Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Radio Interferometric Observation of an Asteroid Occultation
Department of Physics, University of Helsinki, Finland. Max-Planck-Institut für extraterrestrische Physik, Garching, Germany.ORCID iD: 0000-0002-1189-9790
Finnish Geospatial Research Institute FGI, Masala, Finland.ORCID iD: 0000-0002-1004-8898
Long Baseline Observatory, Socorro, USA.ORCID iD: 0000-0003-4410-5421
Astrogeo Center, Falls Church, USA.
Show others and affiliations
2018 (English)In: Astronomical Journal, ISSN 0004-6256, E-ISSN 1538-3881, Vol. 156, no 4, p. 1-10, article id 155Article in journal (Refereed) Published
Abstract [en]

The occultation of the radio galaxy 0141+268 by the asteroid(372)Palma on 2017 May 15 was observed using sixantennas of the Very Long Baseline Array(VLBA). The shadow of Palma crossed the VLBA station at Brewster,Washington. Owing to the wavelength used, and the size and the distance of the asteroid, a diffraction pattern in theFraunhofer regime was observed. The measurement retrieves both the amplitude and the phase of the diffractedelectromagnetic wave. This is thefirst astronomical measurement of the phase shift caused by diffraction. Themaximum phase shift is sensitive to the effective diameter of the asteroid. The bright spot at the shadow’s center,the so called Arago–Poisson spot, is clearly detected in the amplitude time-series, and its strength is a goodindicator of the closest angular distance between the center of the asteroid and the radio source. A sample ofrandom shapes constructed using a Markov chain Monte Carlo algorithm suggests that the silhouette of Palmadeviates from a perfect circle by 26±13%. The best-fitting random shapes resemble each other, and we suggesttheir average approximates the shape of the silhouette at the time of the occultation. The effective diameterobtained for Palma, 192.1±4.8 km, is in excellent agreement with recent estimates from thermal modeling ofmid-infrared photometry. Finally, our computations show that because of the high positional accuracy, a singleradio interferometric occultation measurement can reduce the long-term ephemeris uncertainty by an order ofmagnitude.

Place, publisher, year, edition, pages
University of Chicago Press, 2018. Vol. 156, no 4, p. 1-10, article id 155
National Category
Other Electrical Engineering, Electronic Engineering, Information Engineering
Research subject
Onboard space systems
Identifiers
URN: urn:nbn:se:ltu:diva-70978DOI: 10.3847/1538-3881/aad45bISI: 000444698500001Scopus ID: 2-s2.0-85054801851OAI: oai:DiVA.org:ltu-70978DiVA, id: diva2:1250827
Note

Validerad;2018;Nivå 2;2018-10-03 (marisr)

Available from: 2018-09-25 Created: 2018-09-25 Last updated: 2019-03-27Bibliographically approved

Open Access in DiVA

No full text in DiVA

Other links

Publisher's full textScopus

Authority records BETA

Granvik, Mikael

Search in DiVA

By author/editor
Harju, JormaLehtinen, KimmoRomney, JonathanGranvik, MikaelBach, Uwe
By organisation
Space Technology
In the same journal
Astronomical Journal
Other Electrical Engineering, Electronic Engineering, Information Engineering

Search outside of DiVA

GoogleGoogle Scholar

doi
urn-nbn

Altmetric score

doi
urn-nbn
Total: 8 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf