, and GOES-3 satellites. The 1-8A band of X-rays are proportional to the emission measure at coronal heights at temperatures greater than 2,000,000 K. A practical method of describing solar 1-8A

The IUE observed AB Aur, HD250550, and BD + 46 deg 3471 at high resolution in the range 2000 to 32000 A. The MgII resonance line profiles all show a P Cygni structure, with an intense emission, and a shortward wing velocity in the absorption component of 300 to 600 km/sec. In HD 250550, the Fe II line spectrum exhibits a shell phenomenon: all lines

Spectra of six main sequence stars with spectral types from F0 to G8 were obtained with the IUE long wavelength spectrograph at high resolution. Four or more spectra of each object were taken over a period of 3.5 years, supplemented by archive spectra from IUE of the same type. Quantitative analysis of the Mg II h and k emission cores from these