TD-1 Satellite Research Articles

A Discussion on astronomy in the ultraviolet - Preliminary results of ultraviolet interstellar extinction from TD1 satellite observations

The interstellar extinction law in the far ultraviolet has been derived from observations of about 100 stars for three galactic regions in the direction of Cygnus, galactic centre and anticentre. For each region the weighted mean extinction curve has an accuracy of about 6 % and shows no variation for the different directions. The profile of the broad extinction band centred near 2200 A is derived and shown to be symmetrical. It is concluded that the extinction characteristics will need more than one type of particle for their explanation.

Ultraviolet energy distributions of luminous early-type stars from TD1 satellite observations

view Abstract Citations (28) References (14) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Ultraviolet energy distributions of luminous early-type stars from TD1 satellite observations. Humphries, C. M. ; Nandy, K. ; Kontizas, E. Abstract Ultraviolet spectra are presented for supergiants, giants, and main-sequence stars in the spectral type range from B0 to A2. The observations were obtained in the spectral range A with the S2/68 Ultraviolet Sky Survey Telescope in the TD1 satellite. The effect of luminosity has been studied by comparing the ultraviolet energy distributions of luminous and main-sequence stars of the same spectral type. The flux deficiencies which are observed in the energy distributions of luminous stars are interpreted as the result of lower effective temperatures for luminous stars than for corresponding main-sequence stars, and an estimate is given of the effective temperature scale for B-type supergiants. Subject headings: early-type stars - spectra, ultraviolet - spectrophotometry Publication: The Astrophysical Journal Pub Date: January 1975 DOI: 10.1086/153310 Bibcode: 1975ApJ...195..111H Keywords: Early Stars; Energy Spectra; Spaceborne Astronomy; Stellar Spectrophotometry; Ultraviolet Spectra; Satellite Observation; Stellar Luminosity; Ubv Spectra; Ultraviolet Radiation; Space Radiation full text sources ADS | data products SIMBAD (22)

Photometric measurements of the O 2 U.V. nightglow

Measurements of the O 2( A 3 Σ − X 3 Σ) Herzberg system in the night airglow have been made with the ESRO TD-1 satellite in the wavelength range 2400–3100 A. The slant emission rate varies from 3.5 to 15 kR, indicating an irregular structure of the atomic oxygen near the turbopause. A statistical maximum intensity is found near the tropic in the winter hemisphere. The intensity profile is consistent with excitation by three-body recombination of oxygen atoms. The observed total emission rate can be accounted for by reasonable atomic oxygen densities and an O 2( A 3 Σ) production efficiency of about 20% if quenching by N 2 occurs at the rate deduced from laboratory and other airglow measurements.

Early Data from the Ultraviolet Sky-scan Telescope in the TD1 Satellite

An initial examination of data from the TD1 satellite telescope shows it to be functioning satisfactorily. The spectra observed are in good agreement with information obtained from rocket-borne telescopes.