Measurement of Solar Limb Darkening at Hydrogen Alpha

Ajraini Nazli, Nadiya Rahma Ardilla

Abstract


Sun disc has a lower intensity at the limb where it looks darker than at the center. This effect known as solar limb darkening. In this study, we determine the solar limb darkening at hydrogen alpha with 656 nm thus we can compare the result to the previous studies. We have taken the solar images at Observatorium Ilmu Falak Universitas Muhammadiyah Sumatera Utara (OIF UMSU). Limb-darkening coefficient is obtained through least-square fitting with the linear limb-darkening law. The result shows linear limb-darkening coefficient is 0.607 and it gives good agreement with the previous studies. In addition, this study is the initial stage of limb darkening research at OIF UMSU and can be continued with more observational data.

Full Text:

Download PDF Here

References


Milne E.A, Radiative Equilibrium in the Outer Layers of a Star: the Temperature Distribution and the Law of Darkening MNRAS, vol. 81, p. 361, 1921.

R. R. M. L. G. and O. C. M. A. K. Pierce, Observations Of Solar Limb Darkening Between 0.5 And 10.2, Astrophysical Journal, vol. 112, pp. 289–298, 1950.

Pan Kai-Ke, Tan Hui-Song, The standard systems of the determinations of stellar rotational velocities (II),” Acta Astronomica Sinica , vol. 34, pp. 164–172, 1993.

F. Sánchez-Bajo, J. M. Vaquero, and R. Montero, Measuring solar limb-darkening with modest equipment, Eur.J.Phys, vol 23, pp. 323-330, 2002

W. van Hamme, New Limb-Darkening Coefficients For Modeling Binary Star Light Curves, Astron. J, vol. 106, pp. 2096-117, 1993.

A.S. Ramanthan , Study of The Continuous Solar Spectrum in The Visible Range, Annales d'Astrophysique, vol. 17, pp. 18, 1954.

J. Grygar, Application of The Non-Linear Laws of Limb Darkening on Eclipsing Binaries. Bull. Astron.Inst, vol. 16, 1965.

Manduca, A., Bell, R.A., Gustafsson, B., Limb Darkening Coefficients for Late-type Giant Model Atmospheres, Astron.Astrophys, vol. 61, pp. 809, 1977.

A. Claret, Comprehensive tables for the interpretation and modeling of the light curves of eclipsing binaries, Astronomy and Astrophysics Supplement, vol. 131, pp. 395-400, 1998.

Keith Pierce,, Allen’s Astrophysical Quantities. Springer New York, 2002. doi: 10.1007/978-1-4612-1186-0.

B. Moon, D. G. Jeong, S. Oh, and J. Sohn, Variation in solar limb darkening coefficient estimated from solar images taken by SOHO and SDO, Journal of Astronomy and Space Sciences, vol. 34, no. 2, pp. 99–103, Jun. 2017, doi: 10.5140/JASS.2017.34.2.99.

A. K. Tripathi, S. Chaubey, and A. K. Singh,Study of Limb Darkening Effect and Rotation Period of Sun by using Solar Telescope, Journal of scientific research, vol. 64, no. 01, pp. 122–126, 2020, doi: 10.37398/jsr.2020.640132.


Refbacks

  • There are currently no refbacks.


Copyright (c) 2024 Al-Hisab: Journal of Islamic Astronomy

Creative Commons License
This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License.