Results 231 to 240 of about 378,163 (279)
Some of the next articles are maybe not open access.
Galactic ultraviolet astronomy
Reports on Progress in Physics, 1987A general presentation of astrophysical observations in the ultraviolet is given. First the particular nature of ultraviolet studies is emphasises. This is followed by a brief historical presentation of some of the typical instrumentation used. Then, in the framework of galactic observations, some of the most important results obtained concerning the ...
A Vadal-Madjar +5 more
openaire +1 more source
Ultraviolet astronomy enters the eighties
Physics Today, 1980Ultraviolet astronomy, once the province of instrumentalists, has become an accessible and necessary technique for all astronomers. In the first three years after the 1972 launch of the Copernicus satellite about 100 astronomers used its ultraviolet-spectrometer data, outnumbering by a factor of ten the core group of Princeton University scientists who
Albert Boggess, Stephen P Maran
exaly +2 more sources
Aspheric grating for extreme ultraviolet astronomy
Applied Optics, 1978A family of plane curves is developed which can diffract incident parallel rays to a point focus. These curves, termed diffractoidal curves, are rotated around an axis to produce surfaces of revolution correspondingly termed diffractoids, whose imaging properties for sources at infinity are studied by ray tracing in a few examples.
S O, Kastner, C, Wade
openaire +2 more sources
A Discussion on astronomy in the ultraviolet - A search for ultraviolet objects
Philosophical Transactions of the Royal Society of London. Series A, Mathematical and Physical Sciences, 1975Abstract The observations of the sky-survey telescope in the TD-1A satellite are being searched for ultraviolet objects. The first results, covering about 10 % of the sky, are presented and rough limits on space density and luminosity are derived.
D. J. Carnochan +4 more
openaire +1 more source
Scientific American, 1994
▪ Abstract Astronomical studies in the extreme ultraviolet (EUV) band of the spectrum were dismissed during the early years of space astronomy as impossible, primarily because of the mistaken view that radiation in this band would be absorbed by the interstellar medium.
openaire +1 more source
▪ Abstract Astronomical studies in the extreme ultraviolet (EUV) band of the spectrum were dismissed during the early years of space astronomy as impossible, primarily because of the mistaken view that radiation in this band would be absorbed by the interstellar medium.
openaire +1 more source
Astronomy and the Extreme Ultraviolet Explorer satellite
Science, 1994The extreme ultraviolet wave band (100 to 912 angstroms) was thought until recently to be useless to astronomy, primarily because the opacity of the interstellar medium would prevent observations at these wavelengths. However, the interstellar medium has been found to be markedly inhomogeneous in both density and ionization state and the sun is ...
openaire +2 more sources
A Discussion on astronomy in the ultraviolet - Stellar studies in the balloon ultraviolet
Philosophical Transactions of the Royal Society of London. Series A, Mathematical and Physical Sciences, 1975Abstract Observations with a spectral resolution of 0.01 nm have been made for several stars in the balloon ultraviolet. For the two coolest stars studied ((3 Ori and a Lyr) wavelengths of all observed spectral features in the range 273-288 nm are given with an accuracy of approximately ± 0.004 nm.
B. Bates +6 more
openaire +1 more source
Skylab ultraviolet stellar astronomy experiment S019
Applied Optics, 1977An objective-prism stellar spectrograph of 15-cm aperture was flown on all three Skylab missions. The wavelength region from 1300 A to 5000 A was covered by a special optical system containing a combination of reflecting telescope optics, a CaF(2) objective prism, and an achromatized field corrector lens system of CaF(2) and LiF.
F G, O'Callaghan, K G, Henize, J D, Wray
openaire +2 more sources
A Discussion on astronomy in the ultraviolet - Interstellar gas studies in the balloon ultraviolet
Philosophical Transactions of the Royal Society of London. Series A, Mathematical and Physical Sciences, 1975Abstract Spectral observations at a resolution of 0.1 A covering the region 2870—2740 A have been made of several stars with an objective grating spectrograph mounted on a balloon-borne star-stabilized platform. We report our measurements of the interstellar lines of Mg II at 2795.53 A and 2802.70 A and Mg i at 2852.13 A.
A. Boksenberg +8 more
openaire +1 more source
Ultraviolet, optical and infrared astronomy
Physics Today, 1982While it is possible to trace the history of ultraviolet, optical and infrared astronomy to an era before that of the pre-Christian Greek astronomers at Alexandria, the field is not as static as this maturity might suggest. The flowering of space astronomy and the orders-of-magnitude improvement in detector technology give us exploratory capabilities ...
openaire +1 more source