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Potansiyel Bir SPB Yıldızı Olan η Tau Yıldızının Frekans Analizi

Year 2018, , 72 - 82, 30.11.2018
https://doi.org/10.29233/sdufeffd.440797

Abstract

Bu çalışmada, η Tau yıldızının 2007 ile 2011 yılları
arasında
STEREO uydusundan alınan beş
yıllık fotometrik verileri sunulmaktadır. Yüksek duyarlılığa sahip veriler,
yıldızdaki Be olgusunu daha iyi anlamak için tayfsal bulgulardan elde edilen
sonuçlarla karşılaştırılmıştır. Tayfsal veriler fotometrik gözlemlerle aynı
zaman aralığını kapsamaktadır. η Tau, tayflarında çift pikli Hα salma profili
göstermektedir. Bu profili analiz etmek için, Hα salma çizgileri, eşdeğer
genişlikleri ve çizgi şiddetleri ölçülerek incelenmiştir. Fotometrik ve
spektroskopik analizler sonucunda, yıldızın frekans dağılımı ve genlik şiddetlerinin
tipik bir Be yıldızından farklı olduğu ortaya çıkmıştır. Sıcaklık ve parlaklık
değerleri gibi fiziksel parametrelerine dayanarak yıldızın Yavaş Zonklayan B
tipi bir emisyon yıldızı olduğu sonucuna varılabilir. Öte yandan, emisyon
çizgilerinin eşdeğer genişlik değerleri, salınım frekansları ve genlikleri ile
ilişkili görünmektedir. Bu da, fotometrik değişimlerin çevresel disk yapısıyla
ilişkili olabileceğini göstermektedir


Doğuş ÖZUYAR, dozuyar@ankara.edu.tr,
ORCID: https://orcid.org/
0000-0001-8544-0950

