Solar radius

Solar radius

Conversion of solar radius
1 R = Units
6.955×108 metres
6.955×105 kilometres
0.0046491 astronomical unit
432,450 miles
7.351×10−8 light-year
2.254×10−8 parsec
2.3214753 light-seconds

Solar radius is a unit of distance used to express the size of stars in astronomy equal to the current radius of the Sun:

1\,R_{\odot} = 6.955\times 10^5 \hbox{ km}

The solar radius is approximately 695,500 kilometres (432,450 miles), which is about 10 times the average radius of Jupiter, 110 times the radius of the Earth, and 1/215th of an astronomical unit, the distance of Earth from the Sun. It varies slightly from pole to equator due to its rotation, which induces an oblateness of order 10 parts per million. (See 1 gigametre for similar distances.)[1]

The SOHO spacecraft was used to measure the radius of the Sun by timing transits of Mercury across the surface during 2003 and 2006. The result was a measured radius of 696,342 ± 65 kilometres (432,687 ± 40 miles).[2]

See also


  1. ^ Nasa RHESSI oblateness measurements 2012
  2. ^ Emilio, Marcelo; Kuhn, Jeff R.; Bush, Rock I.; Scholl, Isabelle F., "Measuring the Solar Radius from Space during the 2003 and 2006 Mercury Transits", arXiv, retrieved 2012-03-28 
  • S. C. Tripathy; H. M. Antia (1999). "Influence of surface layers on the seismic estimate of the solar radius". Solar Physics 186 (1/2): 1–11.  
  • T. M. Brown;