Solar radius variations: new look on the wavelength dependence


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Rozelot J., Kosovichev A., KILÇIK A.

319th Symposium of the International-Astronomical-Union (IAUS) / 320th Symposium of the International-Astronomical-Union (IAUS), Hawaii, Amerika Birleşik Devletleri, 11 - 14 Ağustos 2015, cilt.11, ss.342-350 identifier identifier

  • Yayın Türü: Bildiri / Tam Metin Bildiri
  • Cilt numarası: 11
  • Doi Numarası: 10.1017/s1743921316002118
  • Basıldığı Şehir: Hawaii
  • Basıldığı Ülke: Amerika Birleşik Devletleri
  • Sayfa Sayıları: ss.342-350
  • Anahtar Kelimeler: astrometry, Sun: general, Sun: fundamental parameters, Sun: photosphere, Sun: radio radiation, SUN, DIAMETER
  • Akdeniz Üniversitesi Adresli: Evet

Özet

The possibility that the Sun's radius is changing, even at a faint level, has been discussed over a long time. As the solar radius is certainly one of the most important basic pieces of astrophysical information, it is crucial to determine the physical mechanisms that may cause shrinking or expansion of the solar envelope. The wavelength dependence has been poorly inspected up to now. Here we examine recent solar radius determinations from space observations, mainly from Mercury and Venus transits, made by different teams in 2006, 2012 and 2014. Seemingly, the results are not consistent: authors interpreted the discrepancies because of the different methods of analysis used in their work. However, looking at the wavelength dependence, adding other available observations, from X-EUV up to radio, a typical relationship between the radius and the wavelength can be found, reflecting the different heights at which the lines are formed. Possible explanations are discussed. Such results can be interesting for studying solar-stellar connections.