References

  • M. Jaschek, C. Jaschek, A. M. Hubert-Delplace, and H. Hubert, “A classification of Be stars,” Astronomy and Astrophysics Supplement Series, vol. 42, pp.103-114, October 1980.
  • O. Struve, “On the Origin of Bright Lines in Spectra of Stars of Class B,” Astrophys. J., vol. 73, pp. 94, March 1931.
  • J. M. Porter and T. Rivinius, “Classical Be Stars,” Publ. Astron. Soc. Pac., vol. 115, pp. 1153-1170, October 2003.
  • A. C. Carciofi, A. T. Okazaki, J. B. Le Bouquin, S. Stefl, T. Rivinius, D. Baade, J. E. Bjorkman, and C. A. Hummel, “Cyclic variability of the circumstellar disk of the Be star ζ Tauri. II. Testing the 2D global disk oscillation model,” Astron. Astrophys., 504:915-927, September 2009.
  • S. R. Cranmer, “A Pulsational Mechanism for Producing Keplerian Disks Around Be Stars,” Astrophys. J., vol. 701, pp. 396-413, August 2009.
  • T. A. A. Sigut and P. Patel, “The Correlation between Hα Emission and Visual Magnitude during Long-term Variations in Classical Be Stars”, Astrophys. J., vol. 765, pp. 41, March 2013.
  • R. H. D. Townsend, S. P. Owocki, and I. D. Howarth, “Be-star rotation: how close to critical?,” Mon. Not. R. Astron. Soc., vol. 350, pp. 189-195, May 2004.
  • H. A. Abt and O. Cardona, “Be stars in binaries,” Astrophys. J., vol. 285, pp. 190-194, October 1984.
  • A. M. Hubert-Delplace and H. Hubert, “An atlas of Be stars”, Paris-Meudon Observatory, 1979.
  • A. Slettebak and R. C. Reynolds, “Halpha variations in spectra of the brighter, northern Be stars”, Astrophysical Journal Supplement Series, vol. 38, pp. 205-228, November 1978.
  • Y. Andrillat and C. Fehrenbach, “Study of H-alpha profile in 72 Be stars”, Astronomy and Astrophysics Supplement Series, vol. 48, pp. 93-136, April 1982.
  • M. M. Jarad, R. W. Hilditch, and I. Skillen, “A radial-velocity study of 18 emission-line B stars”, Monthly Notices of the Royal Astronomical Society, vol. 238, pp. 1085-1106, June 1989.
  • K. M. V. Apparao, S. P. Tarafdar, R. P. Verma, K. V. K. Iyengar, and K. K. Ghosh, “Simultaneous infrared and H-alpha measurements of Be stars”, J. Astrophys. Astron., vol. 14, pp. 131-134, December 1993.
  • D. P. K. Banerjee, S. D. Rawat, and P. Janardhan, “Hα observations of Be stars,” Astronomy and Astrophysics Supplement Series, vol. 147, pp. 229-242, December 2000.
  • C. Tycner, J. B. Lester, A. R. Hajian, J. T. Armstrong, J. A. Benson, G. C. Gilbreath, D. J. Hutter, T. A. Pauls, and N. M. White, “Properties of the Hα-emitting Circumstellar Regions of Be Stars,” Astrophys. J., vol. 624, pp. 359-371, May 2005.
  • J. Cote and L. B. F. M. Waters, “IRAS observations of Be stars. I - Statistical study of the IR excess of 101 Be stars,” Astron. Astrophys., vol. 176, pp. 93-106, April 1987.
  • P. S. Goraya, N. Kumar, B. S. Salaria, and H. S. Ghumman, “Spectroscopic Study of Four Members of Balmer Series in Be Stars”, Asian J. of Chem., vol. 21, pp. 184-187, March 2009.
  • C. E. Jones, C. Tycner, and A. D. Smith, “The Variability of Hα Equivalent Widths in Be Stars,” Astron. J., vol. 141, pp. 150, May 2011.
  • C. J. Eyles, R. A. Harrison, C. J. Davis, N. R. Waltham, B. M. Shaughnessy, H. C. A. Mapson-Menard, D. Bewsher, S. R. Crothers, J. A. Davies, G. M. Simnett, R. A. Howard, J. D. Moses, J. S. Newmark, D. G. Socker, J.-P. Halain, J.-M. Defise, E. Mazy, and P. Rochus, “The Heliospheric Imagers Onboard the STEREO Mission,” Sol. Phys., vol. 254, pp. 387-445, February 2009.
  • V. Sangaralingam and I. R. Stevens, “STEREO TRansiting Exoplanet and Stellar Survey (STRESS) - I. Introduction and data pipeline,” Mon. Not. R. Astron. Soc., vol. 418, pp. 1325-1334, December 2011.
  • G. N. Whittaker, “The Analysis and Removal of Systematic Trends in STEREOs HI-1A Photometry and a Search for Planetary Transits”, PhD thesis, Astrophysics and Space Research Group, School of Physics and Astronomy, The University of Birmingham, December 2013.
  • N. Rossat, N. Delmotte, N. Fourniol, B. Pirenne, and A. Dobrzycki, Astronomical Data Analysis Software and Systems XIV, vol. 347, pp.674, 2005.
  • A. Slettebak, “H-alpha and near-infrared spectra of late-type Be and A F-type shell stars”, Astr. Soc. Pac., vol. 98, pp. 867-871, September 1986.
  • J. R. Percy, “Understanding Variable Stars”, Cambridge: Cambridge University Press, xxi, 350, ISBN: 9780521232531 (hbk.), May 2007.
  • H. Saio, “Prospects for Asteroseismology of Rapidly Rotating B-Type Stars”. In M. Goupil, K. Belkacem, C. Neiner, F. Ligni`eres, and J. J. Green, editors, Lecture Notes in Physics, Berlin Springer Verlag, vol. 865 of Lecture Notes in Physics, Berlin Springer Verlag, pp. 159, 2013.
  • Y. Fremat, J. Zorec, A. M. Hubert, and M. Floquet, “Effects of gravitational darkening on the determination of fundamental parameters in fast-rotating B-type stars”, Astronomy and Astrophysics, vol. 440, pp. 305-320, September 2005.
  • P. J. Flower, “Transformations from Theoretical H-R Diagrams to C-M Diagrams,” Astronomy and Astrophysics, vol. 54, pp. 31, January 1977.

