ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
  • Other Sources  (4)
  • 2020-2022
  • 2010-2014  (1)
  • 1985-1989  (3)
Collection
Source
Keywords
Years
Year
  • 1
    facet.materialart.
    Unknown
    The origin of low mass particles within and beyond the dust coma envelopes of Comet Halley (1987)
    In:  Other Sources
    Details
    Publication Date: 2019-06-28
    Description: Measurements from the Dust Counter and Mass Analyzer (DUCMA) instruments on VEGA-1 and -2 revealed unexpected fluxes of low mass (up to 10 to the minus 13th power g) dust particles at very great distances from the nucleus (300,000 to 600,000 km). These particles are detected in clusters (10 sec duration), preceded and followed by relatively long time intervals during which no dust is detected. This cluster phenomenon also occurs inside the envelope boundaries. Clusters of low mass particles are intermixed with the overall dust distribution throughout the coma. The clusters account for many of the short-term small-scale intensity enhancements previously ascribed to microjets in the coma. The origin of these clusters appears to be emission from the nucleus of large conglomerates which disintegrate in the coma to yield clusters of discrete, small particles continuing outward to the distant coma.
    Keywords: LUNAR AND PLANETARY EXPLORATION
    Type: ESA, Proceedings of the International Symposium on the Diversity and Similarity of Comets; p 391-397
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 2
    facet.materialart.
    Unknown
    A source map for dust jets observed in the coma of Comet P/Halley (1988)
    In:  Other Sources
    Details
    Publication Date: 2019-07-12
    Description: In this paper, the large-scale enhancements of about 50 s duration in the flux of submicron dust particles from Comet P/Halley recorded by the Dust Counter and Mass Analyzer carried aboard the two Vega spaceprobes are traced back to their source departure points on the nucleus. Evidence is presented that such enhancements which correspond to regions of enhanced particle density in the coma with spatial widths of about 4000 km, are superimposed upon a background flux distribution which is well described by a simple fountain model. Thus, dust production on the sunlit hemisphere of the nucleus is characterized by discrete jet sources superimposed upon relatively low-level isotropic emission. The jet sources at the nucleus responsible for the major enhancements in recorded particle impact rates are narrow and discrete, with each jet accelerating about 10 to the -13th g particles to a narrow range of terminal velocities which decrease with increasing particle mass.
    Keywords: ASTROPHYSICS
    Type: Astronomy and Astrophysics (ISSN 0004-6361); 200; 1-2; 225-247
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 3
    facet.materialart.
    Unknown
    The UT 7/8 February 2013 Sila-Nunam Mutual Event and Future Predictions (2013)
    In:  CASI
    Details
    Publication Date: 2019-07-13
    Description: A superior mutual event of the Kuiper Belt binary system (79360) Sila-Nunam was observed over 15.47 h on UT 7/8 February 2013 by a coordinated effort at four different telescope facilities; it started approximately 1.5 h earlier than anticipated, the duration was approximately 9.5 h (about 10% longer than predicted), and was slightly less deep than predicted. It is the first full event observed for a comparably sized binary Kuiper Belt object. We provide predictions for future events refined by this and other partial mutual event observations obtained since the mutual event season began.
    Keywords: Lunar and Planetary Science and Exploration
    Type: GSFC-E-DAA-TN22027 , Icarus; 229; 423-427
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 4
    facet.materialart.
    Unknown
    The dust coma of comet P/Halley - Measurements on the Vega-1 and Vega-2 spacecraft (1987)
    In:  Other Sources
    Details
    Publication Date: 2019-07-12
    Description: Measurements obtained with the Dust Counter and Mass Analyzer instruments on the Vega 1 and 2 spacecraft are used to study properties of the coma of comet P/Halley. Well-defined envelope boundaries for the inverse square dependence of flux with distance from the nucleus are found, and regions of enhanced fluxes above these R exp -2 baselines inside these boundaries are identified as dust jets. The mass spectrum of the giant flux enhancement noted near the closest approach of Vega 1 is shown to be similar to the preencounter spectra. The data suggest the emission from the nucleus of large conglomerates of small particles which disintegrate as they travel outward, explaining the 10 to the -13th g particles observed beyond the envelope boundaries.
    Keywords: ASTROPHYSICS
    Type: Astronomy and Astrophysics (ISSN 0004-6361); 187; 1-2; 742-752
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...