AAVSO: American Association of Variable Star Observers

Should We Try to Re-Construct the American Relative Sunspot Index (Ra)? (Abstract)

Volume 44 number 1 (2016)

Rodney Howe
3343 Riva Ridge Drive, Fort Collins, CO 80526; ahowe@frii.com


(Abstract only) The new correction of the international sunspot number (ISN), called the Sunspot Number Version 2.0, led by Frédéric Clette (Director of the World Data Centre [WDC]-SILSO), Ed Cliver (National Solar Observatory), and Leif Svalgaard (Stanford University), nullifies the claim that there has been a Modern Grand Maximum. This comes from the International Astronomical Union (IAU) press release, August 2015 (http://www.iau.org/news/pressreleases/detail/iau1508/). This ISN re-construction raises some questions for the AAVSO: should we try to re-construct the American Relative Index (Ra) to go along with the ISN reconstruction? Here we present the historical and current reconstructed ISN, with comparisons to the AAVSO American Relative Ra Index. If the AAVSO decides to re-construct the American Ra Index, then it will be important to digitize all available data back to 1947 and up to 2000 (the AAVSO currently has digitized data from 2000 to present). These archives exist at AAVSO HQ in different formats of raw observations from many observers over the past 70 years. However, not all raw data used since 1947 are extant.