Frequency Analysis of a Potential SPB Star η Tau

Year 2018, , 72 - 82, 30.11.2018
https://doi.org/10.29233/sdufeffd.440797

Abstract

In this study, five years of photometric data of η Tau
obtained from the
STEREO satellite
between 2007 and 2011 are presented. The high-precision data are compared with
the results derived from the spectroscopic findings to gain a better
understanding of the Be phenomenon in the star. The spectroscopic data cover
the same time interval as the photometric observations. η Tau displays a double
peaked Hα emission profile in its spectra. In order to analyze this profile,
the Hα emission lines are examined by measuring their equivalent widths and
line intensities. As a result of the photometric and spectroscopic analyses, it
is revealed that the frequency distribution and amplitude intensities of the
star are different from those of a typical Be star. Based on its physical
parameters such as temperature and luminosity values, it may be conclude that
the star is a Slowly Pulsating B type emission star. On the other hand, the
equivalent width values of the emission lines appear to be related to the
oscillation frequencies and their amplitudes. This indicates that the
photometric variations may be related to the environmental disc structure.


Doğuş ÖZUYAR, dozuyar@ankara.edu.tr, ORCID: https://orcid.org/ 0000-0001-8544-0950

References

  • M. Jaschek, C. Jaschek, A. M. Hubert-Delplace, and H. Hubert, “A classification of Be stars,” Astronomy and Astrophysics Supplement Series, vol. 42, pp.103-114, October 1980.
  • O. Struve, “On the Origin of Bright Lines in Spectra of Stars of Class B,” Astrophys. J., vol. 73, pp. 94, March 1931.
  • J. M. Porter and T. Rivinius, “Classical Be Stars,” Publ. Astron. Soc. Pac., vol. 115, pp. 1153-1170, October 2003.
  • A. C. Carciofi, A. T. Okazaki, J. B. Le Bouquin, S. Stefl, T. Rivinius, D. Baade, J. E. Bjorkman, and C. A. Hummel, “Cyclic variability of the circumstellar disk of the Be star ζ Tauri. II. Testing the 2D global disk oscillation model,” Astron. Astrophys., 504:915-927, September 2009.
  • S. R. Cranmer, “A Pulsational Mechanism for Producing Keplerian Disks Around Be Stars,” Astrophys. J., vol. 701, pp. 396-413, August 2009.
  • T. A. A. Sigut and P. Patel, “The Correlation between Hα Emission and Visual Magnitude during Long-term Variations in Classical Be Stars”, Astrophys. J., vol. 765, pp. 41, March 2013.
  • R. H. D. Townsend, S. P. Owocki, and I. D. Howarth, “Be-star rotation: how close to critical?,” Mon. Not. R. Astron. Soc., vol. 350, pp. 189-195, May 2004.
  • H. A. Abt and O. Cardona, “Be stars in binaries,” Astrophys. J., vol. 285, pp. 190-194, October 1984.
  • A. M. Hubert-Delplace and H. Hubert, “An atlas of Be stars”, Paris-Meudon Observatory, 1979.
  • A. Slettebak and R. C. Reynolds, “Halpha variations in spectra of the brighter, northern Be stars”, Astrophysical Journal Supplement Series, vol. 38, pp. 205-228, November 1978.
  • Y. Andrillat and C. Fehrenbach, “Study of H-alpha profile in 72 Be stars”, Astronomy and Astrophysics Supplement Series, vol. 48, pp. 93-136, April 1982.
  • M. M. Jarad, R. W. Hilditch, and I. Skillen, “A radial-velocity study of 18 emission-line B stars”, Monthly Notices of the Royal Astronomical Society, vol. 238, pp. 1085-1106, June 1989.
  • K. M. V. Apparao, S. P. Tarafdar, R. P. Verma, K. V. K. Iyengar, and K. K. Ghosh, “Simultaneous infrared and H-alpha measurements of Be stars”, J. Astrophys. Astron., vol. 14, pp. 131-134, December 1993.
