| 1. |
- Blomberg, Lars
(författare)
-
Mercury's magnetosphere, exosphere and surface : Low-frequency field and wave measurements as a diagnostic tool
- 1997
-
Ingår i: Planetary and Space Science. - 0032-0633 .- 1873-5088. ; 45:1, s. 143-148
-
Tidskriftsartikel (refereegranskat)abstract
- Diagnostics that can be made with combined electric and magnetic field measurements at Mercury are reviewed. Fundamental electrodynamic questions which can be answered by means of a Mercury Orbiter are discussed. These include, solar wind-magnetosphere coupling, coupling to low altitude, exospheric or planetary surface conductivity, auroral particle acceleration, and magnetospheric substorms. It is concluded that a comprehensive instrumentation package for low-frequency fields and waves on a future Mercury Orbiter mission may yield significant new information of interest to magnetospheric as well as to planetary physics in general. (C) 1997 Elsevier Science Ltd.
|
|
| 2. |
- Belskaya, IN, et al.
(författare)
-
Physical properties of M class asteroids
- 1996
-
Ingår i: PLANETARY AND SPACE SCIENCE. - : PERGAMON-ELSEVIER SCIENCE LTD. - 0032-0633. ; 44:8, s. 783-794
-
Tidskriftsartikel (refereegranskat)abstract
- The available data on M class asteroids have been collected and analysed. The possible number of M-asteroids in the main asteroid belt larger than 30 km was estimated to be about 90 objects. A list of the 60 asteroids currently classified as M is presente
|
|
| 3. |
- Denchev, P, et al.
(författare)
-
Lightcurves of nine asteroids, with pole and sense of rotation of 42 Isis
- 1998
-
Ingår i: PLANETARY AND SPACE SCIENCE. - : PERGAMON-ELSEVIER SCIENCE LTD. - 0032-0633. ; 46:6-7, s. 673-682
-
Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- The results of photometric observations of 9 asteroids collected from 1991 to 1997 are presented. The observations have been conducted at Belogradchik and Rozhen observatories, Bulgaria. For 42 Isis a spin pole determination has been performed: we derive
|
|
| 4. |
|
|
| 5. |
- JORDA, L, et al.
(författare)
-
COMET P/WIRTANEN, SUMMARY OF OBSERVATIONAL DATA
- 1995
-
Ingår i: PLANETARY AND SPACE SCIENCE. - : PERGAMON-ELSEVIER SCIENCE LTD. - 0032-0633. ; 43:3-4, s. 575-579
-
Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- P/Wirtanen is now the main target of the Rosetta mission. The orbit of this Jupiter family comet is perturbed by frequent approaches to Jupiter. The last one occurred in 1984, and placed the comet on an orbit with reduced perihelion distance. Since no obs
|
|
| 6. |
- Krüger, H., et al.
(författare)
-
Three years of Galileo dust data. II. 1993-1995
- 1999
-
Ingår i: Planetary and Space Science. - 1873-5088. ; 47:1-2, s. 85-106
-
Tidskriftsartikel (refereegranskat)abstract
- Between January 1993 - December 1995, the Galileo spacecraft traversed the interplanetary space between Earth and Jupiter and arrived at Jupiter on 7 December 1995. The dust instrument onboard the spacecraft was operating during most of the time and data from the instrument were obtained via memory readouts which occurred at rates between twice per day and once per week. All events were classified by an onboard program into 24 categories. Noise events were usually restricted to the lowest categories (class 0). During Galileo's passage through Jupiter's radiation belts on 7 December 1995, several of the higher categories (classes 1 and 2) also show evidence for contamination by noise. The highest categories (class 3) were noise-free all the time. A relatively constant impact rate of interplanetary and interstellar (big) particles of 0.4 impacts per day was detected over the whole three-year time span. In the outer solar system (outside about 2.6 AU) they are mostly of interstellar origin, whereas in the inner solar system they are mostly interplanetary particles. Within about 1.7 AU from Jupiter intense streams of small dust particles were detected with impact rates of up to 20,000 per day whose impact directions are compatible with a Jovian origin. Two different populations of dust particles were detected in the Jovian magnetosphere: small stream particles during Galileo's approach to the planet and big particles concentrated closer to Jupiter between the Galilean satellites. Information about 2883 particles detected by the dust instrument during Galileo's six-year journey to Jupiter is now available.
|
|
| 7. |
- Krüger, H., et al.
