Complex behaviour of the δ Scuti star θ Tucanae. I. Frequencies in the light variation

M. Paparó, C. Sterken, H. W W Spoon, P. V. Birch

Research output: Contribution to journalArticle

14 Citations (Scopus)

Abstract

On the basis of more than 2300 new Strömgren y and Johnson V photometric observations collected during 246 hours spread over 42 nights at three sites in 1993, we present a frequency analysis of the light variation of θ Tuc. 10 frequencies were found in the range of 15.8 to 20.28 cycles/day displaying an extreme regularity. Frequencies are situated in groups and these groups are equally spaced. Some kind of splitting is definitely involved. The frequencies are constant in amplitude on a short time scale. Two frequencies, 0.282 and 0.142 cycles/day (3.56 and 7.04 days period) were found to be responsible for the mean light level variation of θ Tuc. Although θ Tuc is known as a single star, the length and shape of the mean light level variation and the unusual behaviour of θ Tuc in ultraviolet and infrared suggest that the äScuti star θ Tuc is a primary in a binary system with a late F type companion.

Original languageEnglish
Pages (from-to)400-410
Number of pages11
JournalAstronomy and Astrophysics
Volume315
Issue number3
Publication statusPublished - Nov 20 1996

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stars
frequency analysis
cycles
timescale
regularity
night

Keywords

  • Infrared: stars
  • Stars: binaries: general
  • Stars: individual: θ Tuc = HR 139
  • Stars: oscillations
  • Stars: variables: δ Scuti
  • Ultraviolet: stars

ASJC Scopus subject areas

  • Space and Planetary Science

Cite this

Complex behaviour of the δ Scuti star θ Tucanae. I. Frequencies in the light variation. / Paparó, M.; Sterken, C.; Spoon, H. W W; Birch, P. V.

In: Astronomy and Astrophysics, Vol. 315, No. 3, 20.11.1996, p. 400-410.

Research output: Contribution to journalArticle

Paparó, M. ; Sterken, C. ; Spoon, H. W W ; Birch, P. V. / Complex behaviour of the δ Scuti star θ Tucanae. I. Frequencies in the light variation. In: Astronomy and Astrophysics. 1996 ; Vol. 315, No. 3. pp. 400-410.
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AB - On the basis of more than 2300 new Strömgren y and Johnson V photometric observations collected during 246 hours spread over 42 nights at three sites in 1993, we present a frequency analysis of the light variation of θ Tuc. 10 frequencies were found in the range of 15.8 to 20.28 cycles/day displaying an extreme regularity. Frequencies are situated in groups and these groups are equally spaced. Some kind of splitting is definitely involved. The frequencies are constant in amplitude on a short time scale. Two frequencies, 0.282 and 0.142 cycles/day (3.56 and 7.04 days period) were found to be responsible for the mean light level variation of θ Tuc. Although θ Tuc is known as a single star, the length and shape of the mean light level variation and the unusual behaviour of θ Tuc in ultraviolet and infrared suggest that the äScuti star θ Tuc is a primary in a binary system with a late F type companion.

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