  • D. P. K. Banerjee, S. D. Rawat, and P. Janardhan, “Hα observations of Be stars,” Astronomy and Astrophysics Supplement Series, vol. 147, pp. 229-242, December 2000.
  • C. Tycner, J. B. Lester, A. R. Hajian, J. T. Armstrong, J. A. Benson, G. C. Gilbreath, D. J. Hutter, T. A. Pauls, and N. M. White, “Properties of the Hα-emitting Circumstellar Regions of Be Stars,” Astrophys. J., vol. 624, pp. 359-371, May 2005.
  • J. Cote and L. B. F. M. Waters, “IRAS observations of Be stars. I - Statistical study of the IR excess of 101 Be stars,” Astron. Astrophys., vol. 176, pp. 93-106, April 1987.
  • P. S. Goraya, N. Kumar, B. S. Salaria, and H. S. Ghumman, “Spectroscopic Study of Four Members of Balmer Series in Be Stars”, Asian J. of Chem., vol. 21, pp. 184-187, March 2009.
  • C. E. Jones, C. Tycner, and A. D. Smith, “The Variability of Hα Equivalent Widths in Be Stars,” Astron. J., vol. 141, pp. 150, May 2011.
  • C. J. Eyles, R. A. Harrison, C. J. Davis, N. R. Waltham, B. M. Shaughnessy, H. C. A. Mapson-Menard, D. Bewsher, S. R. Crothers, J. A. Davies, G. M. Simnett, R. A. Howard, J. D. Moses, J. S. Newmark, D. G. Socker, J.-P. Halain, J.-M. Defise, E. Mazy, and P. Rochus, “The Heliospheric Imagers Onboard the STEREO Mission,” Sol. Phys., vol. 254, pp. 387-445, February 2009.
  • V. Sangaralingam and I. R. Stevens, “STEREO TRansiting Exoplanet and Stellar Survey (STRESS) - I. Introduction and data pipeline,” Mon. Not. R. Astron. Soc., vol. 418, pp. 1325-1334, December 2011.
  • G. N. Whittaker, “The Analysis and Removal of Systematic Trends in STEREOs HI-1A Photometry and a Search for Planetary Transits”, PhD thesis, Astrophysics and Space Research Group, School of Physics and Astronomy, The University of Birmingham, December 2013.
  • N. Rossat, N. Delmotte, N. Fourniol, B. Pirenne, and A. Dobrzycki, Astronomical Data Analysis Software and Systems XIV, vol. 347, pp.674, 2005.
  • A. Slettebak, “H-alpha and near-infrared spectra of late-type Be and A F-type shell stars”, Astr. Soc. Pac., vol. 98, pp. 867-871, September 1986.
  • J. R. Percy, “Understanding Variable Stars”, Cambridge: Cambridge University Press, xxi, 350, ISBN: 9780521232531 (hbk.), May 2007.
  • H. Saio, “Prospects for Asteroseismology of Rapidly Rotating B-Type Stars”. In M. Goupil, K. Belkacem, C. Neiner, F. Ligni`eres, and J. J. Green, editors, Lecture Notes in Physics, Berlin Springer Verlag, vol. 865 of Lecture Notes in Physics, Berlin Springer Verlag, pp. 159, 2013.
  • Y. Fremat, J. Zorec, A. M. Hubert, and M. Floquet, “Effects of gravitational darkening on the determination of fundamental parameters in fast-rotating B-type stars”, Astronomy and Astrophysics, vol. 440, pp. 305-320, September 2005.
  • P. J. Flower, “Transformations from Theoretical H-R Diagrams to C-M Diagrams,” Astronomy and Astrophysics, vol. 54, pp. 31, January 1977.
There are 27 citations in total.

Details

Primary Language English
Subjects Metrology, Applied and Industrial Physics
Journal Section Makaleler
Authors

Doğuş Özuyar 0000-0001-8544-0950

Publication Date November 30, 2018
Published in Issue Year 2018

Cite

IEEE D. Özuyar, “Frequency Analysis of a Potential SPB Star η Tau”, Süleyman Demirel University Faculty of Arts and Science Journal of Science, vol. 13, no. 2, pp. 72–82, 2018, doi: 10.29233/sdufeffd.440797.