Radio & optical observation of UX Arietis Virtual Observatory Resource

Authors
  1. Elias N.M. II
  2. Quirrenbach A.
  3. Witzel A.
  4. Naundorf C.E.
  5. Wegner R.,Guinan E.F.
  6. McCook G.P.
  7. Published by
    CDS
Abstract

We have observed UX Arietis at C band (6cm) for 3 weeks with four VLA antennas. The temporal coverage during the program was approximately three scans per day. A few days into the VLA program, UX Ari began a radio flaring period which lasted for at least 2 weeks. All the radio fluxes were above the system noise during this episode, but the largest values (up to 270mJy) occurred close to 0.0 phase. This phasing is confirmed by the UX Ari radio observations of Neidhoefer, Massi, & Chiuderi-Drago (1993A&A...278L..51N). Visible-band light curves of UX Ari were obtained both during and after our radio observations; the peak-to-peak variation in all filters was ~0.2mag. The light curves indicate that the maximum starspot visibility occurred very close to 0.0 phase, the same phase as the radio maxima. Closer comparison of our radio and optical light curves indicates that they are almost perfectly anticorrelated. A similar radio/optical correlation has been found by Lim et al. (1992ApJ...388L..27L) and Lim et al. (1994ApJ...430..332L) for the single K0 V star AB Dor. We make the following conclusions from our observations. First, the episodes of long-term (~hours to days) radio flaring were modulated by stellar eclipses. Second, the flares were located close to the starspot groups. Third, the sizes of the flares were comparable to sizes of the starspot groups, which is consistent with nonthermal emission of brightness temperature T_b~10^10-10^13K. Fourth, the radio emission arose only from the midlatitude starspot groups. Last, the radio flares emitted their radiation nearly normal to the stellar surface.

Keywords
  1. stellar-flares
  2. photometry
  3. radio-astronomy
Bibliographic source Bibcode
1995ApJ...439..983E
See also HTML
https://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/439/983
IVOA Identifier IVOID
ivo://CDS.VizieR/J/ApJ/439/983
Document Object Identifer DOI
doi:10.26093/cds/vizier.14390983

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History

1997-12-09T20:51:48Z
Resource record created
1997-12-09T19:51:52Z
Updated
1997-12-09T20:51:48Z
Created

Contact

Name
CDS support team
Postal Address
CDS, Observatoire de Strasbourg, 11 rue de l'Universite, F-67000 Strasbourg, France
E-Mail
cds-question@unistra.fr