Solar Section        


Solar Ephemeris and Commencement dates/times for Carrington Rotations



Several factors play a role why we do not see the Central Meridian and Equator of the Sun lined up in the center of the face of the Sun when we make our observations from Earth. Such factors include the tilt of the Sun relative to our orbit, as well as the rotation of the Sun corrected for the slightly elliptical orbit of Earth around the Sun. In order to determine exactly the location of a feature on the Sun, we need to consider these deviations in determining the true heliographic coordinates of the features:

  • Lo – the heliographic longitude of the center of the disk – this decreases by an average value of 13.2° per day,
  • Po – the position angle of the north end of the axis of rotation, measured + if east of the north point of the disk,
  • Bo – the heliographic latitude of the center of the disk,
  • Diameter the apparent diameter of the Sun

Daily ephemeris information for 2016 is available in table form by clicking in pdf form by clicking here, or if you would like to download the file for off line access, right click here to download the .pdf version.

Another resource we provide Observers, is the beginning date/time of Carrington Rotations. Contrary to Bartel’s Rotations, Carrington Rotations start at odd times during the day. In order to identify your observation with the correct CR Number, please consult the short file for commencement dates and times for the CRs between 2015 and 2025, or CR2159 to CR2306.

For longer term analysis or research, we also provide a file containing the same data for rotations between 1853 and 2083 or the Rotations CR-10 and CR3082.

All Ephemeris tables and files on this page were calculated by using WIMP, a program by Jeff Beish and they give the heliographic coordinates for the “center” of the Sun at the given date at Universal Time 00:00 UT.
WIMP can be downloaded from the Mars Observer’s Café Site, as well as the A.L.P.O. Computer Section.

Past Years Ephemerides

All ephemerides Computed by Brad Timerson, A.L.P.O. Solar Section 1997-2014.

2015 Emphemeris
ALPO Solar Ephemeris for 2015 pdf format

2014 Emphemeris
ALPO Solar Ephemeris for 2014 pdf format

2013 Emphemeris
ALPO Solar Ephemeris for 2013 pdf format

2012 Emphemeris
ALPO Solar Ephemeris for 2012 pdf format

2011 Emphemeris
ALPO Solar Ephemeris for 2011 pdf format

2010 Emphemeris
ALPO Solar Ephemeris for 2010 pdf format
2009 Emphemeris
ALPO Solar Ephemeris for 2009 pdf format
2008 Emphemeris
ALPO Solar Ephemeris for 2008 pdf format
2007 Emphemeris
2006 Emphemeris
2005 Emphemeris
2004 Emphemeris
2003 Emphemeris
2002 Emphemeris
2001 Emphemeris
2000 Emphemeris
1999 Emphemeris
1998 Emphemeris
1997 Emphemeris

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