Proceedings of the International Astronomical Union. "The Sun and Stars as the Primary Energy Input in Planetary Atmospheres" (PDF). ^ NASA RHESSI oblateness measurements 2012.Solar radii as a unit are common when describing spacecraft moving close to the sun. The nominal value, which is the rounded value, within the uncertainty, given by Haberreiter, Schmutz & Kosovichev (2008), was adopted to help astronomers avoid confusion when quoting stellar radii in units of the Sun's radius, even when future observations will likely refine the Sun's actual photospheric radius (which is currently only known to about an accuracy of ± 100–200 km).
Resolution B3 defined the nominal solar radius (symbol R ⊙ N ) to be equal to exactly 695 700 km. In 2015, the International Astronomical Union passed Resolution B3, which defined a set of nominal conversion constants for stellar and planetary astronomy.
This new value is consistent with helioseismic estimates the same study showed that previous estimates using inflection point methods had been overestimated by approximately 300 km (190 mi). Haberreiter, Schmutz & Kosovichev (2008) determined the radius corresponding to the solar photosphere to be 695,660 ± 140 kilometres (432,263 ± 87 miles).
The uncrewed SOHO spacecraft was used to measure the radius of the Sun by timing transits of Mercury across the surface during 20. Evolution of the solar luminosity, radius and effective temperature compared to the present-day Sun.
0 kommentar(er)
