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Comet Halley-solar wind interaction from electron measurements aboard Giotto
Anderson, K. A.; Reme, H.; Korth, A. +9 more
Measurements made by the three-dimensional electron spectrometer of the RPA-Copernic experiment aboard the Giotto spacecraft give a preliminary description of the complex interaction between comet Halley and the solar wind. As Giotto approached the comet, it traversed several regions of differing plasma characteristics: a large (~107 km…
Coordinated Exosat and spectroscopic observations of flare stars and coronal heating
Foing, B. H.; Rodono, M.; Butler, C. J. +1 more
The X-ray flux of dMe stars is thought to arise from two distinct mechanisms, one involving a continuous `quiescent' emission from a high-temperature plasma and the other involving the dramatic flare events which have long been known to occur on these stars. We present here some results of simultaneous monitoring of the two flare stars, UV Ceti an…
Post-perihelion observations of water in comet Halley
Weaver, H. A.; Davis, D. S.; Mumma, M. J. +1 more
Our previous pre-perihelion observations1 of comet Halley from the NASA Kuiper Airborne Observatory (KAO) resulted in the first definite detection of water vapour in a comet. This success allowed us to carry out an ambitious post-perihelion KAO observing programme which significantly extended the scope of our Halley water investigation.…
Mass spectra of heavy ions near comet Halley
Anderson, K. A.; Reme, H.; Korth, A. +10 more
The heavy-ion analyser, RPA2-PICCA, aboard the Giotto spacecraft, detected the first cometary ions at a distance of ~1.05×106 km from the nucleus of comet Halley. In the inner coma the major ions identified are associated with the H2O, CO and CO2 groups. Ions of larger atomic mass unit are also present, correspondi…
Is CO2 responsible for the outbursts of comet Halley?
Feldman, P. D.; A'Hearn, M. F.; Weaver, H. A. +3 more
Outbursts are thought to originate from the nucleus of comet Halley; cameras on the Vega and Giotto spacecraft have recorded the images of jets1,2, and rapid fluctuations are seen in the visible light curve, detected, for example, by the International Ultraviolet Explorer satellite during the time the spacecraft were making their observ…
Optical probing of comet Halley from the Giotto spacecraft
Llebaria, A.; Lamy, P.; Bertaux, J. L. +7 more
The Halley optical probe experiment (HOPE) aboard the Giotto spacecraft has provided the first measurements of the optical properties of the dust and of some gaseous species (CN, C2, CO+ and OH) from inside the coma of comet Halley. The dust spatial distribution, inferred from sunlight scattering, obeys an r-2 law …
The historical record for Sirius: evidence for a white-dwarf thermonuclear runaway?
Sion, Edward M.; Kondo, Yoji; Bruhweiler, Frederick C.
Schlosser and Bergmann1 recently presented evidence that in medieval times Sirius was a bright red star, rather than the present bluish-white star, from which they have suggested that Sirius B is a recently born white dwarf. However, their model poses severe evolutionary problems. We present the results of our attempts to detect possibl…
Space observations of comet Halley
Brandt, J. C.
Following the encounters by Soviet, Japanese and European spacecraft, the International Cometary Explorer took measurments of comet Halley on 22 March. The comet has also been observed by the Solar Maximum Mission, the International Ultraviolet Explorer, the Pioneer Venus Orbiter, the Dynamics Explorer 1, and by sounding rockets.
New results from Exosat
Fabian, A. C.