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The Near-Nuclear Coma of Comet Halley in March 1986
Fulle, Marco; Szegö, Karoly; Crifo, Jean-François +1 more
The cameras carried onboard the flyby missions to comet P/Halleyin 1986 imaged the near nuclear jet activity fromseveral spatial directions. The observed, very structured near nucleardust jets were considered at that timeas the result of dust emission from well localized active surface regions(without supporting 3-D model computations, however).Ba…
Influence of coronal mass ejection on geomagnetic activity during 1988–1993
Shrivastava, Pankaj Kumar; Singh, G. N.
The most rapid and dramatic evolution in the solar corona occurs in events now known as Coronal Mass Ejections (CMEs). There have considerable importance for our understanding of the evolution of the mass and energy injected into the interplanetary medium. In this work, we have studied the relation of CMEs with geomagnetic activity for the period …
The Shadow of Comet Hale-Bopp in Lyman-Alpha
Bertaux, Jean-Loup; Lallement, Rosine; Szegö, Karöly +1 more
For a few months around perihelion, the central part of the Hale-Bopp hydrogen cloud has been optically thick to the solar Lyα radiation, and has significantly reduced the solar flux available for the resonance glow of interstellar hydrogen beyond the comet. This shadowing effect on the interstellar gas is the first ever observed comet shadow. It …
Thermal Emission From The Dust Coma Of Comet Hale-Bopp And The Composition Of The Silicate Grains
Hayward, T. L.; Gehrz, R. D.; Hanner, M. S. +7 more
The dust coma of comet Hale-Bopp was observed in the thermal infrared over a wide range in solar heating (R = 4.9–0.9 AU) and over the full wavelength range from 3 µm to 160 µm. Unusual early activity produced an extensive coma containing small warm refractory grains; already at 4.9 AU, the 10 µm silicate emission feature was str…
Infrared Observations Of Volatile Molecules In Comet Hale-Bopp
Crovisier, J.
Infrared observations of comets C/1996 B2 (Hyakutake) and C/1995 O1 (Hale-Bopp) benefited from the high spectral resolution and sensitivity of échelle spectrometers now equipping ground-based telescopes and from the availability of the Infrared Space Observatory (ISO). From the ground, several hydrocarbons were unambiguously detected for the first…
A Determination of The Nuclear Size of Comet Hale–Bopp (C/1995 O1)
Sekanina, Z.
The signal of the nucleus was digitally extracted from six images of the innermost coma of this comet, obtained with the Hubble Space Telescope's Wide-Field Planetary Camera 2 in the planetary mode between October 23, 1995 and October 17, 1996. Two different anisotropic, power-type laws were used to filter out the contribution from the dust coma: …
Detection of a Satellite Orbiting The Nucleus of Comet Hale–Bopp (C/1995 O1)
Sekanina, Z.
This paper reports on the detection of a satellite around the principal nucleus of comet Hale-Bopp. As shown elsewhere, a successful morphological model for the comet's dust coma necessitates the postulation of overlapping jet activity from a comet pair. The satellite has been detected digitally on images taken with the Hubble Space Telescope's Wi…
Comet Hale-Bopp, Circumstellar Dust, and the Interstellar Medium
Waters, L. B. F. M.; Waelkens, C.; Malfait, K.
The infrared spectrum of comet Hale-Bopp, as observed with the Infrared Space Observatory (ISO), presents astonishing similarities with those of the dusty disks surrounding young stars. The prominent spectral features of crystalline silicates that occur in comets, have been observed in the circumstellar media of young and old stars, yet not in the…
The Infrared Spectrum of Comet Hele–Bopp as Seen by the Infrared Space Observatory
Altieri, B.; Keller, H. U.; Lellouch, E. +6 more
Spectra of comet C/1995 O1 (Hale-Bopp) were obtained with the Infrared Space Observatory (ISO) at medium resolution with the grating spectrometer in the photometer (PHT-S) and/or at high resolution with the short wavelength spectrometer (SWS) and long wavelength spectrometer (LWS) in April 1996 (Crovisier et al., 1996), September–October 1996 (Cro…
Ultraviolet observations of comet Hale-Bopp
Feldman, Paul D.
Ultraviolet spectroscopy and imaging of comet Hale-Bopp (C/1995 O1) were obtained from a variety of space platforms from shortly after the discovery of the comet through perihelion passage. Observations with the International Ultraviolet Explorer (IUE) and the Hubble Space Telescope (HST) spanned the range of 6.8 to 2.7 AU pre-perihelion, but IUE …