(författare)
-
Three years of Ulysses dust data: 1993-1995
- 1999
-
Ingår i: Planetary and Space Science. - 1873-5088. ; 47:3-4, s. 363-383
-
Tidskriftsartikel (refereegranskat)abstract
- The Ulysses spacecraft is orbiting the Sun on a highly inclined ellipse (i = 79°). After its Jupiter flyby in 1992 at a heliocentric distance of 5.4 AU, the spacecraftreapproached the inner solar system, flew over the Suns south polar region in September 1994,crossed the ecliptic plane at a distance of 1.3 AU in March 1995, and flew over the Suns northpolar region in July 1995. We report on dust impact data obtained with the dust detector onboardUlysses between January 1993 and December 1995. We publish and analyse the complete dataset of 509 recorded impacts of dust particles with masses between 10-16 g-10-7 g. Together with 968 dust impacts from launch until the end of 1992 published earlier ([Gruuml;n et al., 1995c]), information about 1477 particles detected with theUlysses sensor between October 1990 and December 1995 is now available. The impact ratemeasured between 1993 and 1995 stayed relatively constant at about 0.4 impacts per day andvaried by less than a factor of ten. Most of the impacts recorded outside about 3.5 AU arecompatible with particles of interstellar origin. Two populations of interplanetary particles havebeen recognized: big micrometer-sized particles close to the ecliptic plane and smallsub-micrometer-sized particles at high ecliptic latitudes. The observed impact rate is comparedwith a model for the flux of interstellar dust particles which gives relatively good agreement withthe observed impact rate. No change in the instruments noise characteristics or degradation of thechanneltron could be revealed during the three-year period.
|
|
| 8. |
- Lindblad, Bertil Anders
(författare)
-
The nodal, the new and the old maximum of the Perseid meteor stream
- 1998
-
Ingår i: Planetary and Space Science. - 1873-5088. ; 46:8, s. 865-868
-
Tidskriftsartikel (refereegranskat)abstract
- Visual observations of Perseid meteors carried out in 1953-83 at the Onsala Space Observatory are analyzed to study the fine structure of the Perseid meteor stream maximum. Observed hourly rates are corrected for weather conditions and to a zenithal value. The Perseid activity curve is studied (1) for all observed Perseids, (2) for Perseids of app. magnitude 2.0 or brighter. The activity curve for both data sets shows two main peaks, one at solar long. 138.65° (1950.0) , very near to the node of the parent comet (Swift-Tuttle) , and a second peak at 139.42°, corresponding to the traditional maximum of the shower. A third, less conspicuous peak at 138.96° is also evident in the data. This peak could possibly be an early indication of the so-called new maximum of the Perseid stream. The detection of a well-defined peak in rates very near to the node of the parent comet is important since the position of the Perseid visual maximum usually quoted in the literature deviates from the cometary node by almost 1° in solar longitude.
|
|
| 9. |
- Mottola, S, et al.
(författare)
-
The slow rotation of 253 Mathilde
- 1995
-
Ingår i: PLANETARY AND SPACE SCIENCE. - : PERGAMON-ELSEVIER SCIENCE LTD. - 0032-0633. ; 43:12, s. 1609-1613
-
Tidskriftsartikel (refereegranskat)abstract
- CCD photometry of the NEAR mission fly-by target 253 Mathilde is presented. Measurements taken during 52 nights of observations, from February to June 1995, allow a rotation period of 17.406 +/- 0.010 days and a lightcurve amplitude of 0.45 +/- 0.02 mag t
|
|
| 10. |
- Shevchenko, VG, et al.
(författare)
-
Asteroid observations at low phase angles. I. 50 Virginia, 91 Aegina and 102 Miriam
- 1997
-
Ingår i: PLANETARY AND SPACE SCIENCE. - : PERGAMON-ELSEVIER SCIENCE LTD. - 0032-0633. ; 45:12, s. 1615-1623
-
Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- We present observations of magnitude-phase dependences of three low-albedo asteroids down to phase angles of 0.1-0.2 degrees. Data were obtained during 40 nights from 1994 to 1995 within the joint observational program at ESO and Kharkiv Astronomical Obse
|
|
